Commit Graph

1444588 Commits

Author SHA1 Message Date
Martin Kaiser
e1c19cd376 perf test: Fix "trace summary" test for musl-based systems
The trace summary test calls /bin/true and filters for open, read and
close events. These events are coming from shared library loads.

On a musl system, the loader and libc may point to the same file. true
needs only libc, no further shared libraries are loaded at startup. The
test fails since no open, read and close events are captured.

  root@host:~# ldd /bin/true
	/lib/ld-musl-riscv64.so.1 (0x3fb8882000)
	libc.so => /lib/ld-musl-riscv64.so.1 (0x3fb8882000)

  root@host:~# file /lib/ld-musl-riscv64.so.1
  /lib/ld-musl-riscv64.so.1: symbolic link to /usr/lib/libc.so

  root@host:~# strace -f /bin/true
  execve("/bin/true", ["/bin/true", ...], ... /* 18 vars */) = 1
  set_tid_address(0x3fa1f7bf70)           = 330
  mprotect(0x2ad6b8e000, 12288, PROT_READ) = 0
  exit_group(0)                           = ?
  +++ exited with 0 +++

Run "cat /dev/null" instead of "true". This creates the required events
regardless of the C library and it works for cat from busybox or from
coreutils.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-11 14:16:38 -03:00
Martin Kaiser
9a4a67dddc perf test: Fix sys_enter_openat event test for musl
The "syscalls:sys_enter_openat event fields" test calls

openat(AT_FDCWD, "/etc/passwd", O_RDONLY | O_DIRECTORY)

and verifies that the flags of the captured event are matching.
This fails for musl, where the openat syscall wrapper always adds
O_LARGEFILE.

Update the check to allow for additional flags, the access mode flags
must be unchanged.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-11 14:16:28 -03:00
Martin Kaiser
a4cbd51862 perf test: Fix nanosleep check in the ftrace test
The perf ftrace test case runs:

  perf ftrace profile --graph-opts depth=5 sleep 0.1

and checks that the output contains a *clock_nanosleep function with a
count of 1.

This fails on a risc-v system that uses musl as its C library. musl's
nanosleep syscall wrapper uses either the nanosleep or the
clock_nanosleep syscall.

Filter for sys_*nanosleep to allow both syscalls.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-11 14:15:49 -03:00
Namhyung Kim
8c8f209361 perf build: Remove NO_GTK2 build test
4751bddd3f ("perf tools: Make GTK2 support opt-in") changed GTK2
build to be opt-in.

So NO_GTK2 is meaningless and we need to pass GTK2=1 to enable it.
Let's update the build-test configuration for that.

Also make_no_ui is the same as make_no_slang since NO_GTK2 is no-op.

Let's get rid of it as well.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:07:36 -03:00
Namhyung Kim
53bc032892 perf build: Add -fms-extensions for GEN_VMLINUX_H=1
On my system, `make GEN_VMLINUX_H=1` fails with a lot of error messages
like below:

  ./util/bpf_skel/vmlinux.h:134488:4: error: declaration does not declare anything [-Werror,-Wmissing-declarations]
   134488 |                         struct freelist_counters;
          |                         ^~~~~~~~~~~~~~~~~~~~~~~~
  make[2]: *** [Makefile.perf:1249: linux/tools/perf/util/bpf_skel/.tmp/lock_contention.bpf.o] Error 1

I saw commit 835a507535 ("selftests/bpf: Add -fms-extensions to bpf
build flags") also added the same flags to bpf programs.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:07:05 -03:00
Namhyung Kim
e41cac8617 perf build: Update error message for BUILD_NONDISTRO=1
It should say binutils-dev(el) instead of plain binutils package as it's
mostly installed already and can confuse people like me. :)

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:06:44 -03:00
James Clark
e7ef461784 perf arm_spe: Print remaining IMPDEF event numbers
Any IMPDEF events not printed out from a known core's IMPDEF list or for
a completely unknown core will still not be shown to the user. Fix this
by printing the remaining bits as comma separated raw numbers, e.g.
"IMPDEF:1,2,3,4".

Suggested-by: Al Grant <al.grant@arm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:04:28 -03:00
James Clark
b566a74041 perf arm_spe: Decode Arm N1 IMPDEF events
>From the TRM [1], N1 has one IMPDEF event which isn't covered by the
common list. Add a framework so that more cores can be added in the
future and that the N1 IMPDEF event can be decoded. Also increase the
size of the buffer because we're adding more strings and if it gets
truncated it falls back to a hex dump only.

[1]: https://developer.arm.com/documentation/100616/0401/Statistical-Profiling-Extension/implementation-defined-features-of-SPE

Suggested-by: Al Grant <al.grant@arm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://developer.arm.com/documentation/100616/0401/Statistical-Profiling-Extension/implementation-defined-features-of-SPE
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:03:42 -03:00
James Clark
96b4910c3c perf arm_spe: Turn event name mappings into an array
This is so we can have a single function that prints events and can be
used with multiple mappings from different CPUs. Remove any bit that was
printed so that later we can print out the remaining unknown impdef
bits.

No functional changes intended.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:03:27 -03:00
James Clark
8cf4d17ec7 perf arm_spe: Store MIDR in arm_spe_pkt
The MIDR will affect printing of arm_spe_pkts, so store a copy of it
there. Technically it's constant for each decoder, but there is no
decoder when doing a raw dump, so it has to be stored in every packet.
It will only be used in raw dump mode and not in normal decoding for
now, but to avoid any surprises, set MIDR properly on the decoder too.

Having both the MIDR and the arm_spe_pkt (which has a copy of it) in the
decoder seemed a bit weird, so remove arm_spe_pkt from the decoder. The
packet is only short lived anyway so probably shouldn't have been there
in the first place.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:03:16 -03:00
James Clark
0c7e4d11fb perf arm_spe: Handle missing CPU IDs
Don't call strtol() with a null pointer to avoid undefined behavior.

I'm not sure of the exact scenario for missing CPU IDs but I don't think
it happens in practice. SPE decoding can continue without them with
reduced functionality, but print an error message anyway.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:03:05 -03:00
James Clark
8e32bd775c perf arm_spe: Make a function to get the MIDR
We'll need the MIDR to dump IMPDEF events in the next commits so extract
a function for it.

