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173 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Adrian Hunter
|
ce4c8e7966 |
perf symbols: Get symbols for .plt.got for x86-64
For x86_64, determine a symbol for .plt.got entries. That requires
computing the target offset and finding that in .rela.dyn, which in
turn means .rela.dyn needs to be sorted by offset.
Example:
In this example, the GNU C Library is using .plt.got for malloc and
free.
Before:
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ perf record -e intel_pt//u uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.027 MB perf.data ]
$ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp1.txt
After:
$ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt | head -12
15509,15510c15509,15510
< 27046.755390907: 7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428380 offset_0x28380@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
< 27046.755390907: 7f0b29428384 offset_0x28380@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
---
> 27046.755390907: 7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428380 malloc@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
> 27046.755390907: 7f0b29428384 malloc@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
15821,15822c15821,15822
< 27046.755394865: 7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428370 offset_0x28370@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
< 27046.755394865: 7f0b29428374 offset_0x28370@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
---
> 27046.755394865: 7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b29428370 free@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
> 27046.755394865: 7f0b29428374 free@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) => 7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
51a188ad8c |
perf symbols: Start adding support for .plt.got for x86
For x86, .plt.got is used, for example, when the address is taken of a
dynamically linked function. Start adding support by synthesizing a
symbol for each entry. A subsequent patch will attempt to get a better
name for the symbol.
Example:
Before:
$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltgot.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);
void callfn(void (*fn)(void))
{
fn();
}
int main()
{
fn4();
fn1();
callfn(fn3);
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -o tstpltgot tstpltgot.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -SW tstpltgot | grep 'Name\|plt\|dyn'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 6] .dynsym DYNSYM 00000000000003d8 0003d8 0000f0 18 A 7 1 8
[ 7] .dynstr STRTAB 00000000000004c8 0004c8 0000c6 00 A 0 0 1
[10] .rela.dyn RELA 00000000000005d8 0005d8 0000d8 18 A 6 0 8
[11] .rela.plt RELA 00000000000006b0 0006b0 000048 18 AI 6 24 8
[13] .plt PROGBITS 0000000000001020 001020 000040 10 AX 0 0 16
[14] .plt.got PROGBITS 0000000000001060 001060 000020 10 AX 0 0 16
[15] .plt.sec PROGBITS 0000000000001080 001080 000030 10 AX 0 0 16
[23] .dynamic DYNAMIC 0000000000003d90 002d90 000210 10 WA 7 0 8
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltgot , filter callfn @ ./tstpltgot' ./tstpltgot
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.011 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0
28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd
28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12
28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0
28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0
28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16
28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21
28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0
28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26
28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 [unknown] <- call to fn3 via .plt.got
28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b
28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
28393.810326915: tr strt 0 [unknown] => 562350baa1b2 main+0x0
28393.810326915: tr end call 562350baa1ba main+0x8 => 562350baa090 fn4@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1bf main+0xd
28393.810326917: tr end call 562350baa1bf main+0xd => 562350baa080 fn1@plt+0x0
28393.810326917: tr strt 0 [unknown] => 562350baa1c4 main+0x12
28393.810326917: call 562350baa1ce main+0x1c => 562350baa199 callfn+0x0
28393.810326917: tr end call 562350baa1ad callfn+0x14 => 7f607d36110f fn3+0x0
28393.810326922: tr strt 0 [unknown] => 562350baa1af callfn+0x16
28393.810326922: return 562350baa1b1 callfn+0x18 => 562350baa1d3 main+0x21
28393.810326922: tr end call 562350baa1d3 main+0x21 => 562350baa0a0 fn2@plt+0x0
28393.810326924: tr strt 0 [unknown] => 562350baa1d8 main+0x26
28393.810326924: tr end call 562350baa1d8 main+0x26 => 562350baa060 offset_0x1060@plt+0x0
28393.810326925: tr strt 0 [unknown] => 562350baa1dd main+0x2b
28393.810326925: tr end return 562350baa1e3 main+0x31 => 7f607d029d90 __libc_start_call_main+0x80
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
a1ab12856f |
perf symbols: Allow for static executables with .plt
A statically linked executable can have a .plt due to IFUNCs, in which
case .symtab is used not .dynsym. Check the section header link to see
if that is the case, and then use symtab instead.
Example:
Before:
$ cat tstifunc.c
#include <stdio.h>
void thing1(void)
{
printf("thing1\n");
}
void thing2(void)
{
printf("thing2\n");
}
typedef void (*thing_fn_t)(void);
thing_fn_t thing_ifunc(void)
{
int x;
if (x & 1)
return thing2;
return thing1;
}
void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
int main()
{
thing();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -static -Wall -Wextra -Wno-uninitialized -o tstifuncstatic tstifunc.c
$ readelf -SW tstifuncstatic | grep 'Name\|plt\|dyn'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 4] .rela.plt RELA 00000000004002e8 0002e8 000258 18 AI 29 20 8
[ 6] .plt PROGBITS 0000000000401020 001020 000190 00 AX 0 0 16
[20] .got.plt PROGBITS 00000000004c5000 0c4000 0000e0 08 WA 0 0 8
$ perf record -e intel_pt//u --filter 'filter main @ ./tstifuncstatic' ./tstifuncstatic
thing1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.008 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
15786.690189535: tr strt 0 [unknown] => 4017cd main+0x0
15786.690189535: tr end call 4017d5 main+0x8 => 401170 [unknown]
15786.690197660: tr strt 0 [unknown] => 4017da main+0xd
15786.690197660: tr end return 4017e0 main+0x13 => 401c1a __libc_start_call_main+0x6a
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
15786.690189535: tr strt 0 [unknown] => 4017cd main+0x0
15786.690189535: tr end call 4017d5 main+0x8 => 401170 thing_ifunc@plt+0x0
15786.690197660: tr strt 0 [unknown] => 4017da main+0xd
15786.690197660: tr end return 4017e0 main+0x13 => 401c1a __libc_start_call_main+0x6a
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
60fbb3e49a |
perf symbols: Allow for .plt without header
A static executable can have a .plt due to the presence of IFUNCs. In that case the .plt does not have a header. Check for whether there is a header by comparing the number of entries to the number of relocation entries. Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230131131625.6964-7-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
b7dbc0be6e |
perf symbols: Add support for IFUNC symbols for x86_64
For x86_64, the GNU linker is putting IFUNC information in the relocation
addend, so use it to try to find a symbol for plt entries that refer to
IFUNCs.
