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Athira Rajeev authored
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 <disgoel@linux.ibm.com> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Kajol Jain <kjain@linux.ibm.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: maddy@linux.ibm.com Cc: disgoel@linux.vnet.ibm.com Cc: linuxppc-dev@lists.ozlabs.org Link: https://lore.kernel.org/r/20230928075213.84392-1-atrajeev@linux.vnet.ibm.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>
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