On Fri, Sep 27, 2019 at 6:53 PM Steve MacLean <[email protected]> wrote: > > Specification claims latest version of jitdump file format is 2. Current > jit dump reading code treats 1 as the latest version. > > Correct spec to match code. > > The original language made it unclear the value to be written in the magic > field. > > Revise language that the writer always writes the same value. Specify that > the reader uses the value to detect endian mismatches. > > Cc: Peter Zijlstra <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Arnaldo Carvalho de Melo <[email protected]> > Cc: Mark Rutland <[email protected]> > Cc: Alexander Shishkin <[email protected]> > Cc: Jiri Olsa <[email protected]> > Cc: Namhyung Kim <[email protected]> > Cc: Stephane Eranian <[email protected]> > Cc: [email protected] > Signed-off-by: Steve MacLean <[email protected]>
Corrections are valid. Acked-by: Stephane Eranian <[email protected]> > --- > tools/perf/Documentation/jitdump-specification.txt | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/Documentation/jitdump-specification.txt > b/tools/perf/Documentation/jitdump-specification.txt > index 4c62b07..52152d1 100644 > --- a/tools/perf/Documentation/jitdump-specification.txt > +++ b/tools/perf/Documentation/jitdump-specification.txt > @@ -36,8 +36,8 @@ III/ Jitdump file header format > Each jitdump file starts with a fixed size header containing the following > fields in order: > > > -* uint32_t magic : a magic number tagging the file type. The value is > 4-byte long and represents the string "JiTD" in ASCII form. It is 0x4A695444 > or 0x4454694a depending on the endianness. The field can be used to detect > the endianness of the file > -* uint32_t version : a 4-byte value representing the format version. It is > currently set to 2 > +* uint32_t magic : a magic number tagging the file type. The value is > 4-byte long and represents the string "JiTD" in ASCII form. It written is as > 0x4A695444. The reader will detect an endian mismatch when it reads > 0x4454694a. > +* uint32_t version : a 4-byte value representing the format version. It is > currently set to 1 > * uint32_t total_size: size in bytes of file header > * uint32_t elf_mach : ELF architecture encoding (ELF e_machine value as > specified in /usr/include/elf.h) > * uint32_t pad1 : padding. Reserved for future use > -- > 2.7.4 >
