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2023-07-19watch_queue: prevent dangling pipe pointerSiddh Raman Pant
commit 943211c87427f25bd22e0e63849fb486bb5f87fa upstream. NULL the dangling pipe reference while clearing watch_queue. If not done, a reference to a freed pipe remains in the watch_queue, as this function is called before freeing a pipe in free_pipe_info() (see line 834 of fs/pipe.c). The sole use of wqueue->defunct is for checking if the watch queue has been cleared, but wqueue->pipe is also NULLed while clearing. Thus, wqueue->defunct is superfluous, as wqueue->pipe can be checked for NULL. Hence, the former can be removed. Tested with keyutils testsuite. Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Siddh Raman Pant <code@siddh.me> Acked-by: David Howells <dhowells@redhat.com> Message-Id: <20230605143616.640517-1-code@siddh.me> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-19bpf, btf: Warn but return no error for NULL btf from ↵SeongJae Park
__register_btf_kfunc_id_set() [ Upstream commit 3de4d22cc9ac7c9f38e10edcf54f9a8891a9c2aa ] __register_btf_kfunc_id_set() assumes .BTF to be part of the module's .ko file if CONFIG_DEBUG_INFO_BTF is enabled. If that's not the case, the function prints an error message and return an error. As a result, such modules cannot be loaded. However, the section could be stripped out during a build process. It would be better to let the modules loaded, because their basic functionalities have no problem [0], though the BTF functionalities will not be supported. Make the function to lower the level of the message from error to warn, and return no error. [0] https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion Fixes: c446fdacb10d ("bpf: fix register_btf_kfunc_id_set for !CONFIG_DEBUG_INFO_BTF") Reported-by: Alexander Egorenkov <Alexander.Egorenkov@ibm.com> Suggested-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/87y228q66f.fsf@oc8242746057.ibm.com Link: https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion Link: https://lore.kernel.org/bpf/20230701171447.56464-1-sj@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19kcsan: Don't expect 64 bits atomic builtins from 32 bits architecturesChristophe Leroy
[ Upstream commit 353e7300a1db928e427462f2745f9a2cd1625b3d ] Activating KCSAN on a 32 bits architecture leads to the following link-time failure: LD .tmp_vmlinux.kallsyms1 powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_load': kernel/kcsan/core.c:1273: undefined reference to `__atomic_load_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_store': kernel/kcsan/core.c:1273: undefined reference to `__atomic_store_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_exchange': kernel/kcsan/core.c:1273: undefined reference to `__atomic_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_add': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_add_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_sub': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_sub_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_and': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_and_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_or': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_or_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_xor': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_xor_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_nand': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_nand_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_strong': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_weak': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_val': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' 32 bits architectures don't have 64 bits atomic builtins. Only include DEFINE_TSAN_ATOMIC_OPS(64) on 64 bits architectures. Fixes: 0f8ad5f2e934 ("kcsan: Add support for atomic builtins") Suggested-by: Marco Elver <elver@google.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/d9c6afc28d0855240171a4e0ad9ffcdb9d07fceb.1683892665.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe failsDouglas Anderson
[ Upstream commit 9ec272c586b07d1abf73438524bd12b1df9c5f9b ] Patch series "watchdog: Cleanup / fixes after buddy series v5 reviews". This patch series attempts to finish resolving the feedback received from Petr Mladek on the v5 series I posted. Probably the only thing that wasn't fully as clean as Petr requested was the Kconfig stuff. I couldn't find a better way to express it without a more major overhaul. In the very least, I renamed "NON_ARCH" to "PERF_OR_BUDDY" in the hopes that will make it marginally better. Nothing in this series is terribly critical and even the bugfixes are small. However, it does cleanup a few things that were pointed out in review. This patch (of 10): The permissions for the kernel.nmi_watchdog sysctl have always been set at compile time despite the fact that a watchdog can fail to probe. Let's fix this and set the permissions based on whether the hardlockup detector actually probed. Link: https://lkml.kernel.org/r/20230527014153.2793931-1-dianders@chromium.org Link: https://lkml.kernel.org/r/20230526184139.1.I0d75971cc52a7283f495aac0bd5c3041aadc734e@changeid Fixes: a994a3147e4c ("watchdog/hardlockup/perf: Implement init time detection of perf") Signed-off-by: Douglas Anderson <dianders@chromium.org> Reported-by: Petr Mladek <pmladek@suse.com> Closes: https://lore.kernel.org/r/ZHCn4hNxFpY5-9Ki@alley Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/perf: adapt the watchdog_perf interface for async modelLecopzer Chen
[ Upstream commit 930d8f8dbab97cb05dba30e67a2dfa0c6dbf4bc7 ] When lockup_detector_init()->watchdog_hardlockup_probe(), PMU may be not ready yet. E.g. on arm64, PMU is not ready until device_initcall(armv8_pmu_driver_init). And it is deeply integrated with the driver model and cpuhp. Hence it is hard to push this initialization before smp_init(). But it is easy to take an opposite approach and try to initialize the watchdog once again later. The delayed probe is called using workqueues. It need to allocate memory and must be proceed in a normal context. The delayed probe is able to use if watchdog_hardlockup_probe() returns non-zero which means the return code returned when PMU is not ready yet. Provide an API - lockup_detector_retry_init() for anyone who needs to delayed init lockup detector if they had ever failed at lockup_detector_init(). The original assumption is: nobody should use delayed probe after lockup_detector_check() which has __init attribute. That is, anyone uses this API must call between lockup_detector_init() and lockup_detector_check(), and the caller must have __init attribute Link: https://lkml.kernel.org/r/20230519101840.v5.16.If4ad5dd5d09fb1309cebf8bcead4b6a5a7758ca7@changeid Reviewed-by: Petr Mladek <pmladek@suse.com> Co-developed-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Suggested-by: Petr Mladek <pmladek@suse.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/hardlockup: rename some "NMI watchdog" constants/functionDouglas Anderson
[ Upstream commit df95d3085caa5b99a60eb033d7ad6c2ff2b43dbf ] Do a search and replace of: - NMI_WATCHDOG_ENABLED => WATCHDOG_HARDLOCKUP_ENABLED - SOFT_WATCHDOG_ENABLED => WATCHDOG_SOFTOCKUP_ENABLED - watchdog_nmi_ => watchdog_hardlockup_ - nmi_watchdog_available => watchdog_hardlockup_available - nmi_watchdog_user_enabled => watchdog_hardlockup_user_enabled - soft_watchdog_user_enabled => watchdog_softlockup_user_enabled - NMI_WATCHDOG_DEFAULT => WATCHDOG_HARDLOCKUP_DEFAULT Then update a few comments near where names were changed. This is specifically to make it less confusing when we want to introduce the buddy hardlockup detector, which isn't using NMIs. As part of this, we sanitized a few names for consistency. [trix@redhat.com: make variables static] Link: https://lkml.kernel.org/r/20230525162822.1.I0fb41d138d158c9230573eaa37dc56afa2fb14ee@changeid Link: https://lkml.kernel.org/r/20230519101840.v5.12.I91f7277bab4bf8c0cb238732ed92e7ce7bbd71a6@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Tom Rix <trix@redhat.com> Reviewed-by: Tom Rix <trix@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/hardlockup: move perf hardlockup checking/panic to common watchdog.cDouglas Anderson
[ Upstream commit 81972551df9d168a8183b786ff4de06008469c2e ] The perf hardlockup detector works by looking at interrupt counts and seeing if they change from run to run. The interrupt counts are managed by the common watchdog code via its watchdog_timer_fn(). Currently the API between the perf detector and the common code is a function: is_hardlockup(). When the hard lockup detector sees that function return true then it handles printing out debug info and inducing a panic if necessary. Let's change the API a little bit in preparation for the buddy hardlockup detector. The buddy hardlockup detector wants to print nearly the same debug info and have nearly the same panic behavior. That means we want to move all that code to the common file. For now, the code in the common file will only be there if the perf hardlockup detector is enabled, but eventually it will be selected by a common config. Right now, this _just_ moves the code from the perf detector file to the common file and changes the names. It doesn't make the changes that the buddy hardlockup detector will need and doesn't do any style cleanups. A future patch will do cleanup to make it more obvious what changed. With the above, we no longer have any callers of is_hardlockup() outside of the "watchdog.c" file, so we can remove it from the header, make it static, and move it to the same "#ifdef" block as our new watchdog_hardlockup_check(). While doing this, it can be noted that even if no hardlockup detectors were configured the existing code used to still have the code for counting/checking "hrtimer_interrupts" even if the perf hardlockup detector wasn't configured. We didn't need to do that, so move all the "hrtimer_interrupts" counting to only be there if the perf hardlockup detector is configured as well. This change is expected to be a no-op. Link: https://lkml.kernel.org/r/20230519101840.v5.8.Id4133d3183e798122dc3b6205e7852601f289071@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/hardlockup: change watchdog_nmi_enable() to voidLecopzer Chen
[ Upstream commit 730211182ed083898fa5feb4b28459ffac4c9615 ] Nobody cares about the return value of watchdog_nmi_enable(), changing its prototype to void. Link: https://lkml.kernel.org/r/20230519101840.v5.4.Ic3a19b592eb1ac4c6f6eade44ffd943e8637b6e5@changeid Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog: remove WATCHDOG_DEFAULTLecopzer Chen
[ Upstream commit 810b560e8985725dbd57bbb3f188c231365eb5ae ] No reference to WATCHDOG_DEFAULT, remove it. Link: https://lkml.kernel.org/r/20230519101840.v5.3.I6a729209a1320e0ad212176e250ff945b8f91b2a@changeid Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 9ec272c586b0 ("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Verify scalar ids mapping in regsafe() using check_ids()Eduard Zingerman
[ Upstream commit 1ffc85d9298e0ca0137ba65c93a786143fe167b8 ] Make sure that the following unsafe example is rejected by verifier: 1: r9 = ... some pointer with range X ... 2: r6 = ... unbound scalar ID=a ... 3: r7 = ... unbound scalar ID=b ... 4: if (r6 > r7) goto +1 5: r6 = r7 6: if (r6 > X) goto ...
2023-07-19bpf: Use scalar ids in mark_chain_precision()Eduard Zingerman
[ Upstream commit 904e6ddf4133c52fdb9654c2cd2ad90f320d48b9 ] Change mark_chain_precision() to track precision in situations like below: r2 = unknown value ... --- state #0 --- ... r1 = r2 // r1 and r2 now share the same ID ... --- state #1 {r1.id = A, r2.id = A} --- ... if (r2 > 10) goto exit; // find_equal_scalars() assigns range to r1 ... --- state #2 {r1.id = A, r2.id = A} --- r3 = r10 r3 += r1 // need to mark both r1 and r2 At the beginning of the processing of each state, ensure that if a register with a scalar ID is marked as precise, all registers sharing this ID are also marked as precise. This property would be used by a follow-up change in regsafe(). Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230613153824.3324830-2-eddyz87@gmail.com Stable-dep-of: 1ffc85d9298e ("bpf: Verify scalar ids mapping in regsafe() using check_ids()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19kexec: fix a memory leak in crash_shrink_memory()Zhen Lei
[ Upstream commit 1cba6c4309f03de570202c46f03df3f73a0d4c82 ] Patch series "kexec: enable kexec_crash_size to support two crash kernel regions". When crashkernel=X fails to reserve region under 4G, it will fall back to reserve region above 4G and a region of the default size will also be reserved under 4G. Unfortunately, /sys/kernel/kexec_crash_size only supports one crash kernel region now, the user cannot sense the low memory reserved by reading /sys/kernel/kexec_crash_size. Also, low memory cannot be freed by writing this file. For example: resource_size(crashk_res) = 512M resource_size(crashk_low_res) = 256M The result of 'cat /sys/kernel/kexec_crash_size' is 512M, but it should be 768M. When we execute 'echo 0 > /sys/kernel/kexec_crash_size', the size of crashk_res becomes 0 and resource_size(crashk_low_res) is still 256 MB, which is incorrect. Since crashk_res manages the memory with high address and crashk_low_res manages the memory with low address, crashk_low_res is shrunken only when all crashk_res is shrunken. And because when there is only one crash kernel region, crashk_res is always used. Therefore, if all crashk_res is shrunken and crashk_low_res still exists, swap them. This patch (of 6): If the value of parameter 'new_size' is in the semi-open and semi-closed interval (crashk_res.end - KEXEC_CRASH_MEM_ALIGN + 1, crashk_res.end], the calculation result of ram_res is: ram_res->start = crashk_res.end + 1 ram_res->end = crashk_res.end The operation of insert_resource() fails, and ram_res is not added to iomem_resource. As a result, the memory of the control block ram_res is leaked. In fact, on all architectures, the start address and size of crashk_res are already aligned by KEXEC_CRASH_MEM_ALIGN. Therefore, we do not need to round up crashk_res.start again. Instead, we should round up 'new_size' in advance. Link: https://lkml.kernel.org/r/20230527123439.772-1-thunder.leizhen@huawei.com Link: https://lkml.kernel.org/r/20230527123439.772-2-thunder.leizhen@huawei.com Fixes: 6480e5a09237 ("kdump: add missing RAM resource in crash_shrink_memory()") Fixes: 06a7f711246b ("kexec: premit reduction of the reserved memory size") Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Cong Wang <amwang@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19watchdog/perf: more properly prevent false positives with turbo modesDouglas Anderson
