Re: [PATCH v6 4/7] perf annotate: Do not ignore call instruction with indirect target
Em Tue, Sep 20, 2016 at 08:05:03PM +0530, Ravi Bangoria escreveu:
> On Monday 19 September 2016 09:14 PM, Arnaldo Carvalho de Melo wrote:
> > Em Fri, Aug 19, 2016 at 06:29:35PM +0530, Ravi Bangoria escreveu:
> >> Do not ignore call instruction with indirect target when its already
> >> identified as a call. This is an extension of commit e8ea1561952b
> >> ("perf annotate: Use raw form for register indirect call instructions")
> >> to generalize annotation for all instructions with indirect calls.
> >> This is needed for certain powerpc call instructions that use address
> >> in a register (such as bctrl, btarl, ...).
> >>
> >> Apart from that, when kcore is used to disassemble function, all call
> >> instructions were ignored. This patch will fix it as a side effect by
> >> not ignoring them. For example,
> >>
> >> Before (with kcore):
> >>mov%r13,%rdi
> >>callq 0x811a7e70
> >> ^ jmpq 64
> >>mov%gs:0x7ef41a6e(%rip),%al
> >>
> >> After (with kcore):
> >>mov%r13,%rdi
> >> > callq 0x811a7e70
> >> ^ jmpq 64
> >>mov%gs:0x7ef41a6e(%rip),%al
> > Ok, makes sense, but then now I have the -> and can't press enter to go
> > to that function, in fact for the case I'm using as a test, the
> > vsnprintf kernel function, I get:
> >
> >│ 56: test %al,%al
> >│ ↓ je 81
> >│ lea-0x38(%rbp),%rsi
> >│ mov%r15,%rdi
> >│ → callq 0x993e3230
> >
> > That 0x993e3230 should've been resolved to:
> >
> > [root@jouet ~]# grep 993e3230 /proc/kallsyms
> > 993e3230 t format_decode
> >
> > Trying to investigate why it doesn't...
>
> I investigated this.
>
> If this example is with kcore, then it's expected. Because, perf annotate does
> not inspect kallsyms when it can't find symbol name from disassembly itself.
>
> For example, disassembly of finish_task_switch,
Yeah, that was the case, up to yesterday, please take a look at my
perf/core branch, specifically this patch:
https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/?id=4de86ebeb433aa59764a13ce851cba08d747e0e1
I'll do that for other instructions as well, like with 'mov
$0xabcdef,%rax' that will try to resolve that address to a variable.
Will try to continue processing your (and others) patches first tho :-)
- Arnaldo
> with kcore:
>
> 810cf1b0: mov$0x1,%esi
> 810cf1b5: mov$0x4,%edi
> 810cf1ba: callq 0x811aced0
> 810cf1bf: andb $0xfb,0x4c4(%rbx)
> 810cf1c6: jmpq 0x810cf0e9
> 810cf1cb: mov%rbx,%rsi
> 810cf1ce: mov%r13,%rdi
> 810cf1d1: callq 0x811a7e70
> 810cf1d6: jmpq 0x810cf0e4
>
> with debuginfo:
> 810cf1b0: mov$0x1,%esi
> 810cf1b5: mov$0x4,%edi
> 810cf1ba: callq 811aced0 <___perf_sw_event>
> 810cf1bf: andb $0xfb,0x4c4(%rbx)
> 810cf1c6: jmpq 810cf0e9
> 810cf1cb: mov%rbx,%rsi
> 810cf1ce: mov%r13,%rdi
> 810cf1d1: callq 811a7e70 <__perf_event_task_sched_in>
> 810cf1d6: jmpq 810cf0e4
>
> call__parse tries to find symbol from angle brackets which is not present
> in case of kcore.
