On Mon, Oct 2, 2023 at 11:47 PM Athira Rajeev <[email protected]> wrote: > > > > > On 03-Oct-2023, at 9:58 AM, Namhyung Kim <[email protected]> wrote: > > > > Hello, > > > > On Thu, Sep 28, 2023 at 12:52 AM Athira Rajeev > > <[email protected]> wrote: > >> > >> Update "struct dso" to include new member "text_end". > >> This new field will represent the offset for end of text > >> section for a dso. For elf, this value is derived as: > >> sh_size (Size of section in byes) + sh_offset (Section file > >> offst) of the elf header for text. > >> > >> For bfd, this value is derived as: > >> 1. For PE file, > >> section->size + ( section->vma - dso->text_offset) > >> 2. Other cases: > >> section->filepos (file position) + section->size (size of > >> section) > >> > >> To resolve the address from a sample, perf looks at the > >> DSO maps. In case of address from a kernel module, there > >> were some address found to be not resolved. This was > >> observed while running perf test for "Object code reading". > >> Though the ip falls beteen the start address of the loaded > >> module (perf map->start ) and end address ( perf map->end), > >> it was unresolved. > >> > >> Example: > >> > >> Reading object code for memory address: 0xc008000007f0142c > >> File is: /lib/modules/6.5.0-rc3+/kernel/fs/xfs/xfs.ko > >> On file address is: 0x1114cc > >> Objdump command is: objdump -z -d --start-address=0x11142c > >> --stop-address=0x1114ac /lib/modules/6.5.0-rc3+/kernel/fs/xfs/xfs.ko > >> objdump read too few bytes: 128 > >> test child finished with -1 > >> > >> Here, module is loaded at: > >> # cat /proc/modules | grep xfs > >> xfs 2228224 3 - Live 0xc008000007d00000 > >> > >> From objdump for xfs module, text section is: > >> text 0010f7bc 0000000000000000 0000000000000000 000000a0 2**4 > >> > >> Here the offset for 0xc008000007f0142c ie 0x112074 falls out > >> .text section which is up to 0x10f7bc. > >> > >> In this case for module, the address 0xc008000007e11fd4 is pointing > >> to stub instructions. This address range represents the module stubs > >> which is allocated on module load and hence is not part of DSO offset. > >> > >> To identify such address, which falls out of text > >> section and within module end, added the new field "text_end" to > >> "struct dso". > >> > >> Reported-by: Disha Goel <[email protected]> > >> Signed-off-by: Athira Rajeev <[email protected]> > >> Reviewed-by: Adrian Hunter <[email protected]> > >> Reviewed-by: Kajol Jain <[email protected]> > > > > For the series, > > Acked-by: Namhyung Kim <[email protected]> > > > > Thanks, > > Namhyung > > Thanks for checking Namhyung,
Applied to perf-tools-next, thanks!