[ Upstream commit 4379e59fe5665cfda737e45b8bf2f05321ef049c ] Currently, in the watchdog_overflow_callback() we first check to see if the watchdog had been touched and _then_ we handle the workaround for turbo mode. This order should be reversed. Specifically, "touching" the hardlockup detector's watchdog should avoid lockups being detected for one period that should be roughly the same regardless of whether we're running turbo or not. That means that we should do the extra accounting for turbo _before_ we look at (and clear) the global indicating that we've been touched. NOTE: this fix is made based on code inspection. I am not aware of any reports where the old code would have generated false positives. That being said, this order seems more correct and also makes it easier down the line to share code with the "buddy" hardlockup detector. Link: https://lkml.kernel.org/r/20230519101840.v5.2.I843b0d1de3e096ba111a179f3adb16d576bef5c7@changeid Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with turbo modes") Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Colin Cross <ccross@android.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guenter Roeck <groeck@chromium.org> Cc: Ian Rogers <irogers@google.com> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: Ricardo Neri <ricardo.neri@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: Tzung-Bi Shih <tzungbi@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Make bpf_refcount_acquire fallible for non-owning refsDave Marchevsky
[ Upstream commit 7793fc3babe9fea908e57f7c187ea819f9fd7e95 ] This patch fixes an incorrect assumption made in the original bpf_refcount series [0], specifically that the BPF program calling bpf_refcount_acquire on some node can always guarantee that the node is alive. In that series, the patch adding failure behavior to rbtree_add and list_push_{front, back} breaks this assumption for non-owning references. Consider the following program: n = bpf_kptr_xchg(&mapval, NULL); /* skip error checking */ bpf_spin_lock(&l); if(bpf_rbtree_add(&t, &n->rb, less)) { bpf_refcount_acquire(n); /* Failed to add, do something else with the node */ } bpf_spin_unlock(&l); It's incorrect to assume that bpf_refcount_acquire will always succeed in this scenario. bpf_refcount_acquire is being called in a critical section here, but the lock being held is associated with rbtree t, which isn't necessarily the lock associated with the tree that the node is already in. So after bpf_rbtree_add fails to add the node and calls bpf_obj_drop in it, the program has no ownership of the node's lifetime. Therefore the node's refcount can be decr'd to 0 at any time after the failing rbtree_add. If this happens before the refcount_acquire above, the node might be free'd, and regardless refcount_acquire will be incrementing a 0 refcount. Later patches in the series exercise this scenario, resulting in the expected complaint from the kernel (without this patch's changes): refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 207 at lib/refcount.c:25 refcount_warn_saturate+0xbc/0x110 Modules linked in: bpf_testmod(O) CPU: 1 PID: 207 Comm: test_progs Tainted: G O 6.3.0-rc7-02231-g723de1a718a2-dirty #371 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:refcount_warn_saturate+0xbc/0x110 Code: 6f 64 f6 02 01 e8 84 a3 5c ff 0f 0b eb 9d 80 3d 5e 64 f6 02 00 75 94 48 c7 c7 e0 13 d2 82 c6 05 4e 64 f6 02 01 e8 64 a3 5c ff <0f> 0b e9 7a ff ff ff 80 3d 38 64 f6 02 00 0f 85 6d ff ff ff 48 c7 RSP: 0018:ffff88810b9179b0 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000202 RSI: 0000000000000008 RDI: ffffffff857c3680 RBP: ffff88810027d3c0 R08: ffffffff8125f2a4 R09: ffff88810b9176e7 R10: ffffed1021722edc R11: 746e756f63666572 R12: ffff88810027d388 R13: ffff88810027d3c0 R14: ffffc900005fe030 R15: ffffc900005fe048 FS: 00007fee0584a700(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005634a96f6c58 CR3: 0000000108ce9002 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> bpf_refcount_acquire_impl+0xb5/0xc0 (rest of output snipped) The patch addresses this by changing bpf_refcount_acquire_impl to use refcount_inc_not_zero instead of refcount_inc and marking bpf_refcount_acquire KF_RET_NULL. For owning references, though, we know the above scenario is not possible and thus that bpf_refcount_acquire will always succeed. Some verifier bookkeeping is added to track "is input owning ref?" for bpf_refcount_acquire calls and return false from is_kfunc_ret_null for bpf_refcount_acquire on owning refs despite it being marked KF_RET_NULL. Existing selftests using bpf_refcount_acquire are modified where necessary to NULL-check its return value. [0]: https://lore.kernel.org/bpf/20230415201811.343116-1-davemarchevsky@fb.com/ Fixes: d2dcc67df910 ("bpf: Migrate bpf_rbtree_add and bpf_list_push_{front,back} to possibly fail") Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230602022647.1571784-5-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Fix __bpf_{list,rbtree}_add's beginning-of-node calculationDave Marchevsky
[ Upstream commit cc0d76cafebbd3e1ffab9c4252d48ecc9e0737f6 ] Given the pointer to struct bpf_{rb,list}_node within a local kptr and the byte offset of that field within the kptr struct, the calculation changed by this patch is meant to find the beginning of the kptr so that it can be passed to bpf_obj_drop. Unfortunately instead of doing ptr_to_kptr = ptr_to_node_field - offset_bytes the calculation is erroneously doing ptr_to_ktpr = ptr_to_node_field - (offset_bytes * sizeof(struct bpf_rb_node)) or the bpf_list_node equivalent. This patch fixes the calculation. Fixes: d2dcc67df910 ("bpf: Migrate bpf_rbtree_add and bpf_list_push_{front,back} to possibly fail") Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230602022647.1571784-4-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Set kptr_struct_meta for node param to list and rbtree insert funcsDave Marchevsky
[ Upstream commit 2140a6e3422de22e6ebe77d4d18b6c0c9c425426 ] In verifier.c, fixup_kfunc_call uses struct bpf_insn_aux_data's kptr_struct_meta field to pass information about local kptr types to various helpers and kfuncs at runtime. The recent bpf_refcount series added a few functions to the set that need this information: * bpf_refcount_acquire * Needs to know where the refcount field is in order to increment * Graph collection insert kfuncs: bpf_rbtree_add, bpf_list_push_{front,back} * Were migrated to possibly fail by the bpf_refcount series. If insert fails, the input node is bpf_obj_drop'd. bpf_obj_drop needs the kptr_struct_meta in order to decr refcount and properly free special fields. Unfortunately the verifier handling of collection insert kfuncs was not modified to actually populate kptr_struct_meta. Accordingly, when the node input to those kfuncs is passed to bpf_obj_drop, it is done so without the information necessary to decr refcount. This patch fixes the issue by populating kptr_struct_meta for those kfuncs. Fixes: d2dcc67df910 ("bpf: Migrate bpf_rbtree_add and bpf_list_push_{front,back} to possibly fail") Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230602022647.1571784-3-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Remove anonymous union in bpf_kfunc_call_arg_metaDave Marchevsky