No functional changes intended.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 22:02:51 -03:00
Thomas Richter
ae15db3e9b perf callchain: Handle multiple address spaces
perf test 'perf inject to convert DWARF callchains to regular ones'
fails on s390. It was introduced with commit 92ea788d2a ("perf
inject: Add --convert-callchain option")

The failure comes the difference in output. Without the inject script to
convert DWARF the callchains is:

 # perf record -F 999 --call-graph dwarf -- perf test -w noploop
 # perf report -i perf.data --stdio --no-children -q \
					 --percent-limit=1 > /tmp/111
 # cat /tmp/111
    99.30%  perf-noploop  perf               [.] noploop
            |
            ---noploop
               run_workload (inlined)
               cmd_test
               run_builtin (inlined)
               handle_internal_command
               run_argv (inlined)
               main
               __libc_start_call_main
               __libc_start_main_impl (inlined)
               _start
 #

With the inject script step the output is:

 # perf inject -i perf.data --convert-callchain -o /tmp/perf-inject-1.out
 # perf report -i /tmp/perf-inject-1.out --stdio --no-children -q \
		--percent-limit=1 > /tmp/222
 # cat /tmp/222
    99.40%  perf-noploop  perf               [.] noploop
            |
            ---noploop
               run_workload (inlined)
               cmd_test
               run_builtin (inlined)
               handle_internal_command
               run_argv (inlined)
               main
               _start
 # diff /tmp/111 /tmp/222
 1c1
 <     99.30%  perf-noploop  perf               [.] noploop
 ---
 >     99.40%  perf-noploop  perf               [.] noploop
 10,11d9
 <                __libc_start_call_main
 <                __libc_start_main_impl (inlined)
 #

The difference are the symbols __libc_start_call_main and
__libc_start_main_impl.

On x86_64, kernel and user space share a single virtual address space,
with the kernel mapped to the upper end of memory. The instruction
pointer value alone is sufficient to distinguish between user space and
kernel space addresses.

This is not true for s390, which uses separate address spaces for user
and kernel.

The same virtual address can be valid in both address spaces, so the
instruction pointer value alone cannot determine whether an address
belongs to the kernel or user space.

Instead, perf must rely on the cpumode metadata derived from the
processor status word (PSW) at sample time.

In function perf_event__convert_sample_callchain() the first part
copies a kernel callchain and context entries, if any.

It then appends additional entries ignoring the address space
architecture. Taking that into account, the symbols at addresses

   0x3ff970348cb __libc_start_call_main
   0x3ff970349c5 __libc_start_main_impl

(located after the kernel address space on s390) are now included.

Output before:

 # perf test 83
 83: perf inject to convert DWARF callchains to regular ones : FAILED!

Output after:
 # perf test 83
 83: perf inject to convert DWARF callchains to regular ones : Ok

Question to Namhyung:

In function perf_event__convert_sample_callchain() just before the
for() loop this patch modifies, the kernel callchain is copied,
see this comment and the next 5 lines:

   /* copy kernel callchain and context entries */

Then why is machine__kernel_ip() needed in the for() loop, when
the kernel entries have been copied just before the loop?

Note: This patch was tested on x86_64 virtual machine and succeeded.

Fixes: 92ea788d2a ("perf inject: Add --convert-callchain option")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:55:12 -03:00
Ian Rogers
31088ccf03 perf debuginfo: Fix libdw API contract violations
Check return value of `dwfl_report_end` during offline initialization.
Validate `dwfl_module_relocation_info` result before passing to `strcmp`
to avoid potential segmentation faults.

Additionally:
 - Fix a file descriptor leak in `debuginfo__init_offline_dwarf()` when
   `dwfl_report_offline()` or subsequent setup calls fail.

Fixes: 6f1b6291cf ("perf tools: Add util/debuginfo.[ch] files")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:52:51 -03:00
Ian Rogers
5aa1941900 perf annotate-data: Fix libdw API contract violations
Check return values of `dwarf_aggregate_size` and `dwarf_formudata`.

Additionally:
 - Avoid `vfprintf` undefined behavior with `NULL` strings by using
   the `die_name()` helper for `dwarf_diename()` in `pr_*` calls.
 - Use `die_get_data_member_location()` (updated to use
   `dwarf_attr_integrate`) to correctly parse location expressions
   for inherited member locations in the fallback path when
   `dwarf_formudata()` fails.

Fixes: 2bc3cf575a ("perf annotate-data: Improve debug message with location info")
Fixes: 4a111cadac ("perf annotate-data: Add member field in the data type")
Fixes: 8b1042c425 ("perf annotate-data: Set bitfield member offset and size properly")
Fixes: fc044c53b9 ("perf annotate-data: Add dso->data_types tree")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:51:59 -03:00
Ian Rogers
9a2ef19b5f perf probe-finder: Fix libdw API contract violations
Check return values of `dwarf_formsdata`, `dwarf_entrypc`,
`dwarf_highpc`, `dwarf_bytesize`, `dwarf_attr`, `dwarf_decl_line`,
`dwarf_getfuncs`, and `dwarf_formref_die`. Validate `dwarf_diename` and
`dwarf_diecu` results to prevent potential crashes. Fix C90 mixed
declarations.

Additionally:
 - Avoid vfprintf undefined behavior with NULL strings by using the
   `die_name()` helper for `dwarf_diename()` in `pr_*` calls,
   including when warning about tail calls.
 - Prevent NULL pointer dereference in `convert_variable_fields()`
   when processing array elements for variables in registers.
 - Fallback to offset 0 in `line_range_search_cb()` instead of
   skipping functions without `DW_AT_decl_line`.
 - Relax `dwarf_getfuncs` error checking in
   `find_probe_point_by_func()` and `find_line_range_by_func()` to
   prevent premature CU search aborts, ensuring robustness against
   corrupted CUs.