Example:
Before:
$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltifunc.c
#include <stdio.h>
void thing1(void)
{
printf("thing1\n");
}
void thing2(void)
{
printf("thing2\n");
}
typedef void (*thing_fn_t)(void);
thing_fn_t thing_ifunc(void)
{
int x;
if (x & 1)
return thing2;
return thing1;
}
void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);
int main()
{
fn4();
fn1();
thing();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -rW tstpltifunc | grep -A99 plt
Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000003f98 0000000300000007 R_X86_64_JUMP_SLOT 0000000000000000 puts@GLIBC_2.2.5 + 0
0000000000003fa8 0000000400000007 R_X86_64_JUMP_SLOT 0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
0000000000003fb0 0000000500000007 R_X86_64_JUMP_SLOT 0000000000000000 fn1 + 0
0000000000003fb8 0000000600000007 R_X86_64_JUMP_SLOT 0000000000000000 fn3 + 0
0000000000003fc0 0000000800000007 R_X86_64_JUMP_SLOT 0000000000000000 fn4 + 0
0000000000003fc8 0000000900000007 R_X86_64_JUMP_SLOT 0000000000000000 fn2 + 0
0000000000003fd0 0000000b00000007 R_X86_64_JUMP_SLOT 0000000000000000 getrandom@GLIBC_2.25 + 0
0000000000003fa0 0000000000000025 R_X86_64_IRELATIVE 125d
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
thing2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
21860.073683659: tr strt 0 [unknown] => 561e212c42be main+0x0
21860.073683659: tr end call 561e212c42c6 main+0x8 => 561e212c4110 fn4@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42cb main+0xd
21860.073683661: tr end call 561e212c42cb main+0xd => 561e212c40f0 fn1@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42d0 main+0x12
21860.073683661: tr end call 561e212c42d0 main+0x12 => 561e212c40d0 offset_0x10d0@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42d5 main+0x17
21860.073698451: tr end call 561e212c42d5 main+0x17 => 561e212c4120 fn2@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42da main+0x1c
21860.073698451: tr end call 561e212c42da main+0x1c => 561e212c4100 fn3@plt+0x0
21860.073698452: tr strt 0 [unknown] => 561e212c42df main+0x21
21860.073698452: tr end return 561e212c42e5 main+0x27 => 7fb51cc29d90 __libc_start_call_main+0x80
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
21860.073683659: tr strt 0 [unknown] => 561e212c42be main+0x0
21860.073683659: tr end call 561e212c42c6 main+0x8 => 561e212c4110 fn4@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42cb main+0xd
21860.073683661: tr end call 561e212c42cb main+0xd => 561e212c40f0 fn1@plt+0x0
21860.073683661: tr strt 0 [unknown] => 561e212c42d0 main+0x12
21860.073683661: tr end call 561e212c42d0 main+0x12 => 561e212c40d0 thing_ifunc@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42d5 main+0x17
21860.073698451: tr end call 561e212c42d5 main+0x17 => 561e212c4120 fn2@plt+0x0
21860.073698451: tr strt 0 [unknown] => 561e212c42da main+0x1c
21860.073698451: tr end call 561e212c42da main+0x1c => 561e212c4100 fn3@plt+0x0
21860.073698452: tr strt 0 [unknown] => 561e212c42df main+0x21
21860.073698452: tr end return 561e212c42e5 main+0x27 => 7fb51cc29d90 __libc_start_call_main+0x80
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
78250284b1 |
perf symbols: Sort plt relocations for x86
For x86, with the addition of IFUNCs, relocation information becomes
disordered with respect to plt. Correct that by sorting the relocations by
offset.
Example:
Before:
$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstpltifunc.c
#include <stdio.h>
void thing1(void)
{
printf("thing1\n");
}
void thing2(void)
{
printf("thing2\n");
}
typedef void (*thing_fn_t)(void);
thing_fn_t thing_ifunc(void)
{
int x;
if (x & 1)
return thing2;
return thing1;
}
void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);
int main()
{
fn4();
fn1();
thing();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
$ readelf -rW tstpltifunc | grep -A99 plt
Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000003f98 0000000300000007 R_X86_64_JUMP_SLOT 0000000000000000 puts@GLIBC_2.2.5 + 0
0000000000003fa8 0000000400000007 R_X86_64_JUMP_SLOT 0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
0000000000003fb0 0000000500000007 R_X86_64_JUMP_SLOT 0000000000000000 fn1 + 0
0000000000003fb8 0000000600000007 R_X86_64_JUMP_SLOT 0000000000000000 fn3 + 0
0000000000003fc0 0000000800000007 R_X86_64_JUMP_SLOT 0000000000000000 fn4 + 0
0000000000003fc8 0000000900000007 R_X86_64_JUMP_SLOT 0000000000000000 fn2 + 0
0000000000003fd0 0000000b00000007 R_X86_64_JUMP_SLOT 0000000000000000 getrandom@GLIBC_2.25 + 0
0000000000003fa0 0000000000000025 R_X86_64_IRELATIVE 125d
$ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
thing2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.029 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
20417.302513948: tr strt 0 [unknown] => 5629a74892be main+0x0
20417.302513948: tr end call 5629a74892c6 main+0x8 => 5629a7489110 fn2@plt+0x0
20417.302513949: tr strt 0 [unknown] => 5629a74892cb main+0xd
20417.302513949: tr end call 5629a74892cb main+0xd => 5629a74890f0 fn3@plt+0x0
20417.302513950: tr strt 0 [unknown] => 5629a74892d0 main+0x12
20417.302513950: tr end call 5629a74892d0 main+0x12 => 5629a74890d0 __stack_chk_fail@plt+0x0
20417.302528114: tr strt 0 [unknown] => 5629a74892d5 main+0x17
20417.302528114: tr end call 5629a74892d5 main+0x17 => 5629a7489120 getrandom@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892da main+0x1c
20417.302528115: tr end call 5629a74892da main+0x1c => 5629a7489100 fn4@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892df main+0x21
20417.302528115: tr end return 5629a74892e5 main+0x27 => 7ff14da29d90 __libc_start_call_main+0x80
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
20417.302513948: tr strt 0 [unknown] => 5629a74892be main+0x0
20417.302513948: tr end call 5629a74892c6 main+0x8 => 5629a7489110 fn4@plt+0x0
20417.302513949: tr strt 0 [unknown] => 5629a74892cb main+0xd
20417.302513949: tr end call 5629a74892cb main+0xd => 5629a74890f0 fn1@plt+0x0
20417.302513950: tr strt 0 [unknown] => 5629a74892d0 main+0x12
20417.302513950: tr end call 5629a74892d0 main+0x12 => 5629a74890d0 offset_0x10d0@plt+0x0
20417.302528114: tr strt 0 [unknown] => 5629a74892d5 main+0x17
20417.302528114: tr end call 5629a74892d5 main+0x17 => 5629a7489120 fn2@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892da main+0x1c
20417.302528115: tr end call 5629a74892da main+0x1c => 5629a7489100 fn3@plt+0x0
20417.302528115: tr strt 0 [unknown] => 5629a74892df main+0x21
20417.302528115: tr end return 5629a74892e5 main+0x27 => 7ff14da29d90 __libc_start_call_main+0x80
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
b2529f829a |
perf symbols: Add support for x86 .plt.sec
The section .plt.sec was originally added for MPX and was first called
.plt.bnd. While MPX has been deprecated, .plt.sec is now also used for
IBT. On x86_64, IBT may be enabled by default, but can be switched off
using gcc option -fcf-protection=none, or switched on by -z ibt or -z
ibtplt. On 32-bit, option -z ibt or -z ibtplt will enable IBT.
