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H A Dsymbol-elf.ce59fea47 Fri Aug 11 00:15:46 CDT 2023 Athira Rajeev <atrajeev@linux.vnet.ibm.com> perf symbols: Fix DSO kernel load and symbol process to correctly map DSO to its long_name, type and adjust_symbols

Test "object code reading" fails sometimes for kernel address as below:

Reading object code for memory address: 0xc000000000004c3c
File is: [kernel.kallsyms]
On file address is: 0x14c3c
dso__data_read_offset failed
test child finished with -1
---- end ----
Object code reading: FAILED!

Here dso__data_read_offset() fails for symbol address
0xc000000000004c3c. This is because the DSO long_name here is
"[kernel.kallsyms]" and hence open_dso() fails to open this file. There
is an incorrect DSO to map handling here. The key points here are:

- The DSO long_name is set to "[kernel.kallsyms]". This file is
not present and hence returns error
- The DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
- The DSO adjust_symbols member is set to zero

In the end dso__data_read_offset() returns -1 and the address 0x14c3c
can not be resolved. Hence the test fails. But the address actually maps
to the kernel DSO

# objdump -z -d --start-address=0xc000000000004c3c --stop-address=0xc000000000004cbc /home/athira/linux/vmlinux

/home/athira/linux/vmlinux: file format elf64-powerpcle

Disassembly of section .head.text:

c000000000004c3c <exc_virt_0x4c00_system_call+0x3c>:
c000000000004c3c: a6 02 9b 7d mfsrr1 r12
c000000000004c40: 78 13 42 7c mr r2,r2
c000000000004c44: 18 00 4d e9 ld r10,24(r13)
c000000000004c48: 60 c6 4a 61 ori r10,r10,50784
c000000000004c4c: a6 03 49 7d mtctr r10

Fix dso__process_kernel_symbol() to set the binary_type and
adjust_symbols members. dso->adjust_symbols is used by
map__rip_2objdump() which converts the symbol start address to the
objdump address. Also set dso->long_name in dso__load_vmlinux().

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230811051546.70039-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
H A Dsymbol.ce59fea47 Fri Aug 11 00:15:46 CDT 2023 Athira Rajeev <atrajeev@linux.vnet.ibm.com> perf symbols: Fix DSO kernel load and symbol process to correctly map DSO to its long_name, type and adjust_symbols

Test "object code reading" fails sometimes for kernel address as below:

Reading object code for memory address: 0xc000000000004c3c
File is: [kernel.kallsyms]
On file address is: 0x14c3c
dso__data_read_offset failed
test child finished with -1
---- end ----
Object code reading: FAILED!

Here dso__data_read_offset() fails for symbol address
0xc000000000004c3c. This is because the DSO long_name here is
"[kernel.kallsyms]" and hence open_dso() fails to open this file. There
is an incorrect DSO to map handling here. The key points here are:

- The DSO long_name is set to "[kernel.kallsyms]". This file is
not present and hence returns error
- The DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND
- The DSO adjust_symbols member is set to zero

In the end dso__data_read_offset() returns -1 and the address 0x14c3c
can not be resolved. Hence the test fails. But the address actually maps
to the kernel DSO

# objdump -z -d --start-address=0xc000000000004c3c --stop-address=0xc000000000004cbc /home/athira/linux/vmlinux

/home/athira/linux/vmlinux: file format elf64-powerpcle

Disassembly of section .head.text:

c000000000004c3c <exc_virt_0x4c00_system_call+0x3c>:
c000000000004c3c: a6 02 9b 7d mfsrr1 r12
c000000000004c40: 78 13 42 7c mr r2,r2
c000000000004c44: 18 00 4d e9 ld r10,24(r13)
c000000000004c48: 60 c6 4a 61 ori r10,r10,50784
c000000000004c4c: a6 03 49 7d mtctr r10

Fix dso__process_kernel_symbol() to set the binary_type and
adjust_symbols members. dso->adjust_symbols is used by
map__rip_2objdump() which converts the symbol start address to the
objdump address. Also set dso->long_name in dso__load_vmlinux().

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230811051546.70039-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>