>
> -Ravi
>
>
> > - Arnaldo
> >
> >> Suggested-by: Michael Ellerman
> >> [Suggested about 'bctrl' instruction]
> >> Signed-off-by: Ravi Bangoria
> >> ---
> >> Changes in v6:
> >> - No change
> >>
> >> tools/perf/util/annotate.c | 8 ++--
> >> 1 file changed, 2 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> >> index ea07588..a05423b 100644
> >> --- a/tools/perf/util/annotate.c
> >> +++ b/tools/perf/util/annotate.c
> >> @@ -81,16 +81,12 @@ static int call__parse(struct ins_operands *ops, const
> >> char *norm_arch)
> >>return ops->target.name == NULL ? -1 : 0;
> >>
> >> indirect_call:
> >> - tok = strchr(endptr, '(');
> >> - if (tok != NULL) {
> >> + tok = strchr(endptr, '*');
> >> + if (tok == NULL) {
> >>ops->target.addr = 0;
> >>return 0;
> >>}
> >>
> >> - tok = strchr(endptr, '*');
> >> - if (tok == NULL)
> >> - return -1;
> >> -
> >>ops->target.addr = strtoull(tok + 1, NULL, 16);
> >>return 0;
> >> }
> >> --
> >> 2.5.5
Re: [PATCH v6 4/7] perf annotate: Do not ignore call instruction with indirect target
Hi Arnaldo,
On Monday 19 September 2016 09:14 PM, Arnaldo Carvalho de Melo wrote:
> Em Fri, Aug 19, 2016 at 06:29:35PM +0530, Ravi Bangoria escreveu:
>> Do not ignore call instruction with indirect target when its already
>> identified as a call. This is an extension of commit e8ea1561952b
>> ("perf annotate: Use raw form for register indirect call instructions")
>> to generalize annotation for all instructions with indirect calls.
>>
>> This is needed for certain powerpc call instructions that use address
>> in a register (such as bctrl, btarl, ...).
>>
>> Apart from that, when kcore is used to disassemble function, all call
>> instructions were ignored. This patch will fix it as a side effect by
>> not ignoring them. For example,
>>
>> Before (with kcore):
>>mov%r13,%rdi
>>callq 0x811a7e70
>> ^ jmpq 64
>>mov%gs:0x7ef41a6e(%rip),%al
>>
>> After (with kcore):
>>mov%r13,%rdi
>> > callq 0x811a7e70
>> ^ jmpq 64
>>mov%gs:0x7ef41a6e(%rip),%al
> Ok, makes sense, but then now I have the -> and can't press enter to go
> to that function, in fact for the case I'm using as a test, the
> vsnprintf kernel function, I get:
>
>│ 56: test %al,%al
>
> ▒
>│ ↓ je 81
>
> ▒
>│ lea-0x38(%rbp),%rsi
>
> ▒
>│ mov%r15,%rdi
>
> ▒
>│ → callq 0x993e3230
>
> That 0x993e3230 should've been resolved to:
>
> [root@jouet ~]# grep 993e3230 /proc/kallsyms
> 993e3230 t format_decode
>
> Trying to investigate why it doesn't...
I investigated this.
If this example is with kcore, then it's expected. Because, perf annotate does
not inspect kallsyms when it can't find symbol name from disassembly itself.
For example, disassembly of finish_task_switch,
with kcore:
810cf1b0: mov$0x1,%esi
810cf1b5: mov$0x4,%edi
810cf1ba: callq 0x811aced0
810cf1bf: andb $0xfb,0x4c4(%rbx)
810cf1c6: jmpq 0x810cf0e9
810cf1cb: mov%rbx,%rsi
810cf1ce: mov%r13,%rdi
810cf1d1: callq 0x811a7e70
810cf1d6: jmpq 0x810cf0e4
with debuginfo:
810cf1b0: mov$0x1,%esi
810cf1b5: mov$0x4,%edi
810cf1ba: callq 811aced0 <___perf_sw_event>
810cf1bf: andb $0xfb,0x4c4(%rbx)
810cf1c6: jmpq 810cf0e9
810cf1cb: mov%rbx,%rsi
810cf1ce: mov%r13,%rdi
810cf1d1: callq 811a7e70 <__perf_event_task_sched_in>
810cf1d6: jmpq 810cf0e4
call__parse tries to find symbol from angle brackets which is not present
in case of kcore.
-Ravi
> - Arnaldo
>
>> Suggested-by: Michael Ellerman
>> [Suggested about 'bctrl' instruction]
>> Signed-off-by: Ravi Bangoria
>> ---
>> Changes in v6:
>> - No change
>>
>> tools/perf/util/annotate.c | 8 ++--
>> 1 file changed, 2 insertions(+), 6 deletions(-)
>>
>> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
>> index ea07588..a05423b 100644
>> --- a/tools/perf/util/annotate.c
>> +++ b/tools/perf/util/annotate.c
>> @@ -81,16 +81,12 @@ static int call__parse(struct ins_operands *ops, const
>> char *norm_arch)
>> return ops->target.name == NULL ? -1 : 0;
>>
>> indirect_call:
>> -tok = strchr(endptr, '(');
>> -if (tok != NULL) {
>> +tok = strchr(endptr, '*');
>> +if (tok == NULL) {
>> ops->target.addr = 0;
>> return 0;
>> }
>>
>> -tok = strchr(endptr, '*');
>> -if (tok == NULL)
>> -return -1;
>> -
>> ops->target.addr = strtoull(tok + 1, NULL, 16);
>> return 0;
>> }
>> --
>> 2.5.5
Re: [PATCH v6 4/7] perf annotate: Do not ignore call instruction with indirect target
Em Fri, Aug 19, 2016 at 06:29:35PM +0530, Ravi Bangoria escreveu:
> Do not ignore call instruction with indirect target when its already
> identified as a call. This is an extension of commit e8ea1561952b
> ("perf annotate: Use raw form for register indirect call instructions")
> to generalize annotation for all instructions with indirect calls.