With .plt.sec, calls are made into .plt.sec instead of .plt, so it makes
more sense to put the symbols there instead of .plt. A notable
difference is that .plt.sec does not have a header entry.
For x86, when synthesizing symbols for plt, use offset and entry size of
.plt.sec instead of .plt when there is a .plt.sec section.
Example on Ubuntu 22.04 gcc 11.3:
Before:
$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstplt.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);
int main()
{
fn4();
fn1();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
$ gcc -Wall -Wextra -z ibt -o tstplt tstplt.c -L . -ltstpltlib -Wl,-rpath=$(pwd)
$ readelf -SW tstplt | grep 'plt\|Name'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[11] .rela.plt RELA 0000000000000698 000698 000060 18 AI 6 24 8
[13] .plt PROGBITS 0000000000001020 001020 000050 10 AX 0 0 16
[14] .plt.got PROGBITS 0000000000001070 001070 000010 10 AX 0 0 16
[15] .plt.sec PROGBITS 0000000000001080 001080 000040 10 AX 0 0 16
$ perf record -e intel_pt//u --filter 'filter main @ ./tstplt' ./tstplt
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.015 MB perf.data ]
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
38970.522546686: tr strt 0 [unknown] => 55fc222a81a9 main+0x0
38970.522546686: tr end call 55fc222a81b1 main+0x8 => 55fc222a80a0 [unknown]
38970.522546687: tr strt 0 [unknown] => 55fc222a81b6 main+0xd
38970.522546687: tr end call 55fc222a81b6 main+0xd => 55fc222a8080 [unknown]
38970.522546688: tr strt 0 [unknown] => 55fc222a81bb main+0x12
38970.522546688: tr end call 55fc222a81bb main+0x12 => 55fc222a80b0 [unknown]
38970.522546688: tr strt 0 [unknown] => 55fc222a81c0 main+0x17
38970.522546688: tr end call 55fc222a81c0 main+0x17 => 55fc222a8090 [unknown]
38970.522546689: tr strt 0 [unknown] => 55fc222a81c5 main+0x1c
38970.522546894: tr end return 55fc222a81cb main+0x22 => 7f3a4dc29d90 __libc_start_call_main+0x80
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
38970.522546686: tr strt 0 [unknown] => 55fc222a81a9 main+0x0
38970.522546686: tr end call 55fc222a81b1 main+0x8 => 55fc222a80a0 fn4@plt+0x0
38970.522546687: tr strt 0 [unknown] => 55fc222a81b6 main+0xd
38970.522546687: tr end call 55fc222a81b6 main+0xd => 55fc222a8080 fn1@plt+0x0
38970.522546688: tr strt 0 [unknown] => 55fc222a81bb main+0x12
38970.522546688: tr end call 55fc222a81bb main+0x12 => 55fc222a80b0 fn2@plt+0x0
38970.522546688: tr strt 0 [unknown] => 55fc222a81c0 main+0x17
38970.522546688: tr end call 55fc222a81c0 main+0x17 => 55fc222a8090 fn3@plt+0x0
38970.522546689: tr strt 0 [unknown] => 55fc222a81c5 main+0x1c
38970.522546894: tr end return 55fc222a81cb main+0x22 => 7f3a4dc29d90 __libc_start_call_main+0x80
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
66fe2d53a0 |
perf symbols: Correct plt entry sizes for x86
In 32-bit executables the .plt entry size can be set to 4 when it is really
16. In fact the only sizes used for x86 (32 or 64 bit) are 8 or 16, so
check for those and, if not, use the alignment to choose which it is.
Example on Ubuntu 22.04 gcc 11.3:
Before:
$ cat tstpltlib.c
void fn1(void) {}
void fn2(void) {}
void fn3(void) {}
void fn4(void) {}
$ cat tstplt.c
void fn1(void);
void fn2(void);
void fn3(void);
void fn4(void);
int main()
{
fn4();
fn1();
fn2();
fn3();
return 0;
}
$ gcc --version
gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gcc -m32 -Wall -Wextra -shared -o libtstpltlib32.so tstpltlib.c
$ gcc -m32 -Wall -Wextra -o tstplt32 tstplt.c -L . -ltstpltlib32 -Wl,-rpath=$(pwd)
$ perf record -e intel_pt//u --filter 'filter main @ ./tstplt32' ./tstplt32
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.011 MB perf.data ]
$ readelf -SW tstplt32 | grep 'plt\|Name'
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[10] .rel.plt REL 0000041c 00041c 000028 08 AI 5 22 4
[12] .plt PROGBITS 00001030 001030 000060 04 AX 0 0 16 <- ES is 0x04, should be 0x10
[13] .plt.got PROGBITS 00001090 001090 000008 08 AX 0 0 8
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
17894.383903029: tr strt 0 [unknown] => 565b81cd main+0x0
17894.383903029: tr end call 565b81d4 main+0x7 => 565b80d0 __x86.get_pc_thunk.bx+0x0
17894.383903031: tr strt 0 [unknown] => 565b81d9 main+0xc
17894.383903031: tr end call 565b81df main+0x12 => 565b8070 [unknown]
17894.383903032: tr strt 0 [unknown] => 565b81e4 main+0x17
17894.383903032: tr end call 565b81e4 main+0x17 => 565b8050 [unknown]
17894.383903033: tr strt 0 [unknown] => 565b81e9 main+0x1c
17894.383903033: tr end call 565b81e9 main+0x1c => 565b8080 [unknown]
17894.383903033: tr strt 0 [unknown] => 565b81ee main+0x21
17894.383903033: tr end call 565b81ee main+0x21 => 565b8060 [unknown]
17894.383903237: tr strt 0 [unknown] => 565b81f3 main+0x26
17894.383903237: tr end return 565b81fc main+0x2f => f7c21519 [unknown]
After:
$ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
17894.383903029: tr strt 0 [unknown] => 565b81cd main+0x0
17894.383903029: tr end call 565b81d4 main+0x7 => 565b80d0 __x86.get_pc_thunk.bx+0x0
17894.383903031: tr strt 0 [unknown] => 565b81d9 main+0xc
17894.383903031: tr end call 565b81df main+0x12 => 565b8070 fn4@plt+0x0
17894.383903032: tr strt 0 [unknown] => 565b81e4 main+0x17
17894.383903032: tr end call 565b81e4 main+0x17 => 565b8050 fn1@plt+0x0
17894.383903033: tr strt 0 [unknown] => 565b81e9 main+0x1c
17894.383903033: tr end call 565b81e9 main+0x1c => 565b8080 fn2@plt+0x0
17894.383903033: tr strt 0 [unknown] => 565b81ee main+0x21
17894.383903033: tr end call 565b81ee main+0x21 => 565b8060 fn3@plt+0x0
17894.383903237: tr strt 0 [unknown] => 565b81f3 main+0x26
17894.383903237: tr end return 565b81fc main+0x2f => f7c21519 [unknown]
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
df8aeaefea |
perf symbols: Check SHT_RELA and SHT_REL type earlier
Make the code more readable by checking for SHT_RELA and SHT_REL type earlier. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-11-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
375a448184 |
perf symbols: Combine handling for SHT_RELA and SHT_REL
SHT_REL and SHT_RELA are handled the same way. Simplify by combining the handling. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-10-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
45204677d4 |
perf symbols: Allow for .plt entries with no symbol
Create a sensible name for .plt entries with no symbol.