[ Upstream commit 4d585f48ee6b38c54c075b151c5efd2ff65f8ffd ] For kfuncs like bpf_obj_drop and bpf_refcount_acquire - which take user-defined types as input - the verifier needs to track the specific type passed in when checking a particular kfunc call. This requires tracking (btf, btf_id) tuple. In commit 7c50b1cb76ac ("bpf: Add bpf_refcount_acquire kfunc") I added an anonymous union with inner structs named after the specific kfuncs tracking this information, with the goal of making it more obvious which kfunc this data was being tracked / expected to be tracked on behalf of. In a recent series adding a new user of this tuple, Alexei mentioned that he didn't like this union usage as it doesn't really help with readability or bug-proofing ([0]). In an offline convo we agreed to have the tuple be fields (arg_btf, arg_btf_id), with comments in bpf_kfunc_call_arg_meta definition enumerating the uses of the fields by kfunc-specific handling logic. Such a pattern is used by struct bpf_reg_state without trouble. Accordingly, this patch removes the anonymous union in favor of arg_btf and arg_btf_id fields and comment enumerating their current uses. The patch also removes struct btf_and_id, which was only being used by the removed union's inner structs. This is a mechanical change, existing linked_list and rbtree tests will validate that correct (btf, btf_id) are being passed. [0]: https://lore.kernel.org/bpf/20230505021707.vlyiwy57vwxglbka@dhcp-172-26-102-232.dhcp.thefacebook.com Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230510213047.1633612-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: 2140a6e3422d ("bpf: Set kptr_struct_meta for node param to list and rbtree insert funcs") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Fix memleak due to fentry attach failureYafang Shao
[ Upstream commit 108598c39eefbedc9882273ac0df96127a629220 ] If it fails to attach fentry, the allocated bpf trampoline image will be left in the system. That can be verified by checking /proc/kallsyms. This meamleak can be verified by a simple bpf program as follows: SEC("fentry/trap_init") int fentry_run() { return 0; } It will fail to attach trap_init because this function is freed after kernel init, and then we can find the trampoline image is left in the system by checking /proc/kallsyms. $ tail /proc/kallsyms ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf] ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf] $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'" [2522] FUNC 'trap_init' type_id=119 linkage=static $ echo $((6442453466 & 0x7fffffff)) 2522 Note that there are two left bpf trampoline images, that is because the libbpf will fallback to raw tracepoint if -EINVAL is returned. Fixes: e21aa341785c ("bpf: Fix fexit trampoline.") Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <song@kernel.org> Cc: Jiri Olsa <olsajiri@gmail.com> Link: https://lore.kernel.org/bpf/20230515130849.57502-2-laoar.shao@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Remove bpf trampoline selectorYafang Shao
[ Upstream commit 47e79cbeea4b3891ad476047f4c68543eb51c8e0 ] After commit e21aa341785c ("bpf: Fix fexit trampoline."), the selector is only used to indicate how many times the bpf trampoline image are updated and been displayed in the trampoline ksym name. After the trampoline is freed, the selector will start from 0 again. So the selector is a useless value to the user. We can remove it. If the user want to check whether the bpf trampoline image has been updated or not, the user can compare the address. Each time the trampoline image is updated, the address will change consequently. Jiri also pointed out another issue that perf is still using the old name "bpf_trampoline_%lu", so this change can fix the issue in perf. Fixes: e21aa341785c ("bpf: Fix fexit trampoline.") Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <song@kernel.org> Cc: Jiri Olsa <olsajiri@gmail.com> Link: https://lore.kernel.org/bpf/ZFvOOlrmHiY9AgXE@krava Link: https://lore.kernel.org/bpf/20230515130849.57502-3-laoar.shao@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: Don't EFAULT for {g,s}setsockopt with wrong optlenStanislav Fomichev
[ Upstream commit 29ebbba7d46136cba324264e513a1e964ca16c0a ] With the way the hooks implemented right now, we have a special condition: optval larger than PAGE_SIZE will expose only first 4k into BPF; any modifications to the optval are ignored. If the BPF program doesn't handle this condition by resetting optlen to 0, the userspace will get EFAULT. The intention of the EFAULT was to make it apparent to the developers that the program is doing something wrong. However, this inadvertently might affect production workloads with the BPF programs that are not too careful (i.e., returning EFAULT for perfectly valid setsockopt/getsockopt calls). Let's try to minimize the chance of BPF program screwing up userspace by ignoring the output of those BPF programs (instead of returning EFAULT to the userspace). pr_info_once those cases to the dmesg to help with figuring out what's going wrong. Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Suggested-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230511170456.1759459-2-sdf@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: fix propagate_precision() logic for inner framesAndrii Nakryiko
[ Upstream commit f655badf2a8fc028433d9583bf86a6b473721f09 ] Fix propagate_precision() logic to perform propagation of all necessary registers and stack slots across all active frames *in one batch step*. Doing this for each register/slot in each individual frame is wasteful, but the main problem is that backtracking of instruction in any frame except the deepest one just doesn't work. This is due to backtracking logic relying on jump history, and available jump history always starts (or ends, depending how you view it) in current frame. So, if prog A (frame #0) called subprog B (frame #1) and we need to propagate precision of, say, register R6 (callee-saved) within frame #0, we actually don't even know where jump history that corresponds to prog A even starts. We'd need to skip subprog part of jump history first to be able to do this. Luckily, with struct backtrack_state and __mark_chain_precision() handling bitmasks tracking/propagation across all active frames at the same time (added in previous patch), propagate_precision() can be both fixed and sped up by setting all the necessary bits across all frames and then performing one __mark_chain_precision() pass. This makes it unnecessary to skip subprog parts of jump history. We also improve logging along the way, to clearly specify which registers' and slots' precision markings are propagated within which frame. Each frame will have dedicated line and all registers and stack slots from that frame will be reported in format similar to precision backtrack regs/stack logging. E.g.: frame 1: propagating r1,r2,r3,fp-8,fp-16 frame 0: propagating r3,r9,fp-120 Fixes: 529409ea92d5 ("bpf: propagate precision across all frames, not just the last one") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: maintain bitmasks across all active frames in __mark_chain_precisionAndrii Nakryiko
[ Upstream commit 1ef22b6865a73a8aed36d43375fe8c7b30869326 ] Teach __mark_chain_precision logic to maintain register/stack masks across all active frames when going from child state to parent state. Currently this should be mostly no-op, as precision backtracking usually bails out when encountering subprog entry/exit. It's not very apparent from the diff due to increased indentation, but the logic remains the same, except everything is done on specific `fr` frame index. Calls to bt_clear_reg() and bt_clear_slot() are replaced with frame-specific bt_clear_frame_reg() and bt_clear_frame_slot(), where frame index is passed explicitly, instead of using current frame number. We also adjust logging to emit affected frame number. And we also add better logging of human-readable register and stack slot masks, similar to previous patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: f655badf2a8f ("bpf: fix propagate_precision() logic for inner frames") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: improve precision backtrack loggingAndrii Nakryiko
[ Upstream commit d9439c21a9e4769bfd83a03ab39056164d44ac31 ] Add helper to format register and stack masks in more human-readable format. Adjust logging a bit during backtrack propagation and especially during forcing precision fallback logic to make it clearer what's going on (with log_level=2, of course), and also start reporting affected frame depth. This is in preparation for having more than one active frame later when precision propagation between subprog calls is added. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: f655badf2a8f ("bpf: fix propagate_precision() logic for inner frames") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19bpf: encapsulate precision backtracking bookkeepingAndrii Nakryiko
[ Upstream commit 407958a0e980b9e1842ab87b5a1040521e1e24e9 ] Add struct backtrack_state and straightforward API around it to keep track of register and stack masks used and maintained during precision backtracking process. Having this logic separately allow to keep high-level backtracking algorithm cleaner, but also it sets us up to cleanly keep track of register and stack masks per frame, allowing (with some further logic adjustments) to perform precision backpropagation across multiple frames (i.e., subprog calls). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Stable-dep-of: f655badf2a8f ("bpf: fix propagate_precision() logic for inner frames") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19sched/core: Avoid multiple calling update_rq_clock() in __cfsb_csd_unthrottle()Hao Jia
[ Upstream commit ebb83d84e49b54369b0db67136a5fe1087124dcc ] After commit 8ad075c2eb1f ("sched: Async unthrottling for cfs bandwidth"), we may update the rq clock multiple times in the loop of __cfsb_csd_unthrottle(). A prior (although less common) instance of this problem exists in unthrottle_offline_cfs_rqs(). Cure both by ensuring update_rq_clock() is called before the loop and setting RQCF_ACT_SKIP during the loop, to supress further updates. The alternative would be pulling update_rq_clock() out of unthrottle_cfs_rq(), but that gives an even bigger mess. Fixes: 8ad075c2eb1f ("sched: Async unthrottling for cfs bandwidth") Reviewed-By: Ben Segall <bsegall@google.com> Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/20230613082012.49615-4-jiahao.os@bytedance.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscaleQiuxu Zhuo
[ Upstream commit 23fc8df26dead16687ae6eb47b0561a4a832e2f6 ] Running the 'kfree_rcu_test' test case [1] results in a splat [2]. The root cause is the kfree_scale_thread thread(s) continue running after unloading the rcuscale module. This commit fixes that isue by invoking kfree_scale_cleanup() from rcu_scale_cleanup() when removing the rcuscale module. [1] modprobe rcuscale kfree_rcu_test=1 // After some time rmmod rcuscale rmmod torture [2] BUG: unable to handle page fault for address: ffffffffc0601a87 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 11de4f067 P4D 11de4f067 PUD 11de51067 PMD 112f4d067 PTE 0 Oops: 0010 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 1798 Comm: kfree_scale_thr Not tainted 6.3.0-rc1-rcu+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:0xffffffffc0601a87 Code: Unable to access opcode bytes at 0xffffffffc0601a5d. RSP: 0018:ffffb25bc2e57e18 EFLAGS: 00010297 RAX: 0000000000000000 RBX: ffffffffc061f0b6 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff962fd0de RDI: ffffffff962fd0de RBP: ffffb25bc2e57ea8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 000000000000000a R15: 00000000001c1dbe FS: 0000000000000000(0000) GS:ffff921fa2200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc0601a5d CR3: 000000011de4c006 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? kvfree_call_rcu+0xf0/0x3a0 ? kthread+0xf3/0x120 ? kthread_complete_and_exit+0x20/0x20 ? ret_from_fork+0x1f/0x30 </TASK> Modules linked in: rfkill sunrpc ... [last unloaded: torture] CR2: ffffffffc0601a87 ---[ end trace 0000000000000000 ]--- Fixes: e6e78b004fa7 ("rcuperf: Add kfree_rcu() performance Tests") Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19rcu/rcuscale: Move rcu_scale_*() after kfree_scale_cleanup()Qiuxu Zhuo
[ Upstream commit bf5ddd736509a7d9077c0b6793e6f0852214dbea ] This code-movement-only commit moves the rcu_scale_cleanup() and rcu_scale_shutdown() functions to follow kfree_scale_cleanup(). This is code movement is in preparation for a bug-fix patch that invokes kfree_scale_cleanup() from rcu_scale_cleanup(). Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Stable-dep-of: 23fc8df26dea ("rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19rcu-tasks: Stop rcu_tasks_invoke_cbs() from using never-onlined CPUsPaul E. McKenney
[ Upstream commit 401b0de3ae4fa49d1014c8941e26d9a25f37e7cf ] The rcu_tasks_invoke_cbs() function relies on queue_work_on() to silently fall back to WORK_CPU_UNBOUND when the specified CPU is offline. However, the queue_work_on() function's silent fallback mechanism relies on that CPU having been online at some time in the past. When queue_work_on() is passed a CPU that has never been online, workqueue lockups ensue, which can be bad for your kernel's general health and well-being. This commit therefore checks whether a given CPU has ever been online, and, if not substitutes WORK_CPU_UNBOUND in the subsequent call to queue_work_on(). Why not simply omit the queue_work_on() call entirely? Because this function is flooding callback-invocation notifications to all CPUs, and must deal with possibilities that include a sparse cpu_possible_mask. This commit also moves the setting of the rcu_data structure's ->beenonline field to rcu_cpu_starting(), which executes on the incoming CPU before that CPU has ever enabled interrupts. This ensures that the required workqueues are present. In addition, because the incoming CPU has not yet enabled its interrupts, there cannot yet have been any softirq handlers running on this CPU, which means that the WARN_ON_ONCE(!rdp->beenonline) within the RCU_SOFTIRQ handler cannot have triggered yet. Fixes: d363f833c6d88 ("rcu-tasks: Use workqueues for multiple rcu_tasks_invoke_cbs() invocations") Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19rcu: Make rcu_cpu_starting() rely on interrupts being disabledPaul E. McKenney
[ Upstream commit 15d44dfa40305da1648de4bf001e91cc63148725 ] Currently, rcu_cpu_starting() is written so that it might be invoked with interrupts enabled. However, it is always called when interrupts are disabled, either by rcu_init(), notify_cpu_starting(), or from a call point prior to the call to notify_cpu_starting(). But why bother requiring that interrupts be disabled? The purpose is to allow the rcu_data structure's ->beenonline flag to be set after all early processing has completed for the incoming CPU, thus allowing this flag to be used to determine when workqueues have been set up for the incoming CPU, while still allowing this flag to be used as a diagnostic within rcu_core(). This commit therefore makes rcu_cpu_starting() rely on interrupts being disabled. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Stable-dep-of: 401b0de3ae4f ("rcu-tasks: Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19tick/rcu: Fix bogus ratelimit conditionWen Yang
[ Upstream commit a7e282c77785c7eabf98836431b1f029481085ad ] The ratelimit logic in report_idle_softirq() is broken because the exit condition is always true: static int ratelimit; if (ratelimit < 10) return false; ---> always returns here ratelimit++; ---> no chance to run Make it check for >= 10 instead. Fixes: 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") Signed-off-by: Wen Yang <wenyang.linux@foxmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@qq.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19posix-timers: Prevent RT livelock in itimer_delete()Thomas Gleixner
[ Upstream commit 9d9e522010eb5685d8b53e8a24320653d9d4cbbf ] itimer_delete() has a retry loop when the timer is concurrently expired. On non-RT kernels this just spin-waits until the timer callback has completed, except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK enabled. In that case and on RT kernels the existing task could live lock when preempting the task which does the timer delivery. Replace spin_unlock() with an invocation of timer_wait_running() to handle it the same way as the other retry loops in the posix timer code. Fixes: ec8f954a40da ("posix-timers: Use a callback for cancel synchronization on PREEMPT_RT") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/87v8g7c50d.ffs@tglx Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-11fork: lock VMAs of the parent process when forkingSuren Baghdasaryan
commit fb49c455323ff8319a123dd312be9082c49a23a5 upstream. When forking a child process, the parent write-protects anonymous pages and COW-shares them with the child being forked using copy_present_pte(). We must not take any concurrent page faults on the source vma's as they are being processed, as we expect both the vma and the pte's behind it to be stable. For example, the anon_vma_fork() expects the parents vma->anon_vma to not change during the vma copy. A concurrent page fault on a page newly marked read-only by the page copy might trigger wp_page_copy() and a anon_vma_prepare(vma) on the source vma, defeating the anon_vma_clone() that wasn't done because the parent vma originally didn't have an anon_vma, but we now might end up copying a pte entry for a page that has one. Before the per-vma lock based changes, the mmap_lock guaranteed exclusion with concurrent page faults. But now we need to do a vma_start_write() to make sure no concurrent faults happen on this vma while it is being processed. This fix can potentially regress some fork-heavy workloads. Kernel build time did not show noticeable regression on a 56-core machine while a stress test mapping 10000 VMAs and forking 5000 times in a tight loop shows ~5% regression. If such fork time regression is unacceptable, disabling CONFIG_PER_VMA_LOCK should restore its performance. Further optimizations are possible if this regression proves to be problematic. Suggested-by: David Hildenbrand <david@redhat.com> Reported-by: Jiri Slaby <jirislaby@kernel.org> Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@kernel.org/ Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com> Closes: https://lore.kernel.org/all/b198d649-f4bf-b971-31d0-e8433ec2a34c@applied-asynchrony.com/ Reported-by: Jacob Young <jacobly.alt@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624 Fixes: 0bff0aaea03e ("x86/mm: try VMA lock-based page fault handling first") Cc: stable@vger.kernel.org Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-23workqueue: clean up WORK_* constant types, clarify maskingLinus Torvalds
Dave Airlie reports that gcc-13.1.1 has started complaining about some of the workqueue code in 32-bit arm builds: kernel/workqueue.c: In function ‘get_work_pwq’: kernel/workqueue.c:713:24: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] 713 | return (void *)(data & WORK_STRUCT_WQ_DATA_MASK); | ^ [ ... a couple of other cases ... ] and while it's not immediately clear exactly why gcc started complaining about it now, I suspect it's some C23-induced enum type handlign fixup in gcc-13 is the cause. Whatever the reason for starting to complain, the code and data types are indeed disgusting enough that the complaint is warranted. The wq code ends up creating various "helper constants" (like that WORK_STRUCT_WQ_DATA_MASK) using an enum type, which is all kinds of confused. The mask needs to be 'unsigned long', not some unspecified enum type. To make matters worse, the actual "mask and cast to a pointer" is repeated a couple of times, and the cast isn't even always done to the right pointer, but - as the error case above - to a 'void *' with then the compiler finishing the job. That's now how we roll in the kernel. So create the masks using the proper types rather than some ambiguous enumeration, and use a nice helper that actually does the type conversion in one well-defined place. Incidentally, this magically makes clang generate better code. That, admittedly, is really just a sign of clang having been seriously confused before, and cleaning up the typing unconfuses the compiler too. Reported-by: Dave Airlie <airlied@gmail.com> Link: https://lore.kernel.org/lkml/CAPM=9twNnV4zMCvrPkw3H-ajZOH-01JVh_kDrxdPYQErz8ZTdA@mail.gmail.com/ Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tejun Heo <tj@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-22Merge tag 'net-6.4-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from ipsec, bpf, mptcp and netfilter. Current release - regressions: - netfilter: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain - eth: mlx5e: - fix scheduling of IPsec ASO query while in atomic - free IRQ rmap and notifier on kernel shutdown Current release - new code bugs: - phy: manual remove LEDs to ensure correct ordering Previous releases - regressions: - mptcp: fix possible divide by zero in recvmsg() - dsa: revert "net: phy: dp83867: perform soft reset and retain established link" Previous releases - always broken: - sched: netem: acquire qdisc lock in netem_change() - bpf: - fix verifier id tracking of scalars on spill - fix NULL dereference on exceptions - accept function names that contain dots - netfilter: disallow element updates of bound anonymous sets - mptcp: ensure listener is unhashed before updating the sk status - xfrm: - add missed call to delete offloaded policies - fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets - selftests: fixes for FIPS mode - dsa: mt7530: fix multiple CPU ports, BPDU and LLDP handling - eth: sfc: use budget for TX completions Misc: - wifi: iwlwifi: add support for SO-F device with PCI id 0x7AF0" * tag 'net-6.4-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (74 commits) revert "net: align SO_RCVMARK required privileges with SO_MARK" net: wwan: iosm: Convert single instance struct member to flexible array sch_netem: acquire qdisc lock in netem_change() selftests: forwarding: Fix race condition in mirror installation wifi: mac80211: report all unusable beacon frames mptcp: ensure listener is unhashed before updating the sk status mptcp: drop legacy code around RX EOF mptcp: consolidate fallback and non fallback state machine mptcp: fix possible list corruption on passive MPJ mptcp: fix possible divide by zero in recvmsg() mptcp: handle correctly disconnect() failures bpf: Force kprobe multi expected_attach_type for kprobe_multi link bpf/btf: Accept function names that contain dots Revert "net: phy: dp83867: perform soft reset and retain established link" net: mdio: fix the wrong parameters netfilter: nf_tables: Fix for deleting base chains with payload netfilter: nfnetlink_osf: fix module autoload netfilter: nf_tables: drop module reference after updating chain netfilter: nf_tables: disallow timeout for anonymous sets netfilter: nf_tables: disallow updates of anonymous sets ...
