Pull parisc architecture fixes from Helge Deller: "Fixes CPU hotplug, the parisc stack unwinder and two possible build errors in kprobes and ftrace area: - Fix CPU hotplug - Fix unaligned accesses and faults in stack unwinder - Fix potential build errors by always including asm-generic/kprobes.h - Fix build bug by add missing CONFIG_DYNAMIC_FTRACE check" * tag 'parisc-for-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix stack unwinder parisc/kprobes: always include asm-generic/kprobes.h parisc/ftrace: add missing CONFIG_DYNAMIC_FTRACE check Revert "parisc: Only list existing CPUs in cpu_possible_mask"
Debugging shows a large number of unaligned access traps in the unwinder
code. Code analysis reveals a number of issues with this code:
- handle_interruption is passed twice through
dereference_kernel_function_descriptor()
- ret_from_kernel_thread, syscall_exit, intr_return,
_switch_to_ret, and _call_on_stack are passed through
dereference_kernel_function_descriptor() even though they are
not declared as function pointers.
To fix the problems, drop one of the calls to
dereference_kernel_function_descriptor() for handle_interruption,
and compare the other pointers directly.
Fixes: 6414b30b39f9 ("parisc: unwind: Avoid missing prototype warning for handle_interruption()")
Fixes: 8e0ba125c2bf ("parisc/unwind: fix unwinder when CONFIG_64BIT is enabled")
Cc: Helge Deller <deller@gmx.de>
Cc: Sven Schnelle <svens@stackframe.org>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>
The NOKPROBE_SYMBOL macro (and others) were moved to
asm-generic/kprobes.h in 2017 by commit 7d134b2ce639 ("kprobes: move
kprobe declarations to asm-generic/kprobes.h"), and this new header
was included by asm/kprobes.h unconditionally on all architectures.
When kprobe support was added to parisc in 2017 by commit
8858ac8e9e9b1 ("parisc: Implement kprobes"), that header was only
included when CONFIG_KPROBES was enabled.
This can lead to build failures when NOKPROBE_SYMBOL is used, but
CONFIG_KPROBES is disabled. This mistake however was never actually
noticed because linux/kprobes.h also includes asm-generic/kprobes.h
(though I do not understand why that is, because it also includes
asm/kprobes.h).
To prevent eventual build failures, I suggest to always include
asm-generic/kprobes.h on parisc, just like all the other architectures
do. This way, including asm/kprobes.h suffices, and nobody (outside
of arch/) ever needs to explicitly include asm-generic/kprobes.h.
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes a bug revealed by -Wmissing-prototypes when
CONFIG_FUNCTION_GRAPH_TRACER is enabled but not CONFIG_DYNAMIC_FTRACE:
arch/parisc/kernel/ftrace.c:82:5: error: no previous prototype for 'ftrace_enable_ftrace_graph_caller' [-Werror=missing-prototypes]
82 | int ftrace_enable_ftrace_graph_caller(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/parisc/kernel/ftrace.c:88:5: error: no previous prototype for 'ftrace_disable_ftrace_graph_caller' [-Werror=missing-prototypes]
88 | int ftrace_disable_ftrace_graph_caller(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: Helge Deller <deller@gmx.de>
GNU Make manual [1] clearly forbids a tab at the beginning of the
conditional directive line:
"Extra spaces are allowed and ignored at the beginning of the
conditional directive line, but a tab is not allowed."
This will not work for the next release of GNU Make, hence commit
82175d1f9430 ("kbuild: Replace tabs with spaces when followed by
conditionals") replaced the inappropriate tabs with 8 spaces.
However, the 8-space indentation cannot be visually distinguished.
Linus suggested 2-4 spaces for those nested if-statements. [2]
This commit redoes the replacement with 4 spaces.
[1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax
[2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f53 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").
Then, much later, we ended up removing the workaround in commit
43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.
Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround. But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.
It looks like there are at least two separate issues that all hit in
this area:
(a) some versions of gcc don't mark the asm goto as 'volatile' when it
has outputs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420
which is easy to work around by just adding the 'volatile' by hand.
(b) Internal compiler errors:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422
which are worked around by adding the extra empty 'asm' as a
barrier, as in the original workaround.
but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.
but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.
Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 0921244f6f4f0d05698b953fe632a99b38907226. It broke CPU hotplugging because it modifies the __cpu_possible_mask after bootup, so that it will be different than nr_cpu_ids, which then effictively breaks the workqueue setup code and triggers crashes when shutting down CPUs at runtime. Guenter was the first who noticed the wrong values in __cpu_possible_mask, since the cpumask Kunit tests were failig. Reverting this commit fixes both issues, but sadly brings back this uncritical runtime warning: register_cpu_capacity_sysctl: too early to get CPU4 device! Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lkml.org/lkml/2024/2/4/146 Link: https://lore.kernel.org/lkml/Zb0mbHlIud_bqftx@slm.duckdns.org/t/ Cc: stable@vger.kernel.org # 6.0+
Pull parisc architecture fixes from Helge Deller: "The current exception handler, which helps on kernel accesses to userspace, may exhibit data corruption. The problem is that it is not guaranteed that the compiler will use the processor register we specified in the source code, but may choose another register which then will lead to silent register- and data corruption. To fix this issue we now use another strategy to help the exception handler to always find and set the error code into the correct CPU register. The other fixes are small: fixing CPU hotplug bringup, fix the page alignment of the RO_DATA section, added a check for the calculated cache stride and fix possible hangups when printing longer output at bootup when running on serial console. Most of the patches are tagged for stable series. - Fix random data corruption triggered by exception handler - Fix crash when setting up BTLB at CPU bringup - Prevent hung tasks when printing inventory on serial console - Make RO_DATA page aligned in vmlinux.lds.S - Add check for valid cache stride size" * tag 'parisc-for-6.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: BTLB: Fix crash when setting up BTLB at CPU bringup parisc: Fix random data corruption from exception handler parisc: Drop unneeded semicolon in parse_tree_node() parisc: Prevent hung tasks when printing inventory on serial console parisc: Check for valid stride size for cache flushes parisc: Make RO_DATA page aligned in vmlinux.lds.S
This is needed for the future (post make-4.4.1) versions of gnu make. Starting from https://git.savannah.gnu.org/cgit/make.git/commit/?id=07fcee35f058a876447c8a021f9eb1943f902534 gnu make won't allow conditionals to follow recipe prefix. For example there is a tab followed by ifeq on line 324 in the root Makefile. With the new make this conditional causes the following $ make cpu.o /home/dgoncharov/src/linux-kbuild/Makefile:2063: *** missing 'endif'. Stop. make: *** [Makefile:240: __sub-make] Error 2 This patch replaces tabs followed by conditionals with 8 spaces. See https://savannah.gnu.org/bugs/?64185 and https://savannah.gnu.org/bugs/?64259 for details. Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net> Reported-by: Martin Dorey <martin.dorey@hitachivantara.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When using hotplug and bringing up a 32-bit CPU, ask the firmware about the
BTLB information to set up the static (block) TLB entries.
For that write access to the static btlb_info struct is needed, but
since it is marked __ro_after_init the kernel segfaults with missing
write permissions.
Fix the crash by dropping the __ro_after_init annotation.
Fixes: e5ef93d02d6c ("parisc: BTLB: Initialize BTLB tables at CPU startup")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.6+