linux-stable.git/tools, branch v5.4.223

perf auxtrace: Fix address filter symbol name match for modules

2022-11-03T14:56:54+00:00

commit cba04f3136b658583adb191556f99d087589c1cc upstream.

For modules, names from kallsyms__parse() contain the module name which
meant that module symbols did not match exactly by name.

Fix by matching the name string up to the separating tab character.

Fixes: 1b36c03e356936d6 ("perf record: Add support for using symbols in address filters")
Signed-off-by: Adrian Hunter 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221026072736.2982-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

tools: iio: iio_utils: fix digit calculation

2022-11-03T14:56:53+00:00

commit 72b2aa38191bcba28389b0e20bf6b4f15017ff2b upstream.

The iio_utils uses a digit calculation in order to know length of the
file name containing a buffer number. The digit calculation does not
work for number 0.

This leads to allocation of one character too small buffer for the
file-name when file name contains value '0'. (Eg. buffer0).

Fix digit calculation by returning one digit to be present for number
'0'.

Fixes: 096f9b862e60 ("tools:iio:iio_utils: implement digit calculation")
Signed-off-by: Matti Vaittinen 
Link: https://lore.kernel.org/r/Y0f+tKCz+ZAIoroQ@dc75zzyyyyyyyyyyyyycy-3.rev.dnainternet.fi
Cc: 
Signed-off-by: Jonathan Cameron 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc

2022-10-26T11:22:59+00:00

commit 5a3d47071f0ced0431ef82a5fb6bd077ed9493db upstream.

uClibc segfaulted because NULL was passed as the format to fprintf().

That happened because one of the format strings was missing and
intel_pt_print_info() didn't check that before calling fprintf().

Add the missing format string, and check format is not NULL before calling
fprintf().

Fixes: 11fa7cb86b56d361 ("perf tools: Pass Intel PT information for decoding MTC and CYC")
Signed-off-by: Adrian Hunter 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221012082259.22394-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

bpftool: Clear errno after libcap's checks

2022-10-26T11:22:48+00:00

[ Upstream commit cea558855c39b7f1f02ff50dcf701ca6596bc964 ]

When bpftool is linked against libcap, the library runs a "constructor"
function to compute the number of capabilities of the running kernel
[0], at the beginning of the execution of the program. As part of this,
it performs multiple calls to prctl(). Some of these may fail, and set
errno to a non-zero value:

    # strace -e prctl ./bpftool version
    prctl(PR_CAPBSET_READ, CAP_MAC_OVERRIDE) = 1
    prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid argument)
    prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = 1
    prctl(PR_CAPBSET_READ, 0x2c /* CAP_??? */) = -1 EINVAL (Invalid argument)
    prctl(PR_CAPBSET_READ, 0x2a /* CAP_??? */) = -1 EINVAL (Invalid argument)
    prctl(PR_CAPBSET_READ, 0x29 /* CAP_??? */) = -1 EINVAL (Invalid argument)
    ** fprintf added at the top of main(): we have errno == 1
    ./bpftool v7.0.0
    using libbpf v1.0
    features: libbfd, libbpf_strict, skeletons
    +++ exited with 0 +++

This has been addressed in libcap 2.63 [1], but until this version is
available everywhere, we can fix it on bpftool side.

Let's clean errno at the beginning of the main() function, to make sure
that these checks do not interfere with the batch mode, where we error
out if errno is set after a bpftool command.

  [0] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/tree/libcap/cap_alloc.c?h=libcap-2.65#n20
  [1] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=f25a1b7e69f7b33e6afb58b3e38f3450b7d2d9a0

Signed-off-by: Quentin Monnet 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20220815162205.45043-1-quentin@isovalent.com
Signed-off-by: Sasha Levin

bpftool: Fix a wrong type cast in btf_dumper_int

2022-10-26T11:22:22+00:00

[ Upstream commit 7184aef9c0f7a81db8fd18d183ee42481d89bf35 ]

When `data` points to a boolean value, casting it to `int *` is problematic
and could lead to a wrong value being passed to `jsonw_bool`. Change the
cast to `bool *` instead.

Fixes: b12d6ec09730 ("bpf: btf: add btf print functionality")
Signed-off-by: Lam Thai 
Signed-off-by: Andrii Nakryiko 
Reviewed-by: Quentin Monnet 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/20220824225859.9038-1-lamthai@arista.com
Signed-off-by: Sasha Levin

perf tools: Fixup get_current_dir_name() compilation

2022-10-15T05:54:36+00:00

commit 128dbd78bd673f9edbc4413072b23efb6657feb0 upstream.

strdup() prototype doesn't live in stdlib.h .

Add limits.h for PATH_MAX definition as well.

This fixes the build on Android.

Signed-off-by: Alexey Dobriyan (SK hynix) 
Acked-by: Namhyung Kim 
Link: http://lore.kernel.org/lkml/YRukaQbrgDWhiwGr@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

x86/speculation: Add RSB VM Exit protections

2022-10-07T07:16:56+00:00

commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream.

tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as
documented for RET instructions after VM exits. Mitigate it with a new
one-entry RSB stuffing mechanism and a new LFENCE.