2023-06-22Merge tag 'cgroup-for-6.4-rc7-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "It's late but here are two bug fixes. Both fix problems which can be severe but are very confined in scope. The risk to most use cases should be minimal. - Fix for an old bug which triggers if a cgroup subsystem is remounted to a different hierarchy while someone is reading its cgroup.procs/tasks file. The risk is pretty low given how seldom cgroup subsystems are moved across hierarchies. - We moved cpus_read_lock() outside of cgroup internal locks a while ago but forgot to update the legacy_freezer leading to lockdep triggers. Fixed" * tag 'cgroup-for-6.4-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Do not corrupt task iteration when rebinding subsystem cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex in freezer_css_{online,offline}()
2023-06-21Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf Daniel Borkmann says: ==================== pull-request: bpf 2023-06-21 We've added 7 non-merge commits during the last 14 day(s) which contain a total of 7 files changed, 181 insertions(+), 15 deletions(-). The main changes are: 1) Fix a verifier id tracking issue with scalars upon spill, from Maxim Mikityanskiy. 2) Fix NULL dereference if an exception is generated while a BPF subprogram is running, from Krister Johansen. 3) Fix a BTF verification failure when compiling kernel with LLVM_IAS=0, from Florent Revest. 4) Fix expected_attach_type enforcement for kprobe_multi link, from Jiri Olsa. 5) Fix a bpf_jit_dump issue for x86_64 to pick the correct JITed image, from Yonghong Song. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Force kprobe multi expected_attach_type for kprobe_multi link bpf/btf: Accept function names that contain dots selftests/bpf: add a test for subprogram extables bpf: ensure main program has an extable bpf: Fix a bpf_jit_dump issue for x86_64 with sysctl bpf_jit_enable. selftests/bpf: Add test cases to assert proper ID tracking on spill bpf: Fix verifier id tracking of scalars on spill ==================== Link: https://lore.kernel.org/r/20230621101116.16122-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-21Merge tag 'timers-urgent-2023-06-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single regression fix for a regression fix: For a long time the tick was aligned to clock MONOTONIC so that the tick event happened at a multiple of nanoseconds per tick starting from clock MONOTONIC = 0. At some point this changed as the refined jiffies clocksource which is used during boot before the TSC or other clocksources becomes usable, was adjusted with a boot offset, so that time 0 is closer to the point where the kernel starts. This broke the assumption in the tick code that when the tick setup happens early on ktime_get() will return a multiple of nanoseconds per tick. As a consequence applications which aligned their periodic execution so that it does not collide with the tick were not longer guaranteed that the tick period starts from time 0. The fix for this regression was to realign the tick when it is initially set up to a multiple of tick periods. That works as long as the underlying tick device supports periodic mode, but breaks under certain conditions when the tick device supports only one shot mode. Depending on the offset, the alignment delta to clock MONOTONIC can get in a range where the minimal programming delta of the underlying clock event device is larger than the calculated delta to the next tick. This results in a boot hang as the tick code tries to play catch up, but as the tick never fires jiffies are not advanced so it keeps trying for ever. Solve this by moving the tick alignement into the NOHZ / HIGHRES enablement code because at that point it is guaranteed that the underlying clocksource is high resolution capable and not longer depending on the tick. This is far before user space starts, so at the point where applications try to align their timers, the old behaviour of the tick happening at a multiple of nanoseconds per tick starting from clock MONOTONIC = 0 is restored" * tag 'timers-urgent-2023-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/common: Align tick period during sched_timer setup
2023-06-21bpf: Force kprobe multi expected_attach_type for kprobe_multi linkJiri Olsa
We currently allow to create perf link for program with expected_attach_type == BPF_TRACE_KPROBE_MULTI. This will cause crash when we call helpers like get_attach_cookie or get_func_ip in such program, because it will call the kprobe_multi's version (current->bpf_ctx context setup) of those helpers while it expects perf_link's current->bpf_ctx context setup. Making sure that we use BPF_TRACE_KPROBE_MULTI expected_attach_type only for programs attaching through kprobe_multi link. Fixes: ca74823c6e16 ("bpf: Add cookie support to programs attached with kprobe multi link") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230618131414.75649-1-jolsa@kernel.org
2023-06-21bpf/btf: Accept function names that contain dotsFlorent Revest
When building a kernel with LLVM=1, LLVM_IAS=0 and CONFIG_KASAN=y, LLVM leaves DWARF tags for the "asan.module_ctor" & co symbols. In turn, pahole creates BTF_KIND_FUNC entries for these and this makes the BTF metadata validation fail because they contain a dot. In a dramatic turn of event, this BTF verification failure can cause the netfilter_bpf initialization to fail, causing netfilter_core to free the netfilter_helper hashmap and netfilter_ftp to trigger a use-after-free. The risk of u-a-f in netfilter will be addressed separately but the existence of "asan.module_ctor" debug info under some build conditions sounds like a good enough reason to accept functions that contain dots in BTF. Although using only LLVM=1 is the recommended way to compile clang-based kernels, users can certainly do LLVM=1, LLVM_IAS=0 as well and we still try to support that combination according to Nick. To clarify: - > v5.10 kernel, LLVM=1 (LLVM_IAS=0 is not the default) is recommended, but user can still have LLVM=1, LLVM_IAS=0 to trigger the issue - <= 5.10 kernel, LLVM=1 (LLVM_IAS=0 is the default) is recommended in which case GNU as will be used Fixes: 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec") Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Cc: Yonghong Song <yhs@meta.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/bpf/20230615145607.3469985-1-revest@chromium.org
2023-06-20Merge tag 'trace-v6.4-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix MAINTAINERS file to point to proper mailing list for rtla and rv The mailing list pointed to linux-trace-devel instead of linux-trace-kernel. The former is for the tracing libraries and the latter is for anything in the Linux kernel tree. The wrong mailing list was used because linux-trace-kernel did not exist when rtla and rv were created. - User events: - Fix matching of dynamic events to their user events When user writes to dynamic_events file, a lookup of the registered dynamic events is made, but there were some cases that a match could be incorrectly made. - Add auto cleanup of user events Have the user events automatically get removed when the last reference (file descriptor) is closed. This was asked for to prevent leaks of user events hanging around needing admins to clean them up. - Add persistent logic (but not let user space use it yet) In some cases, having a persistent user event (one that does not get cleaned up automatically) is useful. But there's still debates about how to expose this to user space. The infrastructure is added, but the API is not. - Update the selftests Update the user event selftests to reflect the above changes" * tag 'trace-v6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/user_events: Document auto-cleanup and remove dyn_event refs selftests/user_events: Adapt dyn_test to non-persist events selftests/user_events: Ensure auto cleanup works as expected tracing/user_events: Add auto cleanup and future persist flag tracing/user_events: Track refcount consistently via put/get tracing/user_events: Store register flags on events tracing/user_events: Remove user_ns walk for groups selftests/user_events: Add perf self-test for empty arguments events selftests/user_events: Clear the events after perf self-test selftests/user_events: Add ftrace self-test for empty arguments events tracing/user_events: Fix the incorrect trace record for empty arguments events tracing: Modify print_fields() for fields output order tracing/user_events: Handle matching arguments that is null from dyn_events tracing/user_events: Prevent same name but different args event tracing/rv/rtla: Update MAINTAINERS file to point to proper mailing list
