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Athira Rajeev 341e0e9f59 perf callchain powerpc: Fix addr location init during arch_skip_callchain_idx function
'perf record;  with callchain recording fails as below
in powerpc:

    ./perf record -a -gR sleep 10
    ./perf report
    perf: Segmentation fault

gdb trace points to thread__find_map

    0  0x00000000101df314 in atomic_cmpxchg (newval=1818846826, oldval=1818846827, v=0x1001a8f3) at /home/athira/linux/tools/include/asm-generic/atomic-gcc.h:70
    1  refcount_sub_and_test (i=1, r=0x1001a8f3) at /home/athira/linux/tools/include/linux/refcount.h:135
    2  refcount_dec_and_test (r=0x1001a8f3) at /home/athira/linux/tools/include/linux/refcount.h:148
    3  map__put (map=0x1001a8b3) at util/map.c:311
    4  0x000000001016842c in __map__zput (map=0x7fffffffa368) at util/map.h:190
    5  thread__find_map (thread=0x105b92f0, cpumode=<optimized out>, addr=13835058055283572736, al=al@entry=0x7fffffffa358) at util/event.c:582
    6  0x000000001016882c in thread__find_symbol (thread=<optimized out>, cpumode=<optimized out>, addr=<optimized out>, al=0x7fffffffa358) at util/event.c:656
    7  0x00000000102e12b4 in arch_skip_callchain_idx (thread=<optimized out>, chain=<optimized out>) at arch/powerpc/util/skip-callchain-idx.c:255
    8  0x00000000101d3bf4 in thread__resolve_callchain_sample (thread=0x105b92f0, cursor=0x1053d160, evsel=<optimized out>, sample=0x7fffffffa908, parent=0x7fffffffa778, root_al=0x7fffffffa710,
        max_stack=<optimized out>) at util/machine.c:2940
    9  0x00000000101cd210 in sample__resolve_callchain (sample=<optimized out>, cursor=<optimized out>, parent=<optimized out>, evsel=<optimized out>, al=<optimized out>, max_stack=<optimized out>)
        at util/callchain.c:1112
    10 0x000000001022a9d8 in hist_entry_iter__add (iter=0x7fffffffa750, al=0x7fffffffa710, max_stack_depth=<optimized out>, arg=0x7fffffffbbd0) at util/hist.c:1232
    11 0x0000000010056d98 in process_sample_event (tool=0x7fffffffbbd0, event=0x7ffff6223c38, sample=0x7fffffffa908, evsel=<optimized out>, machine=0x10524ef8) at builtin-report.c:332

Here arch_skip_callchain_idx calls thread__find_symbol and which
invokes thread__find_map with uninitialised "addr_location".
Snippet:

thread__find_symbol(thread, PERF_RECORD_MISC_USER, ip, &al);

Recent change with commit 0dd5041c9a ("perf addr_location: Add
init/exit/copy functions") , introduced "maps__zput" in the function
thread__find_map. This could result in segfault while accessing
uninitialised map from "struct addr_location". Fix this by adding
addr_location__init and addr_location__exit in arch_skip_callchain_idx.

Fixes: 0dd5041c9a ("perf addr_location: Add init/exit/copy functions")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230724165815.17810-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-07-24 17:46:11 -03:00
Documentation Devicetree fixes for v6.5: 2023-07-22 10:28:22 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch ARM: 2023-07-23 10:44:38 -07:00
block block-6.5-2023-07-21 2023-07-22 11:05:15 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
drivers s390 fixes for 6.5-rc3 2023-07-22 11:24:03 -07:00
fs Bug and regression fixes for 6.5-rc3 for ext4's mballoc and jbd2's 2023-07-23 10:21:49 -07:00
include ARM: 2023-07-23 10:44:38 -07:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-21 2023-07-22 10:46:30 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Tracing fixes for 6.5-rc2: 2023-07-23 15:19:14 -07:00
lib block-6.5-2023-07-21 2023-07-22 11:05:15 -07:00
mm mm/mlock: fix vma iterator conversion of apply_vma_lock_flags() 2023-07-17 12:53:21 -07:00
net Including fixes from BPF, netfilter, bluetooth and CAN. 2023-07-20 14:46:39 -07:00
rust rust: error: `impl Debug` for `Error` with `errname()` integration 2023-06-13 01:24:42 +02:00
samples arm64: ftrace: Add direct call trampoline samples support 2023-07-10 17:51:54 -04:00
scripts Kbuild fixes for v6.5 2023-07-23 14:55:41 -07:00
security security: keys: Modify mismatched function name 2023-07-17 19:40:27 +00:00
sound ASoC: Fixes for v6.5 2023-07-20 15:16:11 +02:00
tools perf callchain powerpc: Fix addr location init during arch_skip_callchain_idx function 2023-07-24 17:46:11 -03:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM64: 2023-07-03 15:32:22 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap Including fixes from BPF, netfilter, bluetooth and CAN. 2023-07-20 14:46:39 -07:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ASoC: Fixes for v6.5 2023-07-17 08:21:09 +02:00
Makefile Linux 6.5-rc3 2023-07-23 15:24:10 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.