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When reading a perf.data file with register values, there is a mismatch
between the names and the values of the registers because the tool is
built using only the register names from the local architecture.
Reading a perf.data file that was recorded on ARM64, gives the following
erroneous output on an X86 machine:
# perf report -i perf_arm64.data -D
[...]
24661932634451 0x698 [0x21d0]: PERF_RECORD_SAMPLE(IP, 0x1): 43239/43239: 0xffffc5be8f100f98 period: 1 addr: 0
... user regs: mask 0x1ffffffff ABI 64-bit
.... AX 0x0000ffffd1515817
.... BX 0x0000ffffd1515480
.... CX 0x0000aaaadabf6c80
.... DX 0x000000000000002e
.... SI 0x0000000040100401
.... DI 0x0040600200000080
.... BP 0x0000ffffd1510e10
.... SP 0x0000000000000000
.... IP 0x00000000000000dd
.... FLAGS 0x0000ffffd1510cd0
.... CS 0x0000000000000000
.... SS 0x0000000000000030
.... DS 0x0000ffffa569a208
.... ES 0x0000000000000000
.... FS 0x0000000000000000
.... GS 0x0000000000000000
.... R8 0x0000aaaad3de9650
.... R9 0x0000ffffa57397f0
.... R10 0x0000000000000001
.... R11 0x0000ffffa57fd000
.... R12 0x0000ffffd1515817
.... R13 0x0000ffffd1515480
.... R14 0x0000aaaadabf6c80
.... R15 0x0000000000000000
.... unknown 0x0000000000000001
.... unknown 0x0000000000000000
.... unknown 0x0000000000000000
.... unknown 0x0000000000000000
.... unknown 0x0000000000000000
.... unknown 0x0000ffffd1510d90
.... unknown 0x0000ffffa5739b90
.... unknown 0x0000ffffd1510d80
.... XMM0 0x0000ffffa57392c8
... thread: perf-exec:43239
...... dso: [kernel.kallsyms]
As can be seen, the register names correspond to X86 registers, even
though the perf.data file was recorded on an ARM64 system. After this
patch, the output of the command displays the correct register names:
# perf report -i perf_arm64.data -D
[...]
24661932634451 0x698 [0x21d0]: PERF_RECORD_SAMPLE(IP, 0x1): 43239/43239: 0xffffc5be8f100f98 period: 1 addr: 0
... user regs: mask 0x1ffffffff ABI 64-bit
.... x0 0x0000ffffd1515817
.... x1 0x0000ffffd1515480
.... x2 0x0000aaaadabf6c80
.... x3 0x000000000000002e
.... x4 0x0000000040100401
.... x5 0x0040600200000080
.... x6 0x0000ffffd1510e10
.... x7 0x0000000000000000
.... x8 0x00000000000000dd
.... x9 0x0000ffffd1510cd0
.... x10 0x0000000000000000
.... x11 0x0000000000000030
.... x12 0x0000ffffa569a208
.... x13 0x0000000000000000
.... x14 0x0000000000000000
.... x15 0x0000000000000000
.... x16 0x0000aaaad3de9650
.... x17 0x0000ffffa57397f0
.... x18 0x0000000000000001
.... x19 0x0000ffffa57fd000
.... x20 0x0000ffffd1515817
.... x21 0x0000ffffd1515480
.... x22 0x0000aaaadabf6c80
.... x23 0x0000000000000000
.... x24 0x0000000000000001
.... x25 0x0000000000000000
.... x26 0x0000000000000000
.... x27 0x0000000000000000
.... x28 0x0000000000000000
.... x29 0x0000ffffd1510d90
.... lr 0x0000ffffa5739b90
.... sp 0x0000ffffd1510d80
.... pc 0x0000ffffa57392c8
... thread: perf-exec:43239
...... dso: [kernel.kallsyms]
Tester comments:
Athira reports:
"Looks good to me. Tested this patchset in powerpc by capturing regs in
powerpc and doing perf report to read the data from x86."
Reported-by: Alexandre Truong <alexandre.truong@arm.com>
Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: German Gomez <german.gomez@arm.com>
Tested-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-csky@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Link: https://lore.kernel.org/r/20211207180653.1147374-4-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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gcc version: 11.0.0 20210208 (experimental) (GCC)
Following build error on arm64:
.......
