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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 <[email protected]>
Reviewed-by: Athira Jajeev <[email protected]>
Signed-off-by: German Gomez <[email protected]>
Tested-by: Athira Jajeev <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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