Example:
Before:
$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp1.txt
After:
$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4c4
< test child forked, pid 53043
---
> test child forked, pid 54372
23,62c23,62
< 280f0-28100 g @plt
< 28100-28110 g @plt
< 28110-28120 g @plt
< 28120-28130 g @plt
< 28130-28140 g @plt
< 28140-28150 g @plt
< 28150-28160 g @plt
< 28160-28170 g @plt
< 28170-28180 g @plt
< 28180-28190 g @plt
< 28190-281a0 g @plt
< 281a0-281b0 g @plt
< 281b0-281c0 g @plt
< 281c0-281d0 g @plt
< 281d0-281e0 g @plt
< 281e0-281f0 g @plt
< 281f0-28200 g @plt
< 28200-28210 g @plt
< 28210-28220 g @plt
< 28220-28230 g @plt
< 28230-28240 g @plt
< 28240-28250 g @plt
< 28250-28260 g @plt
< 28260-28270 g @plt
< 28270-28280 g @plt
< 28280-28290 g @plt
< 28290-282a0 g @plt
< 282a0-282b0 g @plt
< 282b0-282c0 g @plt
< 282c0-282d0 g @plt
< 282d0-282e0 g @plt
< 282e0-282f0 g @plt
< 282f0-28300 g @plt
< 28300-28310 g @plt
< 28310-28320 g @plt
< 28320-28330 g @plt
< 28330-28340 g @plt
< 28340-28350 g @plt
< 28350-28360 g @plt
< 28360-28370 g @plt
---
> 280f0-28100 g offset_0x280f0@plt
> 28100-28110 g offset_0x28100@plt
> 28110-28120 g offset_0x28110@plt
> 28120-28130 g offset_0x28120@plt
> 28130-28140 g offset_0x28130@plt
> 28140-28150 g offset_0x28140@plt
> 28150-28160 g offset_0x28150@plt
> 28160-28170 g offset_0x28160@plt
> 28170-28180 g offset_0x28170@plt
> 28180-28190 g offset_0x28180@plt
> 28190-281a0 g offset_0x28190@plt
> 281a0-281b0 g offset_0x281a0@plt
> 281b0-281c0 g offset_0x281b0@plt
> 281c0-281d0 g offset_0x281c0@plt
> 281d0-281e0 g offset_0x281d0@plt
> 281e0-281f0 g offset_0x281e0@plt
> 281f0-28200 g offset_0x281f0@plt
> 28200-28210 g offset_0x28200@plt
> 28210-28220 g offset_0x28210@plt
> 28220-28230 g offset_0x28220@plt
> 28230-28240 g offset_0x28230@plt
> 28240-28250 g offset_0x28240@plt
> 28250-28260 g offset_0x28250@plt
> 28260-28270 g offset_0x28260@plt
> 28270-28280 g offset_0x28270@plt
> 28280-28290 g offset_0x28280@plt
> 28290-282a0 g offset_0x28290@plt
> 282a0-282b0 g offset_0x282a0@plt
> 282b0-282c0 g offset_0x282b0@plt
> 282c0-282d0 g offset_0x282c0@plt
> 282d0-282e0 g offset_0x282d0@plt
> 282e0-282f0 g offset_0x282e0@plt
> 282f0-28300 g offset_0x282f0@plt
> 28300-28310 g offset_0x28300@plt
> 28310-28320 g offset_0x28310@plt
> 28320-28330 g offset_0x28320@plt
> 28330-28340 g offset_0x28330@plt
> 28340-28350 g offset_0x28340@plt
> 28350-28360 g offset_0x28350@plt
> 28360-28370 g offset_0x28360@plt
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
698a0d1a1a |
perf symbols: Add symbol for .plt header
perf expands the _init symbol over .plt because there are no PLT symbols
at that point, but then dso__synthesize_plt_symbols() creates them.
Fix by truncating the previous symbol and inserting a symbol for .plt
header.
Example:
Before:
$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 191028
Problems creating module maps, continuing anyway...
Testing /usr/bin/uname
Overlapping symbols:
2000-25f0 g _init
2040-2050 g free@plt
test child finished with -1
---- end ----
Symbols: FAILED!
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp1.txt
After:
$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 194291
Testing /usr/bin/uname
test child finished with 0
---- end ----
Symbols: Ok
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4,5c4
< test child forked, pid 191031
< Problems creating module maps, continuing anyway...
---
> test child forked, pid 194296
9c8,9
< 2000-25f0 g _init
---
> 2000-2030 g _init
> 2030-2040 g .plt
100,103c100
< Overlapping symbols:
< 2000-25f0 g _init
< 2040-2050 g free@plt
< test child finished with -1
---
> test child finished with 0
105c102
< Symbols: FAILED!
---
> Symbols: Ok
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
|
Adrian Hunter
|
5fec9b171c |
perf symbols: Do not check ss->dynsym twice
ss->dynsym is checked to be not NULL twice. Remove the first check because, in fact, there can be a plt with no dynsym, which is something that will be dealt with later. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-7-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
477d5e35b4 |
perf symbols: Slightly simplify 'err' usage in dso__synthesize_plt_symbols()
Return zero directly instead of needless 'goto out_elf_end' that does the same thing. That allows 'err' to be initialized to -1 instead of having to change its value later. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-6-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
b08b20c309 |
perf symbols: Check plt_entry_size is not zero
The code expects non-zero plt_entry_size. Check it and add a debug message to print if it is zero. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-4-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
c2d066c090 |
perf symbols: Factor out get_plt_sizes()
Factor out get_plt_sizes() to make the code more readable and further changes to dso__synthesize_plt_symbols() easier to follow. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20230120123456.12449-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Namhyung Kim
|
06ea72a42d |
perf symbol: Add filename__has_section()
The filename__has_section() is to check if the given section name is in the binary. It'd be used for checking debug info for srcline. Committer notes: Added missing __maybe_unused to the unused filename__has_section() arguments in tools/perf/util/symbol-minimal.c. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20221215192817.2734573-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Ajay Kaher
|
6f520ce179 |
perf symbol: correction while adjusting symbol
perf doesn't provide proper symbol information for specially crafted
.debug files.
Sometimes .debug file may not have similar program header as runtime
ELF file. For example if we generate .debug file using objcopy
--only-keep-debug resulting file will not contain .text, .data and
other runtime sections. That means corresponding program headers will
have zero FileSiz and modified Offset.