In function ‘printf’,
inlined from ‘regs_dump__printf’ at util/session.c:1141:3,
inlined from ‘regs__printf’ at util/session.c:1169:2:
/usr/include/aarch64-linux-gnu/bits/stdio2.h:107:10: \
error: ‘%-5s’ directive argument is null [-Werror=format-overflow=]
107 | return __printf_chk (__USE_FORTIFY_LEVEL - 1, __fmt, \
__va_arg_pack ());
......
In function ‘fprintf’,
inlined from ‘perf_sample__fprintf_regs.isra’ at \
builtin-script.c:622:14:
/usr/include/aarch64-linux-gnu/bits/stdio2.h:100:10: \
error: ‘%5s’ directive argument is null [-Werror=format-overflow=]
100 | return __fprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt,
101 | __va_arg_pack ());
cc1: all warnings being treated as errors
.......
This patch fixes Wformat-overflow warnings. Add helper function to
convert NULL to "unknown".
Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: iecedge@gmail.com
Cc: linux-csky@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Link: http://lore.kernel.org/lkml/20210218031245.2078492-1-Jianlin.Lv@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Being const + weak breaks with some compilers that constant-propagate
from the weak symbol. This behavior is outside of the specification, but
in LLVM is chosen to match GCC's behavior.
LLVM's implementation was set in this patch:
https://github.com/llvm/llvm-project/commit/f49573d1eedcf1e44893d5a062ac1b72c8419646
A const + weak symbol is set to be weak_odr:
https://llvm.org/docs/LangRef.html
ODR is one definition rule, and given there is one constant definition
constant-propagation is possible. It is possible to get this code to
miscompile with LLVM when applying link time optimization. As compilers
become more aggressive, this is likely to break in more instances.
Move the definition of sample_reg_masks to the conditional part of
perf_regs.h and guard usage with HAVE_PERF_REGS_SUPPORT. This avoids the
weak symbol.
Fix an issue when HAVE_PERF_REGS_SUPPORT isn't defined from patch v1.
In v3, add perf_regs.c for architectures that HAVE_PERF_REGS_SUPPORT but
don't declare sample_regs_masks.
Further notes:
Jiri asked:
"Is this just a precaution or you actualy saw some breakage?"
Ian answered:
"We saw a breakage with clang with thinlto enabled for linking. Our
compiler team had recently seen, and were surprised by, a similar issue
and were able to dig out the weak ODR issue."
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Guo Ren <guoren@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: linux-riscv@lists.infradead.org
Cc: Mao Han <han_mao@c-sky.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20191001003623.255186-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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This patch add basic arch initialization and instruction associate
support for the csky CPU architecture.
E.g.:
$ perf annotate --stdio2
Samples: 161 of event 'cpu-clock:pppH', 4000 Hz, Event count (approx.):
40250000, [percent: local period]
test_4() /usr/lib/perf-test/callchain_test
Percent
Disassembly of section .text:
00008420 <test_4>:
test_4():
subi sp, sp, 4
st.w r8, (sp, 0x0)
mov r8, sp
subi sp, sp, 8
subi r3, r8, 4
movi r2, 0
st.w r2, (r3, 0x0)
↓ br 2e
100.00 14: subi r3, r8, 4
ld.w r2, (r3, 0x0)
subi r3, r8, 8
st.w r2, (r3, 0x0)
subi r3, r8, 4
ld.w r3, (r3, 0x0)
addi r2, r3, 1
subi r3, r8, 4
st.w r2, (r3, 0x0)
2e: subi r3, r8, 4
ld.w r2, (r3, 0x0)
lrw r3, 0x98967f // 8598 <main+0x28>
cmplt r3, r2
↑ bf 14
mov r0, r0
mov r0, r0
mov sp, r8
ld.w r8, (sp, 0x0)
addi sp, sp, 4
← rts
Signed-off-by: Mao Han <han_mao@c-sky.com>
Acked-by: Guo Ren <guoren@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-csky@vger.kernel.org
Link: http://lkml.kernel.org/r/d874d7782d9acdad5d98f2f5c4a6fb26fbe41c5d.1561531557.git.han_mao@c-sky.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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