2023-06-16tick/common: Align tick period during sched_timer setupThomas Gleixner
The tick period is aligned very early while the first clock_event_device is registered. At that point the system runs in periodic mode and switches later to one-shot mode if possible. The next wake-up event is programmed based on the aligned value (tick_next_period) but the delta value, that is used to program the clock_event_device, is computed based on ktime_get(). With the subtracted offset, the device fires earlier than the exact time frame. With a large enough offset the system programs the timer for the next wake-up and the remaining time left is too small to make any boot progress. The system hangs. Move the alignment later to the setup of tick_sched timer. At this point the system switches to oneshot mode and a high resolution clocksource is available. At this point it is safe to align tick_next_period because ktime_get() will now return accurate (not jiffies based) time. [bigeasy: Patch description + testing]. Fixes: e9523a0d81899 ("tick/common: Align tick period with the HZ tick.") Reported-by: Mathias Krause <minipli@grsecurity.net> Reported-by: "Bhatnagar, Rishabh" <risbhat@amazon.com> Suggested-by: Mathias Krause <minipli@grsecurity.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Richard W.M. Jones <rjones@redhat.com> Tested-by: Mathias Krause <minipli@grsecurity.net> Acked-by: SeongJae Park <sj@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/5a56290d-806e-b9a5-f37c-f21958b5a8c0@grsecurity.net Link: https://lore.kernel.org/12c6f9a3-d087-b824-0d05-0d18c9bc1bf3@amazon.com Link: https://lore.kernel.org/r/20230615091830.RxMV2xf_@linutronix.de
2023-06-14tracing/user_events: Add auto cleanup and future persist flagBeau Belgrave
Currently user events need to be manually deleted via the delete IOCTL call or via the dynamic_events file. Most operators and processes wish to have these events auto cleanup when they are no longer used by anything to prevent them piling without manual maintenance. However, some operators may not want this, such as pre-registering events via the dynamic_events tracefs file. Update user_event_put() to attempt an auto delete of the event if it's the last reference. The auto delete must run in a work queue to ensure proper behavior of class->reg() invocations that don't expect the call to go away from underneath them during the unregister. Add work_struct to user_event struct to ensure we can do this reliably. Add a persist flag, that is not yet exposed, to ensure we can toggle between auto-cleanup and leaving the events existing in the future. When a non-zero flag is seen during register, return -EINVAL to ensure ABI is clear for the user processes while we work out the best approach for persistent events. Link: https://lkml.kernel.org/r/20230614163336.5797-4-beaub@linux.microsoft.com Link: https://lore.kernel.org/linux-trace-kernel/20230518093600.3f119d68@rorschach.local.home/ Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Track refcount consistently via put/getBeau Belgrave
Various parts of the code today track user_event's refcnt field directly via a refcount_add/dec. This makes it hard to modify the behavior of the last reference decrement in all code paths consistently. For example, in the future we will auto-delete events upon the last reference going away. This last reference could happen in many places, but we want it to be consistently handled. Add user_event_get() and user_event_put() for the add/dec. Update all places where direct refcounts are being used to utilize these new functions. In each location pass if event_mutex is locked or not. This allows us to drop events automatically in future patches clearly. Ensure when caller states the lock is held, it really is (or is not) held. Link: https://lkml.kernel.org/r/20230614163336.5797-3-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Store register flags on eventsBeau Belgrave
Currently we don't have any available flags for user processes to use to indicate options for user_events. We will soon have a flag to indicate the event should or should not auto-delete once it's not being used by anyone. Add a reg_flags field to user_events and parameters to existing functions to allow for this in future patches. Link: https://lkml.kernel.org/r/20230614163336.5797-2-beaub@linux.microsoft.com Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Remove user_ns walk for groupsBeau Belgrave
During discussions it was suggested that user_ns is not a good place to try to attach a tracing namespace. The current code has stubs to enable that work that are very likely to change and incur a performance cost. Remove the user_ns walk when creating a group and determining the system name to use, since it's unlikely user_ns will be used in the future. Link: https://lore.kernel.org/all/20230601-urenkel-holzofen-cd9403b9cadd@brauner/ Link: https://lore.kernel.org/linux-trace-kernel/20230601224928.301-1-beaub@linux.microsoft.com Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Fix the incorrect trace record for empty arguments eventssunliming
The user_events support events that has empty arguments. But the trace event is discarded and not really committed when the arguments is empty. Fix this by not attempting to copy in zero-length data. Link: https://lkml.kernel.org/r/20230606062027.1008398-2-sunliming@kylinos.cn Acked-by: Beau Belgrave <beaub@linux.microsoft.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: sunliming <sunliming@kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing: Modify print_fields() for fields output ordersunliming
Now the print_fields() print trace event fields in reverse order. Modify it to the positive sequence. Example outputs for a user event: test0 u32 count1; u32 count2 Output before: example-2547 [000] ..... 325.666387: test0: count2=0x2 (2) count1=0x1 (1) Output after: example-2742 [002] ..... 429.769370: test0: count1=0x1 (1) count2=0x2 (2) Link: https://lore.kernel.org/linux-trace-kernel/20230525085232.5096-1-sunliming@kylinos.cn Fixes: 80a76994b2d88 ("tracing: Add "fields" option to show raw trace event fields") Signed-off-by: sunliming <sunliming@kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Handle matching arguments that is null from dyn_eventssunliming
When A registering user event from dyn_events has no argments, it will pass the matching check, regardless of whether there is a user event with the same name and arguments. Add the matching check when the arguments of registering user event is null. Link: https://lore.kernel.org/linux-trace-kernel/20230529065110.303440-1-sunliming@kylinos.cn Signed-off-by: sunliming <sunliming@kylinos.cn> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-14tracing/user_events: Prevent same name but different args eventsunliming
User processes register name_args for events. If the same name but different args event are registered. The trace outputs of second event are printed as the first event. This is incorrect. Return EADDRINUSE back to the user process if the same name but different args event has being registered. Link: https://lore.kernel.org/linux-trace-kernel/20230529032100.286534-1-sunliming@kylinos.cn Signed-off-by: sunliming <sunliming@kylinos.cn> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13bpf: ensure main program has an extableKrister Johansen
When subprograms are in use, the main program is not jit'd after the subprograms because jit_subprogs sets a value for prog->bpf_func upon success. Subsequent calls to the JIT are bypassed when this value is non-NULL. This leads to a situation where the main program and its func[0] counterpart are both in the bpf kallsyms tree, but only func[0] has an extable. Extables are only created during JIT. Now there are two nearly identical program ksym entries in the tree, but only one has an extable. Depending upon how the entries are placed, there's a chance that a fault will call search_extable on the aux with the NULL entry. Since jit_subprogs already copies state from func[0] to the main program, include the extable pointer in this state duplication. Additionally, ensure that the copy of the main program in func[0] is not added to the bpf_prog_kallsyms table. Instead, let the main program get added later in bpf_prog_load(). This ensures there is only a single copy of the main program in the kallsyms table, and that its tag matches the tag observed by tooling like bpftool. Cc: stable@vger.kernel.org Fixes: 1c2a088a6626 ("bpf: x64: add JIT support for multi-function programs") Signed-off-by: Krister Johansen <kjlx@templeofstupid.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/6de9b2f4b4724ef56efbb0339daaa66c8b68b1e7.1686616663.git.kjlx@templeofstupid.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>