>
> This is needed for certain powerpc call instructions that use address
> in a register (such as bctrl, btarl, ...).
>
> Apart from that, when kcore is used to disassemble function, all call
> instructions were ignored. This patch will fix it as a side effect by
> not ignoring them. For example,
>
> Before (with kcore):
>mov%r13,%rdi
>callq 0x811a7e70
> ^ jmpq 64
>mov%gs:0x7ef41a6e(%rip),%al
>
> After (with kcore):
>mov%r13,%rdi
> > callq 0x811a7e70
> ^ jmpq 64
>mov%gs:0x7ef41a6e(%rip),%al
Ok, makes sense, but then now I have the -> and can't press enter to go
to that function, in fact for the case I'm using as a test, the
vsnprintf kernel function, I get:
│ 56: test %al,%al
▒
│ ↓ je 81
▒
│ lea-0x38(%rbp),%rsi
▒
│ mov%r15,%rdi
▒
│ → callq 0x993e3230
That 0x993e3230 should've been resolved to:
[root@jouet ~]# grep 993e3230 /proc/kallsyms
993e3230 t format_decode
Trying to investigate why it doesn't...
- Arnaldo
> Suggested-by: Michael Ellerman
> [Suggested about 'bctrl' instruction]
> Signed-off-by: Ravi Bangoria
> ---
> Changes in v6:
> - No change
>
> tools/perf/util/annotate.c | 8 ++--
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index ea07588..a05423b 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -81,16 +81,12 @@ static int call__parse(struct ins_operands *ops, const
> char *norm_arch)
> return ops->target.name == NULL ? -1 : 0;
>
> indirect_call:
> - tok = strchr(endptr, '(');
> - if (tok != NULL) {
> + tok = strchr(endptr, '*');
> + if (tok == NULL) {
> ops->target.addr = 0;
> return 0;
> }
>
> - tok = strchr(endptr, '*');
> - if (tok == NULL)
> - return -1;
> -
> ops->target.addr = strtoull(tok + 1, NULL, 16);
> return 0;
> }
> --
> 2.5.5
[PATCH v6 4/7] perf annotate: Do not ignore call instruction with indirect target
Do not ignore call instruction with indirect target when its already
identified as a call. This is an extension of commit e8ea1561952b
("perf annotate: Use raw form for register indirect call instructions")
to generalize annotation for all instructions with indirect calls.
This is needed for certain powerpc call instructions that use address
in a register (such as bctrl, btarl, ...).
Apart from that, when kcore is used to disassemble function, all call
instructions were ignored. This patch will fix it as a side effect by
not ignoring them. For example,
Before (with kcore):
mov%r13,%rdi
callq 0x811a7e70
^ jmpq 64
mov%gs:0x7ef41a6e(%rip),%al
After (with kcore):
mov%r13,%rdi
> callq 0x811a7e70
^ jmpq 64
mov%gs:0x7ef41a6e(%rip),%al
Suggested-by: Michael Ellerman
[Suggested about 'bctrl' instruction]
Signed-off-by: Ravi Bangoria
---
Changes in v6:
- No change
tools/perf/util/annotate.c | 8 ++--
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index ea07588..a05423b 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -81,16 +81,12 @@ static int call__parse(struct ins_operands *ops, const char
*norm_arch)
return ops->target.name == NULL ? -1 : 0;
indirect_call:
- tok = strchr(endptr, '(');
- if (tok != NULL) {
+ tok = strchr(endptr, '*');
+ if (tok == NULL) {
ops->target.addr = 0;
return 0;
}
- tok = strchr(endptr, '*');
- if (tok == NULL)
- return -1;
-
ops->target.addr = strtoull(tok + 1, NULL, 16);
return 0;
}
--
2.5.5