Example: program header of text section of libxxx.so:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x00000000003d3000 0x00000000003d3000 0x00000000003d3000
0x000000000055ae80 0x000000000055ae80 R E 0x1000
Same program header after executing:
objcopy --only-keep-debug libxxx.so libxxx.so.debug
LOAD 0x0000000000001000 0x00000000003d3000 0x00000000003d3000
0x0000000000000000 0x000000000055ae80 R E 0x1000
Offset and FileSiz have been changed.
Following formula will not provide correct value, if program header
taken from .debug file (syms_ss):
sym.st_value -= phdr.p_vaddr - phdr.p_offset;
Correct program header information is located inside runtime ELF
file (runtime_ss).
Fixes:
|
||
|
Adrian Hunter
|
5b427df27b |
perf kcore_copy: Do not check /proc/modules is unchanged
/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.
However /proc/modules also might change due to reference counts changing
even though that does not make any difference.
Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.
Remove the comparison checking that /proc/modules is unchanged.
Fixes:
|
||
Ian Rogers
|
6d518ac7be |
perf symbol: Fail to read phdr workaround
The perf jvmti agent doesn't create program headers, in this case fallback on section headers as happened previously. Committer notes: To test this, from a public post by Ian: 1) download a Java workload dacapo-9.12-MR1-bach.jar from https://sourceforge.net/projects/dacapobench/ 2) build perf such as "make -C tools/perf O=/tmp/perf NO_LIBBFD=1" it should detect Java and create /tmp/perf/libperf-jvmti.so 3) run perf with the jvmti agent: perf record -k 1 java -agentpath:/tmp/perf/libperf-jvmti.so -jar dacapo-9.12-MR1-bach.jar -n 10 fop 4) run perf inject: perf inject -i perf.data -o perf-injected.data -j 5) run perf report perf report -i perf-injected.data | grep org.apache.fop With this patch reverted I see lots of symbols like: 0.00% java jitted-388040-4656.so [.] org.apache.fop.fo.FObj.bind(org.apache.fop.fo.PropertyList) With the patch ( |
||
Leo Yan
|
882528d2e7 |
perf symbol: Skip symbols if SHF_ALLOC flag is not set
Some symbols are observed with the 'st_value' field zeroed. E.g. libc.so.6 in Ubuntu contains a symbol '__evoke_link_warning_getwd' which resides in the '.gnu.warning.getwd' section. Unlike normal sections, such kind of sections are used for linker warning when a file calls deprecated functions, but they are not part of memory images, the symbols in these sections should be dropped. This patch checks the section attribute SHF_ALLOC bit, if the bit is not set, it skips symbols to avoid spurious ones. Suggested-by: Fangrui Song <maskray@google.com> Signed-off-by: Leo Yan <leo.yan@linaro.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Chang Rui <changruinj@gmail.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20220724060013.171050-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Leo Yan
|
2d86612aac |
perf symbol: Correct address for bss symbols
When using 'perf mem' and 'perf c2c', an issue is observed that tool
reports the wrong offset for global data symbols. This is a common
issue on both x86 and Arm64 platforms.
Let's see an example, for a test program, below is the disassembly for
its .bss section which is dumped with objdump:
...
Disassembly of section .bss:
0000000000004040 <completed.0>:
...
0000000000004080 <buf1>:
...
00000000000040c0 <buf2>:
...
0000000000004100 <thread>:
...
First we used 'perf mem record' to run the test program and then used
'perf --debug verbose=4 mem report' to observe what's the symbol info
for 'buf1' and 'buf2' structures.
# ./perf mem record -e ldlat-loads,ldlat-stores -- false_sharing.exe 8
# ./perf --debug verbose=4 mem report
...
dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 sh_addr: 0x4040 sh_offset: 0x3028
symbol__new: buf2 0x30a8-0x30e8
...
dso__load_sym_internal: adjusting symbol: st_value: 0x4080 sh_addr: 0x4040 sh_offset: 0x3028
symbol__new: buf1 0x3068-0x30a8
...
The perf tool relies on libelf to parse symbols, in executable and
shared object files, 'st_value' holds a virtual address; 'sh_addr' is
the address at which section's first byte should reside in memory, and
'sh_offset' is the byte offset from the beginning of the file to the
first byte in the section. The perf tool uses below formula to convert
a symbol's memory address to a file address:
file_address = st_value - sh_addr + sh_offset
^
` Memory address
We can see the final adjusted address ranges for buf1 and buf2 are
[0x30a8-0x30e8) and [0x3068-0x30a8) respectively, apparently this is
incorrect, in the code, the structure for 'buf1' and 'buf2' specifies
compiler attribute with 64-byte alignment.
The problem happens for 'sh_offset', libelf returns it as 0x3028 which
is not 64-byte aligned, combining with disassembly, it's likely libelf
doesn't respect the alignment for .bss section, therefore, it doesn't
return the aligned value for 'sh_offset'.
Suggested by Fangrui Song, ELF file contains program header which
contains PT_LOAD segments, the fields p_vaddr and p_offset in PT_LOAD
segments contain the execution info. A better choice for converting
memory address to file address is using the formula:
file_address = st_value - p_vaddr + p_offset
This patch introduces elf_read_program_header() which returns the
program header based on the passed 'st_value', then it uses the formula
above to calculate the symbol file address; and the debugging log is
updated respectively.
After applying the change:
# ./perf --debug verbose=4 mem report
...
dso__load_sym_internal: adjusting symbol: st_value: 0x40c0 p_vaddr: 0x3d28 p_offset: 0x2d28
symbol__new: buf2 0x30c0-0x3100
...
dso__load_sym_internal: adjusting symbol: st_value: 0x4080 p_vaddr: 0x3d28 p_offset: 0x2d28
symbol__new: buf1 0x3080-0x30c0
...
Fixes:
|
||
|
Namhyung Kim
|
838425f2de |
perf symbol: Pass is_kallsyms to symbols__fixup_end()
The symbol fixup is necessary for symbols in kallsyms since they don't
have size info. So we use the next symbol's address to calculate the
size. Now it's also used for user binaries because sometimes they miss
size for hand-written asm functions.
There's a arch-specific function to handle kallsyms differently but
currently it cannot distinguish kallsyms from others. Pass this
information explicitly to handle it properly. Note that those arch
functions will be moved to the generic function so I didn't added it to
the arch-functions.
Fixes:
|
||
Riccardo Mancini
|
83952286f2 |
perf top: Fix overflow in elf_sec__is_text()
ASan reports a heap-buffer-overflow in elf_sec__is_text when using perf-top.
The bug is caused by the fact that secstrs is built from runtime_ss, while
shdr is built from syms_ss if shdr.sh_type != SHT_NOBITS. Therefore, they
point to two different ELF files.
This patch renames secstrs to secstrs_run and adds secstrs_sym, so that
the correct secstrs is chosen depending on shdr.sh_type.