Fixes: 66f69b2197 ("perf probe: Support DW_AT_const_value constant value")
Fixes: 3d918a12a1 ("perf probe: Find fentry mcount fuzzed parameter location")
Fixes: bcfc082150 ("perf probe: Remove redundant dwarf functions")
Fixes: 221d061182 ("perf probe: Fix to search local variables in appropriate scope")
Fixes: b55a87ade3 ("perf probe: Remove die() from probe-finder code")
Fixes: 4c85935122 ("perf probe: Support glob wildcards for function name")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:50:56 -03:00
Ian Rogers
9c6d535ddb perf libdw: Fix libdw API contract violations and memory leaks
Check return values of `dwfl_report_end` and `dwfl_module_addrdie`
to prevent using uninitialized stack variables or reporting success on
failure.

Additionally:
 - Ensure `*file` is freed and inline frames are cleared on error in
   `libdw__addr2line()` to prevent memory leaks and duplicated
   callchains when falling back to other unwinders.
 - Use `die_name()` safe wrapper inside the inline function unwinding
   callback (`libdw_a2l_cb`).
 - Refactor `libdw_a2l_cb`'s repeated memory error handling/cleanup
   paths using a cleaner goto control flow.

Fixes: b7a2b011e9 ("perf powerpc: Unify the skip-callchain-idx libdw with that for addr2line")
Fixes: 88c51002d0 ("perf addr2line: Add a libdw implementation")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:49:59 -03:00
Ian Rogers
15f8c22c46 perf libdw: Support DWARF line 0 in inline list
Allow DWARF line 0 in `libdw_a2l_cb()`, as it is a valid
reference for compiler-generated code.

Filter `die_get_call_lineno` error codes (negative values), but
fallback to line 0 if `call_fname` is present to preserve the
caller's filename instead of discarding it entirely.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:49:49 -03:00
Ian Rogers
0e18b5bb7c perf libdw: Fix callchain parent update in ORDER_CALLER mode
Fix the parent srcline lookup in `libdw_a2l_cb()` to target the
correct parent node depending on the callchain order
(ORDER_CALLER/ORDER_CALLEE).

This ensures inline callchains are not corrupted when nest depth > 2.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:49:32 -03:00
Ian Rogers
674dea094e perf srcline: Introduce inline_node__clear_frames()
Introduce inline_node__clear_frames() to clean up partial allocations.
This is a prerequisite for error handling in libdw inline unwinding.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:49:18 -03:00
Ian Rogers
17e9b4243e perf dwarf-aux: Fix libdw API contract violations
Check return values of `dwarf_decl_line` (where non-optional),
`dwarf_getfuncs`, and `dwarf_lineaddr` to prevent using uninitialized
stack variables or incorrectly reporting success on failure.

For the root DIE in `die_walk_lines()`, `dwarf_decl_line` and
`die_get_decl_file` are optional and their failures are handled
gracefully to avoid breaking line walking on valid functions.
Specifically, remove the strict `!decf` (declared file) check that
would prematurely abort line walking on generated or artificial
functions lacking this optional attribute.

Additionally:
 - Add NULL pointer protection for `strcmp()` in `die_walk_lines()`
   when `inf` or `decf` are NULL to prevent crashes on generated
   code.
 - Use `dwarf_attr_integrate` in `die_get_data_member_location` to
   correctly resolve inherited member locations (e.g. via abstract
   origin or specification).

Fixes: 57f95bf5f8 ("perf probe: Show correct statement line number by perf probe -l")
Fixes: 3f4460a28f ("perf probe: Filter out redundant inline-instances")
Fixes: 75186a9b09 ("perf probe: Fix to show lines of sys_ functions correctly")
Fixes: e0d153c690 ("perf-probe: Move dwarf library routines to dwarf-aux.{c, h}")
Fixes: 6243b9dc4c ("perf probe: Move dwarf specific functions to dwarf-aux.c")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:48:45 -03:00
Ian Rogers
d37a546770 perf dwarf-aux: Fix libdw segmentation fault in cu_walk_functions_at
A segmentation fault was observed in `libdw` when running `perf kmem`
with `--page stat` on some workloads. The crash occurred deep inside
`libdw` (specifically in `dwarf_child` and `dwarf_diename`) when
processing DWARF information.

The root cause was improper error handling of `dwarf_getfuncs` in
`die_find_realfunc` and `die_find_tailfunc`.

`dwarf_getfuncs` returns:
 - `0` on success (when all functions have been processed).
 - A positive offset if the callback aborts early (e.g., via
   `DWARF_CB_ABORT` when a match is found).
 - `-1` on error.

The original code used `if (!dwarf_getfuncs(...)) return NULL;`. On
error (`-1`), `!-1` evaluates to `0` (false), bypassing the error
check. Execution then proceeded as if a match was found, returning
uninitialized stack memory (`die_mem`) to the caller
(`cu_walk_functions_at`). When `cu_walk_functions_at` passed this
uninitialized memory to `libdw` via `dwarf_diename`, it caused a
segmentation fault.

Fix this by correcting the error check to `if (dwarf_getfuncs(...) <= 0)`.

Fixes: e0d153c690 ("perf-probe: Move dwarf library routines to dwarf-aux.{c, h}")
Fixes: d4c537e6bf ("perf probe: Ignore tail calls to probed functions")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zecheng Li <zli94@ncsu.edu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-05-05 21:47:32 -03:00
Linus Torvalds
74fe02ce12 Merge tag 'wq-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:

 - Fix devm_alloc_workqueue() passing a va_list as a positional arg to
   the variadic alloc_workqueue() macro, which garbled wq->name and
   skipped lockdep init on the devm path. Fold both noprof entry points
   onto a va_list helper.

   Also, annotate it using __printf(1, 0)

* tag 'wq-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Annotate alloc_workqueue_va() with __printf(1, 0)
  workqueue: fix devm_alloc_workqueue() va_list misuse
2026-05-05 16:09:31 -07:00
Linus Torvalds
11f00074f7 Merge tag 'cgroup-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - During v6.19, cgroup task unlink was moved from do_exit() to after the
   final task switch to satisfy a controller invariant. That left the kernel
   seeing tasks past exit_signals() longer than userspace expected, and
   several v7.0 follow-ups tried to bridge the gap by making rmdir wait for
   the kernel side. None held up.

   The latest is an A-A deadlock when rmdir is invoked by the reaper of
   zombies whose pidns teardown the rmdir itself is waiting on, which
   points at the synchronizing approach being fundamentally wrong.

   Take a different approach: drop the wait, leave rmdir's user-visible
   side returning as soon as cgroup.procs is empty, and defer the css
   percpu_ref kill that drives ->css_offline() until the cgroup is fully
   depopulated.

   Tagged for stable. Somewhat invasive but contained. The hope is that
   fixing forward sticks. If not, the fallback is to revert the entire
   chain and rework on the development branch.

   Note that this doesn't plug a pre-existing analogous race in
   cgroup_apply_control_disable() (controller disable via
   subtree_control). Not a regression. The development branch will do
   the more invasive restructuring needed for that.

 - Documentation update for cgroup-v1 charge-commit section that still
   referenced functions removed when the memcg hugetlb try-commit-cancel
   protocol was retired.

* tag 'cgroup-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  docs: cgroup-v1: Update charge-commit section
  cgroup: Defer css percpu_ref kill on rmdir until cgroup is depopulated
2026-05-05 15:43:32 -07:00
Linus Torvalds
de95ad90fb Merge tag 'sched_ext-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:

 - Fix idle CPU selection returning prev_cpu outside the task's cpus_ptr
   when the BPF caller's allowed mask was wider. Stable backport.

 - Two opposite-direction gaps in scx_task_iter's cgroup-scoped mode
   versus the global mode:

    - Tasks past exit_signals() are filtered by the cgroup walk but kept
      by global. Sub-scheduler enable abort leaked __scx_init_task()
      state. Add a CSS_TASK_ITER_WITH_DEAD flag to cgroup's task
      iterator (scx_task_iter is its only user) and use it.

    - Tasks past sched_ext_dead() are still returned, tripping
      WARN_ON_ONCE() in callers or making them touch torn-down state.
      Mark and skip under the per-task rq lock.

* tag 'sched_ext-for-7.1-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: idle: Recheck prev_cpu after narrowing allowed mask
  sched_ext: Skip past-sched_ext_dead() tasks in scx_task_iter_next_locked()
  cgroup, sched_ext: Include exiting tasks in cgroup iter
2026-05-05 15:22:04 -07:00
Linus Torvalds
50fb0bcc9d Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
 "All in drivers.

  The largest change is the ufs one which has to introduce a new
  function to check the power state before doing the update and the most
  widely encountered one is the obvious change to sg to not use
  GFP_ATOMIC"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: target: iscsi: reject invalid size Extended CDB AHS
  scsi: ufs: core: Fix bRefClkFreq write failure in HS-LSS mode
  scsi: hisi_sas: Fix sparse warnings in prep_ata_v3_hw()
  scsi: pmcraid: Fix typo in comments
  scsi: scsi_dh_alua: Increase default ALUA timeout to maximum spec value
  scsi: smartpqi: Silence a recursive lock warning
  scsi: mpt3sas: Limit NVMe request size to 2 MiB
  scsi: sg: Don't use GFP_ATOMIC in sg_start_req()
  scsi: target: configfs: Bound snprintf() return in tg_pt_gp_members_show()
2026-05-05 14:38:31 -07:00
Linus Torvalds
13ad98eaab Merge tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev
Pull fbdev fixes from Helge Deller:
 "Four small patches for fbdev, of which two are important: One fixes
  the bitmap font generation and the other prevents a possible
  use-after-free in udlfb:

   - Fix rotating fonts by 180 degrees (Thomas Zimmermann)

   - Drop duplicate include of linux/module.h in fb_defio (Chen Ni)

   - Add vm_ops in udlfb to prevent use-after-free (Rajat Gupta)

   - ipu-v3: clean up kernel-doc warnings (Randy Dunlap)"

* tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
  fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free
  lib/fonts: Fix bit position when rotating by 180 degrees
  fbdev: defio: Remove duplicate include of linux/module.h
  fbdev: ipu-v3: clean up kernel-doc warnings
2026-05-05 14:25:44 -07:00
Linus Torvalds
9207d47f96 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma fixes from Jason Gunthorpe:

 - Several error unwind misses on system calls in mlx5, mana, ocrdma,
   vmw_pvrdma, mlx4, and hns

 - More rxe bugs processing network packets

 - User triggerable races in mlx5 when destroying and creating the same
   same object when the FW returns the same object ID

 - Incorrect passing of an IPv6 address through netlink
   RDMA_NL_LS_OP_IP_RESOLVE

 - Add memory ordering for mlx5's lock avoidance pattenr

 - Protect mana from kernel memory overflow

 - Use safe patterns for xarray/radix_tree look up in mlx5 and hns

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (24 commits)
  RDMA/hns: Fix unlocked call to hns_roce_qp_remove()
  RDMA/hns: Fix xarray race in hns_roce_create_qp_common()
  RDMA/hns: Fix xarray race in hns_roce_create_srq()
  RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event()
  RDMA/mlx4: Fix resource leak on error in mlx4_ib_create_srq()
  RDMA/vmw_pvrdma: Fix double free on pvrdma_alloc_ucontext() error path
  RDMA/ocrdma: Don't NULL deref uctx on errors in ocrdma_copy_pd_uresp()
  RDMA/ocrdma: Clarify the mm_head searching
  RDMA/mana: Fix error unwind in mana_ib_create_qp_rss()
  RDMA/mana: Fix mana_destroy_wq_obj() cleanup in mana_ib_create_qp_rss()
  RDMA/mana: Remove user triggerable WARN_ON() in mana_ib_create_qp_rss()
  RDMA/mana: Validate rx_hash_key_len
  RDMA/mlx5: Add missing store/release for lock elision pattern
  RDMA/mlx5: Restore zero-init to mlx5_ib_modify_qp() ucmd
  RDMA/ionic: Fix typo in format string
  RDMA/mlx5: Fix null-ptr-deref in Raw Packet QP creation
  RDMA/core: Fix rereg_mr use-after-free race
  IB/core: Fix IPv6 netlink message size in ib_nl_ip_send_msg()
  RDMA/mlx5: Fix UAF in DCT destroy due to race with create
  RDMA/mlx5: Fix UAF in SRQ destroy due to race with create
  ...
2026-05-05 09:11:52 -07:00
Linus Torvalds
4e38654713 Merge tag 'media/v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fixes from Mauro Carvalho Chehab:

 - rc: ttusbir: fix inverted error logic

 - Venus/Iris fixes:
      - Kconfig cross compile build testing for x86
      - Use-after-free fix for internal buffers
      - dma_free_attrs size fix
      - Switch to hardware mode clocks
      - Use-after-free fix for a concurrency path
      - Fix H265D_MAX_SLICE size for sc7280 devices

 - camoss: fix some clock-related issues

* tag 'media/v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: qcom: camss: avoid format string warning
  media: qcom: camss: Add missing clocks for VFE lite on sa8775p
  media: qcom: camss: Fix csid clock configuration for sa8775p
  media: qcom: camss: Fix csid IRQ offset for sa8775p
  media: qcom: iris: increase H265D_MAX_SLICE to fix H.265 decoding on SC7280
  media: iris: fix use-after-free of fmt_src during MBPF check
  media: iris: switch to hardware mode after firmware boot
  media: iris: Fix dma_free_attrs() size in iris_hfi_queues_init()
  media: iris: Fix use-after-free in iris_release_internal_buffers()
  media: iris: fix QCOM_MDT_LOADER dependency
  media: venus: fix QCOM_MDT_LOADER dependency
2026-05-05 08:45:41 -07:00
Linus Torvalds
a293ec25d5 Merge tag 'linux_kselftest-fixes-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kselftest fixes from Shuah Khan:

 - Fix extra test number increment in ksft_exit_skip() that results in
   incorrect KTAP result

 - Fix regression introduced by addition of explicit constructor orders
   for fixture tests. This addition broke the ordering of those relative
   to non-fixture tests and the reverse-constructor-order detection

* tag 'linux_kselftest-fixes-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: harness: Restore order of test functions
  selftests: kselftest: fix wrong test number in ksft_exit_skip
2026-05-04 16:02:53 -07:00
T.J. Mercier
d8769544bd docs: cgroup-v1: Update charge-commit section
Commit 1d8f136a42 ("memcg/hugetlb: remove memcg hugetlb
try-commit-cancel protocol") removed mem_cgroup_commit_charge() and
mem_cgroup_cancel_charge(), but the docs still refer to those functions.
There is no longer any charge cancellation.

Update the docs to match the code.

Signed-off-by: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-05-04 11:02:12 -10:00
David Carlier
b34c82777a sched_ext: idle: Recheck prev_cpu after narrowing allowed mask
scx_select_cpu_dfl() narrows @allowed to @cpus_allowed & @p->cpus_ptr
when the BPF caller supplies a @cpus_allowed that differs from
@p->cpus_ptr and @p doesn't have full affinity. However,
@is_prev_allowed was computed against the original (wider)
@cpus_allowed, so the prev_cpu fast paths could pick a @prev_cpu that
is in @cpus_allowed but not in @p->cpus_ptr, violating the intended
invariant that the returned CPU is always usable by @p. The kernel
masks this via the SCX_EV_SELECT_CPU_FALLBACK fallback, but the
behavior contradicts the documented contract.

Move the @is_prev_allowed evaluation past the narrowing block so it
tests against the final @allowed mask.

Fixes: ee9a4e9279 ("sched_ext: idle: Properly handle invalid prev_cpu during idle selection")
Cc: stable@vger.kernel.org # v6.16+
Assisted-by: Claude <noreply@anthropic.com>
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-05-04 11:01:04 -10:00
Linus Torvalds
c7e4e4d5f7 Merge tag 'for-linus-7.1-2' of https://github.com/cminyard/linux-ipmi
Pull IPMI fixes from Corey Minyard:
 "Fix a number of issues that came up recently

  The first two fixes are workarounds for buggy IPMI hardware. The
  hardware says it has data for the IPMI driver to read constantly, so
  the driver reads the data constantly, causing any new requests to be
  blocked.

  The first fix was to check for invalid data right when the data was
  read from the device and stop the operation there (there was a later
  check for invalid data, but it could not stop the operation at that
  point). It turned out the device was providing good data, so that
  didn't fix the issue, but it's still a good check.

  The second fix stops fetching this data after a few fetches and allows
  other operations to occur. The driver won't work very well, but at
  least it won't wedge. This seems to fix the issue.

  The third issue is a problem I spotted while working on the previous
  issue where if a certain memory allocation failed the driver would
  stop working.

  The fourth issue is a problem was a missing set to NULL on a PTR_ERR()
  return, introduced in the previous series for 7.1"

* tag 'for-linus-7.1-2' of https://github.com/cminyard/linux-ipmi:
  ipmi:ssif: NULL thread on error
  ipmi:si: Return state to normal if message allocation fails
  ipmi: Add limits to event and receive message requests
  ipmi: Check event message buffer response for bad data
2026-05-04 12:48:30 -07:00
Tejun Heo
ff9eda4ea9 sched_ext: Skip past-sched_ext_dead() tasks in scx_task_iter_next_locked()
scx_task_iter's cgroup-scoped mode can return tasks whose
sched_ext_dead() has already completed: cgroup_task_dead() removes
from cset->tasks after sched_ext_dead() in finish_task_switch() and is
irq-work deferred on PREEMPT_RT. The global mode is fine -
sched_ext_dead() removes from scx_tasks via list_del_init() first.

Callers (sub-sched enable prep/abort/apply, scx_sub_disable(),
scx_fail_parent()) assume returned tasks are still on @sch and trip
WARN_ON_ONCE() or operate on torn-down state otherwise.

Set %SCX_TASK_OFF_TASKS in sched_ext_dead() under @p's rq lock and
have scx_task_iter_next_locked() skip flagged tasks under the same
lock. Setter and reader serialize on the per-task rq lock - no race.

Signed-off-by: Tejun Heo <tj@kernel.org>
2026-05-04 09:06:03 -10:00
Tejun Heo
60f21a2649 cgroup, sched_ext: Include exiting tasks in cgroup iter
a72f73c4dd ("cgroup: Don't expose dead tasks in cgroup") made
css_task_iter_advance() skip exiting tasks so cgroup.procs stays consistent
with waitpid() visibility. Unfortunately, this broke scx_task_iter.

scx_task_iter walks either scx_tasks (global) or a cgroup subtree via
css_task_iter() and the two modes are expected to cover the same set of
tasks. After the above change the cgroup-scoped mode silently skips tasks
past exit_signals() that are still on scx_tasks.

scx_sub_enable_workfn()'s abort path is one of the symptoms: an exiting
SCX_TASK_SUB_INIT task can race past the cgroup iter leaking
__scx_init_task() state. Other iterations share the same gap.

Add CSS_TASK_ITER_WITH_DEAD to opt out of the skip and use it from
scx_task_iter().

Fixes: b0e4c2f8a0 ("sched_ext: Implement cgroup subtree iteration for scx_task_iter")
Reported-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-05-04 09:06:03 -10:00
Tejun Heo
93618edf75 cgroup: Defer css percpu_ref kill on rmdir until cgroup is depopulated
A chain of commits going back to v7.0 reworked rmdir to satisfy the
controller invariant that a subsystem's ->css_offline() must not run while
tasks are still doing kernel-side work in the cgroup.

[1] d245698d72 ("cgroup: Defer task cgroup unlink until after the task is done switching out")
[2] a72f73c4dd ("cgroup: Don't expose dead tasks in cgroup")
[3] 1b164b876c ("cgroup: Wait for dying tasks to leave on rmdir")
[4] 4c56a8ac68 ("cgroup: Fix cgroup_drain_dying() testing the wrong condition")
[5] 13e786b64b ("cgroup: Increment nr_dying_subsys_* from rmdir context")

[1] moved task cset unlink from do_exit() to finish_task_switch() so a
task's cset link drops only after the task has fully stopped scheduling.
That made tasks past exit_signals() linger on cset->tasks until their final
context switch, which led to a series of problems as what userspace expected
to see after rmdir diverged from what the kernel needs to wait for. [2]-[5]
tried to bridge that divergence: [2] filtered the exiting tasks from
cgroup.procs; [3] had rmdir(2) sleep in TASK_UNINTERRUPTIBLE for them; [4]
fixed the wait's condition; [5] made nr_dying_subsys_* visible
synchronously.

The cgroup_drain_dying() wait in [3] turned out to be a dead end. When the
rmdir caller is also the reaper of a zombie that pins a pidns teardown (e.g.
host PID 1 systemd reaping orphan pids that were re-parented to it during
the same teardown), rmdir blocks in TASK_UNINTERRUPTIBLE waiting for those
pids to free, the pids can't free because PID 1 is the reaper and it's stuck
in rmdir, and the system A-A deadlocks. No internal lock ordering breaks
this; the wait itself is the bug.

The css killing side that drove the original reorder, however, can be made
cleanly asynchronous: ->css_offline() is already async, run from
css_killed_work_fn() driven by percpu_ref_kill_and_confirm(). The fix is to
make that chain start only after all tasks have left the cgroup. rmdir's
user-visible side then returns as soon as cgroup.procs and friends are
empty, while ->css_offline() still runs only after the cgroup is fully
drained.

Verified by the original reproducer (pidns teardown + zombie reaper, runs
under vng) which hangs vanilla and succeeds here, and by per-commit
deterministic repros for [2], [3], [4], [5] with a boot parameter that
widens the post-exit_signals() window so each state is reliably reachable.
Some stress tests on top of that.

cgroup_apply_control_disable() has the same shape of pre-existing race:
when a controller is disabled via subtree_control, kill_css() ran
synchronously while tasks past exit_signals() could still be linked to
the cgroup's csets, and ->css_offline() could fire before they drained.
This patch preserves the existing synchronous behavior at that call site
(kill_css_sync() + kill_css_finish() back-to-back) and a follow-up patch
will defer kill_css_finish() there using a per-css trigger.

This seems like the right approach and I don't see problems with it. The
changes are somewhat invasive but not excessively so, so backporting to
-stable should be okay. If something does turn out to be wrong, the fallback
is to revert the entire chain ([1]-[5]) and rework in the development branch
instead.

v2: Pin cgrp across the deferred destroy work with explicit
    cgroup_get()/cgroup_put() around queue_work() and the work_fn. v1
    wasn't actually broken (ordered cgroup_offline_wq + queue_work order
    in cgroup_task_dead() saved it) but the explicit ref removes the
    dependency on those non-obvious invariants. Also note the
    pre-existing cgroup_apply_control_disable() race in the description;
    a follow-up will defer kill_css_finish() there.

Fixes: 1b164b876c ("cgroup: Wait for dying tasks to leave on rmdir")
Cc: stable@vger.kernel.org # v7.0+
Reported-and-tested-by: Martin Pitt <martin@piware.de>
Link: https://lore.kernel.org/all/afHNg2VX2jy9bW7y@piware.de/
Link: https://lore.kernel.org/all/35e0670adb4abeab13da2c321582af9f@kernel.org/
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
2026-05-04 08:52:26 -10:00
Rajat Gupta
8de779dc40 fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free
dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages
to userspace but sets no vm_ops on the VMA. This means the kernel cannot
track active mmaps. When dlfb_realloc_framebuffer() replaces the backing
buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated.
On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages
while userspace PTEs still reference them, resulting in a use-after-free:
the process retains read/write access to freed kernel pages.

Add vm_operations_struct with open/close callbacks that maintain an
atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(),
check mmap_count and return -EBUSY if the buffer is currently mapped,
preventing buffer replacement while userspace holds stale PTEs.

Tested with PoC using dummy_hcd + raw_gadget USB device emulation.

Signed-off-by: Rajat Gupta <rajgupt@qti.qualcomm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
2026-05-04 10:35:55 +02:00
Linus Torvalds
6d35786de2 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
 "Three bug fixes for x86:

   - Check that nEPT/nNPT is enabled in slow flush hypercalls. If it is
     not, the hypercalls can be processed as usual even while running a
     nested guest

   - Fix shadow paging use-after-free due to page tables changing
     outside execution of the guest. A bug that is 16 years old and
     stems from an imprecision in the very first KVM series

   - Scan IRR whenever PID.ON is true, even if PIR is empty, which
     avoids a somewhat rare WARN"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
  KVM: x86: Fix misleading variable names and add more comments for PIR=>IRR flow
  KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty
  KVM: x86: check for nEPT/nNPT in slow flush hypercalls
2026-05-03 15:25:47 -07:00
Linus Torvalds
7fd2df204f Linux 7.1-rc2 v7.1-rc2 2026-05-03 14:21:25 -07:00
Sean Christopherson
0cb2af2ea6 KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
The shadow MMU computes GFNs for direct shadow pages using sp->gfn plus
the SPTE index. This assumption breaks for shadow paging if the guest
page tables are modified between VM entries (similar to commit
aad885e774, "KVM: x86/mmu: Drop/zap existing present SPTE even
when creating an MMIO SPTE", 2026-03-27).  The flow is as follows:

- a PDE is installed for a 2MB mapping, and a page in that area is
  accessed.  KVM creates a kvm_mmu_page consisting of 512 4KB pages;
  the kvm_mmu_page is marked by FNAME(fetch) as direct-mapped because
  the guest's mapping is a huge page (and thus contiguous).

- the PDE mapping is changed from outside the guest.

- the guest accesses another page in the same 2MB area.  KVM installs
  a new leaf SPTE and rmap entry; the SPTE uses the "correct" GFN
  (i.e. based on the new mapping, as changed in the previous step) but
  that GFN is outside of the [sp->gfn, sp->gfn + 511] range; therefore
  the rmap entry cannot be found and removed when the kvm_mmu_page
  is zapped.

- the memslot that covers the first 2MB mapping is deleted, and the
  kvm_mmu_page for the now-invalid GPA is zapped.  However, rmap_remove()
  only looks at the [sp->gfn, sp->gfn + 511] range established in step 1,
  and fails to find the rmap entry that was recorded by step 3.

- any operation that causes an rmap walk for the same page accessed
  by step 3 then walks a stale rmap and dereferences a freed kvm_mmu_page.
  This includes dirty logging or MMU notifier invalidations (e.g., from
  MADV_DONTNEED).

The underlying issue is that KVM's walking of shadow PTEs assumes that
if a SPTE is present when KVM wants to install a non-leaf SPTE, then the
existing kvm_mmu_page must be for the correct gfn.  Because the only way
for the gfn to be wrong is if KVM messed up and failed to zap a SPTE...
which shouldn't happen, but *actually* only happens in response to a
guest write.

That bug dates back literally forever, as even the first version of KVM
assumes that the GFN matches and walks into the "wrong" shadow page.
However, that was only an imprecision until 2032a93d66 ("KVM: MMU:
Don't allocate gfns page for direct mmu pages") came along.

Fix it by checking for a target gfn mismatch and zapping the existing
SPTE.  That way the old SP and rmap entries are gone, KVM installs
the rmap in the right location, and everyone is happy.

Fixes: 2032a93d66 ("KVM: MMU: Don't allocate gfns page for direct mmu pages")
Fixes: 6aa8b732ca ("kvm: userspace interface")
Reported-by: Alexander Bulekov <bkov@amazon.com>
Reported-by: Fred Griffoul <fgriffo@amazon.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20260503201029.106481-1-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:32:53 +02:00
Sean Christopherson
0aec99f9bf KVM: x86: Fix misleading variable names and add more comments for PIR=>IRR flow
Rename kvm_apic_update_irr()'s "irr_updated" and vmx_sync_pir_to_irr()'s
"got_posted_interrupt" to a more accurate "max_irr_is_from_pir", as neither
"irr_updated" nor "got_posted_interrupt" is accurate.
__kvm_apic_update_irr() and thus kvm_apic_update_irr() specifically return
true if and only if the highest priority IRQ, i.e. max_irr, is a "new"
pending IRQ from the PIR.  I.e. it's possible for the IRR to be updated,
i.e. for a posted IRQ to be "got", *without* the APIs returning true.

Expand vmx_sync_pir_to_irr()'s comment to explain why it's necessary to
set KVM_REQ_EVENT only if a "new" IRQ was found, and to explain why it's
safe to do so only if a new IRQ is also the highest priority pending IRQ.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20260503201703.108231-3-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:32:41 +02:00
Paolo Bonzini
33fd0ccd25 KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty
Fall back to apic_find_highest_vector() when PID.ON is set but PIR
turns out to be empty, to correctly report the highest pending interrupt
from the existing IRR.

In a nested VM stress test, the following WARNING fires in
vmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending
interrupt but the subsequent kvm_apic_has_interrupt() (which invokes
vmx_sync_pir_to_irr() again) returns -1:

  WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events+0x6bf/0x6e0 [kvm_intel]
  Call Trace:
   kvm_check_and_inject_events
   vcpu_enter_guest.constprop.0
   vcpu_run
   kvm_arch_vcpu_ioctl_run
   kvm_vcpu_ioctl
   __x64_sys_ioctl
   do_syscall_64
   entry_SYSCALL_64_after_hwframe

The root cause is a race between vmx_sync_pir_to_irr() on the target vCPU
and __vmx_deliver_posted_interrupt() on a sender vCPU.  The sender
performs two individually-atomic operations that are not a single
transaction:

  1. pi_test_and_set_pir(vector)  -- sets the PIR bit
  2. pi_test_and_set_on()         -- sets PID.ON

The following interleaving triggers the bug:

  Sender vCPU (IPI):              Target vCPU (1st sync_pir_to_irr):
  B1: set PIR[vector]
                                  A1: pi_clear_on()
                                  A2: pi_harvest_pir() -> sees B1 bit
                                  A3: xchg() -> consumes bit, PIR=0
                                      (1st sync returns correct max_irr)
  B2: set PID.ON = 1

                                  Target vCPU (2nd sync_pir_to_irr):
                                  C1: pi_test_on() -> TRUE (from B2)
                                  C2: pi_clear_on() -> ON=0
                                  C3: pi_harvest_pir() -> PIR empty
                                  C4: *max_irr = -1, early return
                                      IRR NOT SCANNED

The interrupt is not lost (it resides in the IRR from the first sync and
is recovered on the next vcpu_enter_guest() iteration), but the incorrect
max_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle.

Fixes: b41f8638b9 ("KVM: VMX: Isolate pure loads from atomic XCHG when processing PIR")
Reported-by: Farrah Chen <farrah.chen@intel.com>
Analyzed-by: Chenyi Qiang <chenyi.qiang@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/20260428070349.1633238-1-chenyi.qiang@intel.com/T/
Link: https://patch.msgid.link/20260503201703.108231-2-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:18:15 +02:00
Paolo Bonzini
464af6fc2b KVM: x86: check for nEPT/nNPT in slow flush hypercalls
Checking is_guest_mode(vcpu) is incorrect, because translate_nested_gpa()
is only valid if an L2 guest is running *with nested EPT/NPT enabled*.
Instead use the same condition as translate_nested_gpa() itself.

Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <seanjc@google.com>
Fixes: aee738236d ("KVM: x86: Prepare kvm_hv_flush_tlb() to handle L2's GPAs", 2022-11-18)
Link: https://patch.msgid.link/20260503200905.106077-1-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2026-05-03 22:17:30 +02:00
Linus Torvalds
f377d0025e Merge tag 'sh-for-v7.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux
Pull sh fix from John Paul Adrian Glaubitz:
 "The ZERO_PAGE consolidation in v7.1, introduced a regression on sh
  which made these systems unbootable.

  The problem was that on sh, the initial boot parameters were
  previously referenced as an array and after 6215d9f447 ("arch, mm:
  consolidate empty_zero_page"), they were referenced as a pointer which
  caused wrong code generation and boot hang.

  This changes the declaration back to being an array which fixes the
  boot hang"

* tag 'sh-for-v7.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux:
  sh: Fix fallout from ZERO_PAGE consolidation
2026-05-03 08:58:42 -07:00
Linus Torvalds
811129272d Merge tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fixes from Vlastimil Babka:

 - Stable fixes for CONFIG_SMP=n where _nolock() allocations in NMI both
   at kmalloc and page allocator levels are not properly protected by
   the spin_trylock() semantics on !SMP (Harry Yoo)

* tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: return NULL early from kmalloc_nolock() in NMI on UP
  mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP
2026-05-03 08:19:57 -07:00
Linus Torvalds
cffcf520fd Merge tag 'locking-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Ingo Molnar:
 "Fix lockup in requeue-PI during signal/timeout wakeups, by Sebastian
  Andrzej Siewior"

* tag 'locking-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Prevent lockup in requeue-PI during signal/ timeout wakeup
2026-05-03 08:17:09 -07:00
Linus Torvalds
c3cba36b39 Merge tag 'sched-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:

 - Fix the delayed dequeue negative lag increase fix in the
   fair scheduler (Peter Zijlstra)

 - Fix wakeup_preempt_fair() to do proper delayed dequeue
   (Vincent Guittot)

 - Clear sched_entity::rel_deadline when initializing
   forked entities, which bug can cause all tasks to be
   EEVDF-ineligible, causing a NULL pointer dereference
   crash in pick_next_entity() (Zicheng Qu)

* tag 'sched-urgent-2026-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Clear rel_deadline when initializing forked entities
  sched/fair: Fix wakeup_preempt_fair() vs delayed dequeue
  sched/fair: Fix the negative lag increase fix
2026-05-03 08:05:23 -07:00
Mike Rapoport (Microsoft)
b0aa5e4b08 sh: Fix fallout from ZERO_PAGE consolidation
Consolidation of empty_zero_page declarations broke boot on sh.

sh stores its initial boot parameters in a page reserved in
arch/sh/kernel/head_32.S. Before commit 6215d9f447 ("arch, mm:
consolidate empty_zero_page") this page was referenced in C code
as an array and after that commit it is referenced as a pointer.

This causes wrong code generation and boot hang.

Declare boot_params_page as an array to fix the issue.

Reported-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Fixes: 6215d9f447 ("arch, mm: consolidate empty_zero_page")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2026-05-03 16:35:40 +02:00
Linus Torvalds
66edb901bf Merge tag 'v7.1-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:

 - Reject algorithms with authsizes that are too short in authencesn

* tag 'v7.1-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: authencesn - reject short ahash digests during instance creation
2026-05-02 12:31:43 -07:00
Linus Torvalds
4c2ed2a3db Merge tag 'ntfs-for-7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/ntfs
Pull ntfs fixes from Namjae Jeon:

 - Fix a NULL pointer dereference in ntfs_index_walk_down() by
   validating index block allocation

 - Fix a memory leak of the symlink target string in
   ntfs_reparse_set_wsl_symlink() during error paths

 - Prevent VCN overflow and validate lowest_vcn in
   ntfs_mapping_pairs_decompress() to avoid runlist corruption

 - Fix a page reference leak in ntfs_write_iomap_end_resident()
   when attribute search context allocation fails

 - Fix an invalid PTR_ERR() usage on a valid folio pointer in
   __ntfs_bitmap_set_bits_in_run()

 - Correct directory link counting by dropping nlink only when
   the MFT record link count reaches zero for WIN32/DOS aliases

 - Fix an uninitialized variable in ntfs_mapping_pairs_decompress()
   by returning an error pointer directly

* tag 'ntfs-for-7.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/ntfs:
  ntfs: Use return instead of goto in ntfs_mapping_pairs_decompress()
  ntfs: drop nlink once for WIN32/DOS aliases
  ntfs: fix invalid PTR_ERR() usage in __ntfs_bitmap_set_bits_in_run()
  ntfs: fix error handling in ntfs_write_iomap_end_resident()
  ntfs: fix VCN overflow in ntfs_mapping_pairs_decompress()
  ntfs: fix WSL symlink target leak on reparse failure
  ntfs: fix NULL dereference in ntfs_index_walk_down()
2026-05-02 12:25:57 -07:00