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 0xffffffff811a7e70 > >> ^ jmpq 64 > >> mov %gs:0x7ef41a6e(%rip),%al > >> > >> After (with kcore): > >> mov %r13,%rdi > >> > callq 0xffffffff811a7e70 > >> ^ 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 0xffffffff993e3230 > > > > That 0xffffffff993e3230 should've been resolved to: > > > > [root@jouet ~]# grep ffffffff993e3230 /proc/kallsyms > > ffffffff993e3230 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: > > ffffffff810cf1b0: mov $0x1,%esi > ffffffff810cf1b5: mov $0x4,%edi > ffffffff810cf1ba: callq 0xffffffff811aced0 > ffffffff810cf1bf: andb $0xfb,0x4c4(%rbx) > ffffffff810cf1c6: jmpq 0xffffffff810cf0e9 > ffffffff810cf1cb: mov %rbx,%rsi > ffffffff810cf1ce: mov %r13,%rdi > ffffffff810cf1d1: callq 0xffffffff811a7e70 > ffffffff810cf1d6: jmpq 0xffffffff810cf0e4 > > with debuginfo: > ffffffff810cf1b0: mov $0x1,%esi > ffffffff810cf1b5: mov $0x4,%edi > ffffffff810cf1ba: callq ffffffff811aced0 <___perf_sw_event> > ffffffff810cf1bf: andb $0xfb,0x4c4(%rbx) > ffffffff810cf1c6: jmpq ffffffff810cf0e9 <finish_task_switch+0x69> > ffffffff810cf1cb: mov %rbx,%rsi > ffffffff810cf1ce: mov %r13,%rdi > ffffffff810cf1d1: callq ffffffff811a7e70 <__perf_event_task_sched_in> > ffffffff810cf1d6: jmpq ffffffff810cf0e4 <finish_task_switch+0x64> > > call__parse tries to find symbol from angle brackets which is not present > in case of kcore. > > -Ravi > > > > - Arnaldo > > > >> Suggested-by: Michael Ellerman <m...@ellerman.id.au> > >> [Suggested about 'bctrl' instruction] > >> Signed-off-by: Ravi Bangoria <ravi.bango...@linux.vnet.ibm.com> > >> --- > >> 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