$ ASAN_OPTIONS=abort_on_error=1:disable_coredump=0:unmap_shadow_on_exit=1 ./perf top
=================================================================
==363148==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61300009add6 at pc 0x00000049875c bp 0x7f4f56446440 sp 0x7f4f56445bf0
READ of size 1 at 0x61300009add6 thread T6
#0 0x49875b in StrstrCheck(void*, char*, char const*, char const*) (/home/user/linux/tools/perf/perf+0x49875b)
#1 0x4d13a2 in strstr (/home/user/linux/tools/perf/perf+0x4d13a2)
#2 0xacae36 in elf_sec__is_text /home/user/linux/tools/perf/util/symbol-elf.c:176:9
#3 0xac3ec9 in elf_sec__filter /home/user/linux/tools/perf/util/symbol-elf.c:187:9
#4 0xac2c3d in dso__load_sym /home/user/linux/tools/perf/util/symbol-elf.c:1254:20
#5 0x883981 in dso__load /home/user/linux/tools/perf/util/symbol.c:1897:9
#6 0x8e6248 in map__load /home/user/linux/tools/perf/util/map.c:332:7
#7 0x8e66e5 in map__find_symbol /home/user/linux/tools/perf/util/map.c:366:6
#8 0x7f8278 in machine__resolve /home/user/linux/tools/perf/util/event.c:707:13
#9 0x5f3d1a in perf_event__process_sample /home/user/linux/tools/perf/builtin-top.c:773:6
#10 0x5f30e4 in deliver_event /home/user/linux/tools/perf/builtin-top.c:1197:3
#11 0x908a72 in do_flush /home/user/linux/tools/perf/util/ordered-events.c:244:9
#12 0x905fae in __ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:323:8
#13 0x9058db in ordered_events__flush /home/user/linux/tools/perf/util/ordered-events.c:341:9
#14 0x5f19b1 in process_thread /home/user/linux/tools/perf/builtin-top.c:1109:7
#15 0x7f4f6a21a298 in start_thread /usr/src/debug/glibc-2.33-16.fc34.x86_64/nptl/pthread_create.c:481:8
#16 0x7f4f697d0352 in clone ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
0x61300009add6 is located 10 bytes to the right of 332-byte region [0x61300009ac80,0x61300009adcc)
allocated by thread T6 here:
#0 0x4f3f7f in malloc (/home/user/linux/tools/perf/perf+0x4f3f7f)
#1 0x7f4f6a0a88d9 (/lib64/libelf.so.1+0xa8d9)
Thread T6 created by T0 here:
#0 0x464856 in pthread_create (/home/user/linux/tools/perf/perf+0x464856)
#1 0x5f06e0 in __cmd_top /home/user/linux/tools/perf/builtin-top.c:1309:6
#2 0x5ef19f in cmd_top /home/user/linux/tools/perf/builtin-top.c:1762:11
#3 0x7b28c0 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
#4 0x7b119f in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
#5 0x7b2423 in run_argv /home/user/linux/tools/perf/perf.c:409:2
#6 0x7b0c19 in main /home/user/linux/tools/perf/perf.c:539:3
#7 0x7f4f696f7b74 in __libc_start_main /usr/src/debug/glibc-2.33-16.fc34.x86_64/csu/../csu/libc-start.c:332:16
SUMMARY: AddressSanitizer: heap-buffer-overflow (/home/user/linux/tools/perf/perf+0x49875b) in StrstrCheck(void*, char*, char const*, char const*)
Shadow bytes around the buggy address:
0x0c268000b560: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b570: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b580: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b590: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c268000b5b0: 00 00 00 00 00 00 00 00 00 04[fa]fa fa fa fa fa
0x0c268000b5c0: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
0x0c268000b5d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c268000b5f0: 07 fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c268000b600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==363148==ABORTING
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Fabian Hemmer <copy@copy.sh>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Remi Bernon <rbernon@codeweavers.com>
Link: http://lore.kernel.org/lkml/20210621222108.196219-1-rickyman7@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
Masami Hiramatsu
|
87704345cc |
perf symbol-elf: Decode dynsym even if symtab exists
In Fedora34, libc-2.33.so has both .dynsym and .symtab sections and most of (not all) symbols moved to .dynsym. In this case, perf only decode the symbols in .symtab, and perf probe can not list up the functions in the library. To fix this issue, decode both .symtab and .dynsym sections. Without this fix, ----- $ ./perf probe -x /usr/lib64/libc-2.33.so -F @plt @plt calloc@plt free@plt malloc@plt memalign@plt realloc@plt ----- With this fix. ----- $ ./perf probe -x /usr/lib64/libc-2.33.so -F @plt @plt a64l abort abs accept accept4 access acct addmntent ----- Reported-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Thomas Richter <tmricht@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Stefan Liebler <stli@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Link: http://lore.kernel.org/lkml/162532652681.393143.10163733179955267999.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Riccardo Mancini
|
69c9ffed6c |
perf symbol-elf: Fix memory leak by freeing sdt_note.args
Reported by ASan. Signed-off-by: Riccardo Mancini <rickyman7@gmail.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Fabian Hemmer <copy@copy.sh> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Remi Bernon <rbernon@codeweavers.com> Cc: Jiri Slaby <jirislaby@kernel.org> Link: http://lore.kernel.org/lkml/20210602220833.285226-1-rickyman7@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Ingo Molnar
|
4d39c89f0b |
perf tools: Fix various typos in comments
Fix ~124 single-word typos and a few spelling errors in the perf tooling code, accumulated over the years. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Fabian Hemmer
|
cef7af25c9 |
perf tools: Add OCaml demangling
Detect symbols generated by the OCaml compiler based on their prefix. Demangle OCaml symbols, returning a newly allocated string (like the existing Java demangling functionality). Move a helper function (hex) from tests/code-reading.c to util/string.c To test: echo 'Printf.printf "%d\n" (Random.int 42)' > test.ml perf record ocamlopt.opt test.ml perf report -d ocamlopt.opt Signed-off-by: Fabian Hemmer <copy@copy.sh> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> LPU-Reference: 20210203211537.b25ytjb6dq5jfbwx@nyu Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Jiri Slaby
|
6833e0b81a |
perf symbols: Resolve symbols against debug file first
With LTO, there are symbols like these:
/usr/lib/debug/usr/lib64/libantlr4-runtime.so.4.8-4.8-1.4.x86_64.debug
10305: 0000000000955fa4 0 NOTYPE LOCAL DEFAULT 29 Predicate.cpp.2bc410e7
This comes from a runtime/debug split done by the standard way:
objcopy --only-keep-debug $runtime $debug
objcopy --add-gnu-debuglink=$debugfn -R .comment -R .GCC.command.line --strip-all $runtime
perf currently cannot resolve such symbols (relicts of LTO), as section
29 exists only in the debug file (29 is .debug_info). And perf resolves
symbols only against runtime file. This results in all symbols from such
a library being unresolved:
0.38% main2 libantlr4-runtime.so.4.8 [.] 0x00000000000671e0
So try resolving against the debug file first. And only if it fails (the
section has NOBITS set), try runtime file. We can do this, as "objcopy
--only-keep-debug" per documentation preserves all sections, but clears
data of some of them (the runtime ones) and marks them as NOBITS.
The correct result is now:
0.38% main2 libantlr4-runtime.so.4.8 [.] antlr4::IntStream::~IntStream
Note that these LTO symbols are properly skipped anyway as they belong
neither to *text* nor to *data* (is_label && !elf_sec__filter(&shdr,
secstrs) is true).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210217122125.26416-1-jslaby@suse.cz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||
Jiri Olsa
|
47dce51acc |
perf tools: Add support to read build id from compressed elf
Adding support to decompress file before reading build id. Adding filename__read_build_id and change its current versions to read_build_id. Shutting down stderr output of perf list in the shell test: 82: Check open filename arg using perf trace + vfs_getname : Ok because with decompression code in the place we the filename__read_build_id function is more verbose in case of error and the test did not account for that. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Budankov <abudankov@huawei.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20201214105457.543111-7-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Jiri Olsa
|
39be8d0115 |
perf tools: Pass build_id object to dso__build_id_equal()
Passing build_id object to dso__build_id_equal(), so we can properly check build id with different size than sha1. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20201013192441.1299447-7-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Jiri Olsa
|
3ff1b8c8cc |
perf tools: Pass build id object to sysfs__read_build_id()
Passing build id object to sysfs__read_build_id function, so it can populate the size of the build_id object. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20201013192441.1299447-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Jiri Olsa
|
f766819cd5 |
perf tools: Pass build_id object to filename__read_build_id()
Pass a build_id object to filename__read_build_id function, so it can populate the size of the build_id object. Changing filename__read_build_id() code for both ELF/non-ELF code. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20201013192441.1299447-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
Remi Bernon
|
ba0509dcb7 |
perf dso: Use libbfd to read build_id and .gnu_debuglink section
Wine generates PE binaries for most of its modules and perf is unable to parse these files to get build_id or .gnu_debuglink section. Using libbfd when available, instead of libelf, makes it possible to resolve debug file location regardless of the dso binary format. Committer notes: Made the filename__read_build_id() variant that uses abfd->build_id depend on the feature test that defines HAVE_LIBBFD_BUILDID_SUPPORT, to get this to continue building with older libbfd/binutils. Signed-off-by: Remi Bernon <rbernon@codeweavers.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jacek Caban <jacek@codeweavers.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/20200821165238.1340315-1-rbernon@codeweavers.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Jiri Olsa
|
b2fe96a350 |
perf tools: Fix module symbol processing
The 'dso->kernel' condition is true also for kernel modules now,
and there are several places that were omited by the initial change:
- we need to identify modules separately in dso__process_kernel_symbol
- we need to set 'dso->kernel' for module from buildid table
- there's no need to use 'dso->kernel || kmodule' in one condition
Committer testing:
Before:
# perf test -v object
<SNIP>
Objdump command is: objdump -z -d --start-address=0xffffffff813e682f --stop-address=0xffffffff813e68af /usr/lib/debug/lib/modules/5.7.14-200.fc32.x86_64/vmlinux
Bytes read match those read by objdump
Reading object code for memory address: 0xffffffffc02dc257
File is: /lib/modules/5.7.14-200.fc32.x86_64/kernel/arch/x86/crypto/crc32c-intel.ko.xz
On file address is: 0xffffffffc02dc2e7
dso__data_read_offset failed
test child finished with -1
---- end ----
Object code reading: FAILED!
#
After:
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
# perf test object
26: Object code reading : Ok
#
Fixes:
|
||
|
Jiri Olsa
|
1c695c88a1 |
perf tools: Rename 'enum dso_kernel_type' to 'enum dso_space_type'
Rename enum dso_kernel_type to enum dso_space_type, which seems like better fit. Committer notes: This is used with 'struct dso'->kernel, which once was a boolean, so DSO_SPACE__USER is zero, !zero means some sort of kernel space, be it the host kernel space or a guest kernel space. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Adrian Hunter
|
61f82e3fb6 |
perf kcore_copy: Fix module map when there are no modules loaded
In the absence of any modules, no "modules" map is created, but there are other executable pages to map, due to eBPF JIT, kprobe or ftrace. Map them by recognizing that the first "module" symbol is not necessarily from a module, and adjust the map accordingly. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: x86@kernel.org Link: http://lore.kernel.org/lkml/20200512121922.8997-10-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
||
|
Leo Yan
|
7eec00a747 |
perf symbols: Consolidate symbol fixup issue
After copying Arm64's perf archive with object files and perf.data file to x86 laptop, the x86's perf kernel symbol resolution fails. It outputs 'unknown' for all symbols parsing. This issue is root caused by the function elf__needs_adjust_symbols(), x86 perf tool uses one weak version, Arm64 (and powerpc) has rewritten their own version. elf__needs_adjust_symbols() decides if need to parse symbols with the relative offset address; but x86 building uses the weak function which misses to check for the elf type 'ET_DYN', so that it cannot parse symbols in Arm DSOs due to the wrong result from elf__needs_adjust_symbols(). The DSO parsing should not depend on any specific architecture perf building; e.g. x86 perf tool can parse Arm and Arm64 DSOs, vice versa. And confirmed by Naveen N. Rao that powerpc64 kernels are not being built as ET_DYN anymore and change to ET_EXEC. This patch removes the arch specific functions for Arm64 and powerpc and changes elf__needs_adjust_symbols() as a common function. In the common elf__needs_adjust_symbols(), it checks an extra condition 'ET_DYN' for elf header type. With this fixing, the Arm64 DSO can be parsed properly with x86's perf tool. Before: # perf script main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c46670 [unknown] ([kernel.kallsyms]) => ffff800010c4eaec [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eaec [unknown] ([kernel.kallsyms]) => ffff800010c4eb00 [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eb08 [unknown] ([kernel.kallsyms]) => ffff800010c4e780 [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4e7a0 [unknown] ([kernel.kallsyms]) => ffff800010c4eeac [unknown] ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eebc [unknown] ([kernel.kallsyms]) => ffff800010c4ed80 [unknown] ([kernel.kallsyms]) After: # perf script main 3258 1 branches: 0 [unknown] ([unknown]) => ffff800010c4665c coresight_timeout+0x54 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c46670 coresight_timeout+0x68 ([kernel.kallsyms]) => ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eaec etm4_enable_hw+0x3cc ([kernel.kallsyms]) => ffff800010c4eb00 etm4_enable_hw+0x3e0 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eb08 etm4_enable_hw+0x3e8 ([kernel.kallsyms]) => ffff800010c4e780 etm4_enable_hw+0x60 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4e7a0 etm4_enable_hw+0x80 ([kernel.kallsyms]) => ffff800010c4eeac etm4_enable+0x2d4 ([kernel.kallsyms]) main 3258 1 branches: ffff800010c4eebc etm4_enable+0x2e4 ([kernel.kallsyms]) => ffff800010c4ed80 etm4_enable+0x1a8 ([kernel.kallsyms]) v3: Changed to check for ET_DYN across all architectures. v2: Fixed Arm64 and powerpc native building. Reported-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Allison Randal <allison@lohutok.net> Cc: Enrico Weigelt <info@metux.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: John Garry <john.garry@huawei.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.vnet.ibm.com> Link: http://lore.kernel.org/lkml/20200306015759.10084-1-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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a75af86b6f |
perf map: Set kmap->kmaps backpointer for main kernel map chunks
When a map is create to represent the main kernel area (vmlinux) with
map__new2() we allocate an extra area to store a pointer to the 'struct
maps' for the kernel maps, so that we can access that struct when
loading ELF files or kallsyms, as we will need to split it in multiple
maps, one per kernel module or ELF section (such as ".init.text").