== Background ==

Indirect Branch Restricted Speculation (IBRS) was designed to help
mitigate Branch Target Injection and Speculative Store Bypass, i.e.
Spectre, attacks. IBRS prevents software run in less privileged modes
from affecting branch prediction in more privileged modes. IBRS requires
the MSR to be written on every privilege level change.

To overcome some of the performance issues of IBRS, Enhanced IBRS was
introduced.  eIBRS is an "always on" IBRS, in other words, just turn
it on once instead of writing the MSR on every privilege level change.
When eIBRS is enabled, more privileged modes should be protected from
less privileged modes, including protecting VMMs from guests.

== Problem ==

Here's a simplification of how guests are run on Linux' KVM:

void run_kvm_guest(void)
{
	// Prepare to run guest
	VMRESUME();
	// Clean up after guest runs
}

The execution flow for that would look something like this to the
processor:

1. Host-side: call run_kvm_guest()
2. Host-side: VMRESUME
3. Guest runs, does "CALL guest_function"
4. VM exit, host runs again
5. Host might make some "cleanup" function calls
6. Host-side: RET from run_kvm_guest()

Now, when back on the host, there are a couple of possible scenarios of
post-guest activity the host needs to do before executing host code:

* on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not
touched and Linux has to do a 32-entry stuffing.

* on eIBRS hardware, VM exit with IBRS enabled, or restoring the host
IBRS=1 shortly after VM exit, has a documented side effect of flushing
the RSB except in this PBRSB situation where the software needs to stuff
the last RSB entry "by hand".

IOW, with eIBRS supported, host RET instructions should no longer be
influenced by guest behavior after the host retires a single CALL
instruction.

However, if the RET instructions are "unbalanced" with CALLs after a VM
exit as is the RET in #6, it might speculatively use the address for the
instruction after the CALL in #3 as an RSB prediction. This is a problem
since the (untrusted) guest controls this address.

Balanced CALL/RET instruction pairs such as in step #5 are not affected.

== Solution ==

The PBRSB issue affects a wide variety of Intel processors which
support eIBRS. But not all of them need mitigation. Today,
X86_FEATURE_RSB_VMEXIT triggers an RSB filling sequence that mitigates
PBRSB. Systems setting RSB_VMEXIT need no further mitigation - i.e.,
eIBRS systems which enable legacy IBRS explicitly.

However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RSB_VMEXIT
and most of them need a new mitigation.

Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE
which triggers a lighter-weight PBRSB mitigation versus RSB_VMEXIT.

The lighter-weight mitigation performs a CALL instruction which is
immediately followed by a speculative execution barrier (INT3). This
steers speculative execution to the barrier -- just like a retpoline
-- which ensures that speculation can never reach an unbalanced RET.
Then, ensure this CALL is retired before continuing execution with an
LFENCE.

In other words, the window of exposure is opened at VM exit where RET
behavior is troublesome. While the window is open, force RSB predictions
sampling for RET targets to a dead end at the INT3. Close the window
with the LFENCE.

There is a subset of eIBRS systems which are not vulnerable to PBRSB.
Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB.
Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO.

  [ bp: Massage, incorporate review comments from Andy Cooper. ]

Signed-off-by: Daniel Sneddon 
Co-developed-by: Pawan Gupta 
Signed-off-by: Pawan Gupta 
Signed-off-by: Borislav Petkov 
[cascardo: no intra-function validation]
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

Revert "x86/speculation: Add RSB VM Exit protections"

2022-10-07T07:16:54+00:00

This reverts commit f2f41ef0352db9679bfae250d7a44b3113f3a3cc.

This is commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream.

In order to apply IBRS mitigation for Retbleed, PBRSB mitigations must be
reverted and the reapplied, so the backports can look sane.

Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

selftests: Fix the if conditions of in test_extra_filter()

2022-10-05T08:37:45+00:00

[ Upstream commit bc7a319844891746135dc1f34ab9df78d636a3ac ]

The socket 2 bind the addr in use, bind should fail with EADDRINUSE. So
if bind success or errno != EADDRINUSE, testcase should be failed.

Fixes: 3ca8e4029969 ("soreuseport: BPF selection functional test")
Signed-off-by: Wang Yufen 
Link: https://lore.kernel.org/r/1663916557-10730-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

perf kcore_copy: Do not check /proc/modules is unchanged

2022-09-28T09:04:07+00:00

[ Upstream commit 5b427df27b94aec1312cace48a746782a0925c53 ]

/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.

However /proc/modules also might change due to reference counts changing
even though that does not make any difference.

Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.

Remove the comparison checking that /proc/modules is unchanged.

Fixes: fc1b691d7651d949 ("perf buildid-cache: Add ability to add kcore to the cache")
Reported-by: Daniel Dao 
Signed-off-by: Adrian Hunter 
Tested-by: Daniel Dao 
Acked-by: Namhyung Kim 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20220914122429.8770-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin