[PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error

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* [PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error
@ 2019-11-27  9:56 Adrian Hunter
  2019-11-27 15:18 ` Arnaldo Carvalho de Melo
  2019-11-29  6:02 ` [tip: perf/urgent] " tip-bot2 for Adrian Hunter
  0 siblings, 2 replies; 3+ messages in thread
From: Adrian Hunter @ 2019-11-27  9:56 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo; +Cc: Jiri Olsa, linux-kernel, Andi Kleen

The 'len' returned by grab_bb() includes an extra MAXINSN bytes to allow
for the last instruction, so the the final 'offs' will not be 'len'.
Fix the error condition logic accordingly.

Before:

  $ perf record -e '{intel_pt//,cpu/mem_inst_retired.all_loads,aux-sample-size=8192/pp}:u' grep -rqs jhgjhg /boot
  [ perf record: Woken up 19 times to write data ]
  [ perf record: Captured and wrote 2.274 MB perf.data ]
  $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
            grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
        bmexec+2485:
        00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
        00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
        00005641d5806bd6                        add %rdi, %rax
        00005641d5806bd9                        movzxb  -0x1(%rax), %edx
        00005641d5806bdd                        cmp %rax, %r14
        00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
        mismatch of LBR data and executable
        00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi

After:

  $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
            grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
        bmexec+2485:
        00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
        00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
        00005641d5806bd6                        add %rdi, %rax
        00005641d5806bd9                        movzxb  -0x1(%rax), %edx
        00005641d5806bdd                        cmp %rax, %r14
        00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
        00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi
        00005641d58069c6                        add %rax, %rdi

Reported-by: Andi Kleen <ak@linux.intel.com>
Fixes: e98df280bc2a ("perf script brstackinsn: Fix recovery from LBR/binary mismatch")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/builtin-script.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index e8db26b9b29e..e2406b291c1c 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1126,7 +1126,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 				insn++;
 			}
 		}
-		if (off != (unsigned)len)
+		if (off != end - start)
 			printed += fprintf(fp, "\tmismatch of LBR data and executable\n");
 	}
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error
  2019-11-27  9:56 [PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error Adrian Hunter
@ 2019-11-27 15:18 ` Arnaldo Carvalho de Melo
  2019-11-29  6:02 ` [tip: perf/urgent] " tip-bot2 for Adrian Hunter
  1 sibling, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2019-11-27 15:18 UTC (permalink / raw)
  To: Adrian Hunter; +Cc: Jiri Olsa, linux-kernel, Andi Kleen

Em Wed, Nov 27, 2019 at 11:56:31AM +0200, Adrian Hunter escreveu:
> The 'len' returned by grab_bb() includes an extra MAXINSN bytes to allow
> for the last instruction, so the the final 'offs' will not be 'len'.
> Fix the error condition logic accordingly.
> 
> Before:
> 
>   $ perf record -e '{intel_pt//,cpu/mem_inst_retired.all_loads,aux-sample-size=8192/pp}:u' grep -rqs jhgjhg /boot
>   [ perf record: Woken up 19 times to write data ]
>   [ perf record: Captured and wrote 2.274 MB perf.data ]
>   $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
>             grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
>         bmexec+2485:
>         00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
>         00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
>         00005641d5806bd6                        add %rdi, %rax
>         00005641d5806bd9                        movzxb  -0x1(%rax), %edx
>         00005641d5806bdd                        cmp %rax, %r14
>         00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
>         mismatch of LBR data and executable
>         00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi
> 
> After:
> 
>   $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
>             grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
>         bmexec+2485:
>         00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
>         00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
>         00005641d5806bd6                        add %rdi, %rax
>         00005641d5806bd9                        movzxb  -0x1(%rax), %edx
>         00005641d5806bdd                        cmp %rax, %r14
>         00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
>         00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi
>         00005641d58069c6                        add %rax, %rdi

Thanks, applied,

- Arnaldo
 
> Reported-by: Andi Kleen <ak@linux.intel.com>
> Fixes: e98df280bc2a ("perf script brstackinsn: Fix recovery from LBR/binary mismatch")
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>  tools/perf/builtin-script.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index e8db26b9b29e..e2406b291c1c 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -1126,7 +1126,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
>  				insn++;
>  			}
>  		}
> -		if (off != (unsigned)len)
> +		if (off != end - start)
>  			printed += fprintf(fp, "\tmismatch of LBR data and executable\n");
>  	}
>  
> -- 
> 2.17.1

-- 

- Arnaldo

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [tip: perf/urgent] perf script: Fix invalid LBR/binary mismatch error
  2019-11-27  9:56 [PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error Adrian Hunter
  2019-11-27 15:18 ` Arnaldo Carvalho de Melo
@ 2019-11-29  6:02 ` tip-bot2 for Adrian Hunter
  1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Adrian Hunter @ 2019-11-29  6:02 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Andi Kleen, Adrian Hunter, Jiri Olsa, Arnaldo Carvalho de Melo,
	x86, LKML

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     5172672da02e483d9b3c4d814c3482d0c8ffb1a6
Gitweb:        https://git.kernel.org/tip/5172672da02e483d9b3c4d814c3482d0c8ffb1a6
Author:        Adrian Hunter <adrian.hunter@intel.com>
AuthorDate:    Wed, 27 Nov 2019 11:56:31 +02:00
Committer:     Arnaldo Carvalho de Melo <acme@redhat.com>
CommitterDate: Thu, 28 Nov 2019 08:08:38 -03:00

perf script: Fix invalid LBR/binary mismatch error

The 'len' returned by grab_bb() includes an extra MAXINSN bytes to allow
for the last instruction, so the the final 'offs' will not be 'len'.
Fix the error condition logic accordingly.

Before:

  $ perf record -e '{intel_pt//,cpu/mem_inst_retired.all_loads,aux-sample-size=8192/pp}:u' grep -rqs jhgjhg /boot
  [ perf record: Woken up 19 times to write data ]
  [ perf record: Captured and wrote 2.274 MB perf.data ]
  $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
            grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
        bmexec+2485:
        00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
        00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
        00005641d5806bd6                        add %rdi, %rax
        00005641d5806bd9                        movzxb  -0x1(%rax), %edx
        00005641d5806bdd                        cmp %rax, %r14
        00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
        mismatch of LBR data and executable
        00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi

After:

  $ perf script -F +brstackinsn --xed --itrace=i1usl100 | head
            grep 13759 [002]  8091.310257:       1862                                        instructions:uH:      5641d58069eb bmexec+0x86b (/bin/grep)
        bmexec+2485:
        00005641d5806b35                        jnz 0x5641d5806bd0              # MISPRED
        00005641d5806bd0                        movzxb  (%r13,%rdx,1), %eax
        00005641d5806bd6                        add %rdi, %rax
        00005641d5806bd9                        movzxb  -0x1(%rax), %edx
        00005641d5806bdd                        cmp %rax, %r14
        00005641d5806be0                        jnb 0x5641d58069c0              # MISPRED
        00005641d58069c0                        movzxb  (%r13,%rdx,1), %edi
        00005641d58069c6                        add %rax, %rdi

Fixes: e98df280bc2a ("perf script brstackinsn: Fix recovery from LBR/binary mismatch")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20191127095631.15663-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-script.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index e8db26b..e2406b2 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1126,7 +1126,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 				insn++;
 			}
 		}
-		if (off != (unsigned)len)
+		if (off != end - start)
 			printed += fprintf(fp, "\tmismatch of LBR data and executable\n");
 	}
 

^ permalink raw reply related	[flat|nested] 3+ messages in thread

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2019-11-27  9:56 [PATCH 2/2] perf script: Fix invalid LBR/binary mismatch error Adrian Hunter
2019-11-27 15:18 ` Arnaldo Carvalho de Melo
2019-11-29  6:02 ` [tip: perf/urgent] " tip-bot2 for Adrian Hunter

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