So when map->dso->kernel is non-zero, it is expected that
map__kmap(map)->kmaps to be set to the tree of kernel maps (modules,
chunks of the main kernel, bpf progs put in place via
PERF_RECORD_KSYMBOL, the main kernel).
This was not the case when we were splitting the main kernel into chunks
for its ELF sections, which ended up making 'perf report --children'
processing a perf.data file with callchains to trip on
__map__is_kernel(), when we press ENTER to see the popup menu for main
histogram entries that starts at a symbol in the ".init.text" ELF
section, e.g.:
- 8.83% 0.00% swapper [kernel.vmlinux].init.text [k] start_kernel
start_kernel
cpu_startup_entry
do_idle
cpuidle_enter
cpuidle_enter_state
intel_idle
Fix it.
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20191218190120.GB13282@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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c54d241b35 |
perf maps: Rename map_groups.h to maps.h
One more step in the merge of 'struct maps' with 'struct map_groups'. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-9ibtn3vua76f934t7woyf26w@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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79b6bb73f8 |
perf maps: Merge 'struct maps' with 'struct map_groups'
And pick the shortest name: 'struct maps'. The split existed because we used to have two groups of maps, one for functions and one for variables, but that only complicated things, sometimes we needed to figure out what was at some address and then had to first try it on the functions group and if that failed, fall back to the variables one. That split is long gone, so for quite a while we had only one struct maps per struct map_groups, simplify things by combining those structs. First patch is the minimum needed to merge both, follow up patches will rename 'thread->mg' to 'thread->maps', etc. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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f2baa060cd |
perf symbols: Stop using map->groups, we can use kmaps instead
To test that that function is being called I just added a probe on that
place, enabled it via 'perf trace' asking for at most 16 levels of
backtraces, system wide, and then ran 'perf top' on another xterm,
voilà:
# perf probe -x ~/bin/perf dso__process_kernel_symbol
Added new event:
probe_perf:dso__process_kernel_symbol (on dso__process_kernel_symbol in /home/acme/bin/perf)
You can now use it in all perf tools, such as:
perf record -e probe_perf:dso__process_kernel_symbol -aR sleep 1
# perf trace -e probe_perf:dso__process_kernel_symbol/max-stack=16/ --max-events=2
# perf trace -e probe_perf:dso__process_kernel_symbol/max-stack=16/ --max-events=2
0.000 :17345/17345 probe_perf:dso__process_kernel_symbol(__probe_ip: 5680224)
dso__process_kernel_symbol (/home/acme/bin/perf)
dso__load_vmlinux (/home/acme/bin/perf)
dso__load_vmlinux_path (/home/acme/bin/perf)
dso__load (/home/acme/bin/perf)
map__load (/home/acme/bin/perf)
thread__find_map (/home/acme/bin/perf)
machine__resolve (/home/acme/bin/perf)
deliver_event (/home/acme/bin/perf)
__ordered_events__flush.part.0 (/home/acme/bin/perf)
process_thread (/home/acme/bin/perf)
start_thread (/usr/lib64/libpthread-2.29.so)
0.064 :17345/17345 probe_perf:dso__process_kernel_symbol(__probe_ip: 5680224)
dso__process_kernel_symbol (/home/acme/bin/perf)
dso__load_vmlinux (/home/acme/bin/perf)
dso__load_vmlinux_path (/home/acme/bin/perf)
dso__load (/home/acme/bin/perf)
map__load (/home/acme/bin/perf)
thread__find_map (/home/acme/bin/perf)
machine__resolve (/home/acme/bin/perf)
deliver_event (/home/acme/bin/perf)
__ordered_events__flush.part.0 (/home/acme/bin/perf)
process_thread (/home/acme/bin/perf)
start_thread (/usr/lib64/libpthread-2.29.so)
#
# perf stat -e probe_perf:dso__process_kernel_symbol
^C
Performance counter stats for 'system wide':
107,308 probe_perf:dso__process_kernel_symbol
8.215399813 seconds time elapsed
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5fy66x5hr5ct9pmw84jkiwvm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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32ff3fec07 |
perf copyfile: Move copyfile routines to separate files
Further reducing the util.c hodgepodge files. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-0i62zh7ok25znibyebgq0qs4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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09aa3b002c |
perf symbols: Add missing dso.h header
This was being obtained only indirectly, by luck. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-xeolxwr3iftwfw9kmw26shfe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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fb71c86cc8 |
perf tools: Remove util.h from where it is not needed
Check that it is not needed and remove, fixing up some fallout for places where it was only serving to get something else. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-9h6dg6lsqe2usyqjh5rrues4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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b1d1b094f7 |
perf symbols: Move symsrc prototypes to a separate header
So that we can remove dso.h from symbol.h and reduce the header dependency tree. Fixup cases where struct dso guts are needed but were obtained via symbol.h, indirectly. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-ip683cegt306ncu3gsz7ii21@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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9bea81b36a |
perf symbol: Move C++ demangle defines to the only file using it
No need to have it generally available in such a critical header as symbol.h. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-es1ufxv7bihiumytn5dm3drn@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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e56fbc9dc7 |
perf tools: Use list_del_init() more thorougly
To allow for destructors to check if they're operating on a object still in a list, and to avoid going from use after free list entries into still valid, or even also other already removed from list entries. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-deh17ub44atyox3j90e6rksu@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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d8f9da2404 |
perf tools: Use zfree() where applicable
In places where the equivalent was already being done, i.e.: free(a); a = NULL; And in placs where struct members are being freed so that if we have some erroneous reference to its struct, then accesses to freed members will result in segfaults, which we can detect faster than use after free to areas that may still have something seemingly valid. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-jatyoofo5boc1bsvoig6bb6i@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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7f7c536f23 |
tools lib: Adopt zalloc()/zfree() from tools/perf
Eroding a bit more the tools/perf/util/util.h hodpodge header. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-natazosyn9rwjka25tvcnyi0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |