| Message ID | 1480953407-7605-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi Arnaldo,
Hmm, so it's difficult to find example of this when we use debuginfo.
Because...
Jump__parse tries to look for two things 'offset' and 'target address'.
objdump with debuginfo will include offset in assembly f.e. annotate of
'smp_call_function_single' with perf.data and vmlinux I shared.
│c00000000016d6ac: cmpwi cr7,r9,0 ▒
│c00000000016d6b0: ↑ bne cr7,c00000000016d59c <.smp_call_function_single+0x8c> ▒
│c00000000016d6b4: addis r10,r2,-15 ▒
objdump of same function with kcore.
│c00000000016d6ac: cmpwi cr7,r9,0 ▒
│c00000000016d6b0: ↓ bne cr7,0xc00000000016d59c ▒
│c00000000016d6b4: addis r10,r2,-15 ▒
Annotating in first case won't show any issue because we directly get
offset. But in this case as well, we are parsing wrong target address
in ops->target.addr
While we don't have offset in second case, we use target address to
find it. And thus it shows wrong o/p something like:
│ cmpwi cr7,r9,0 ▒
│ ↓ bne 3fffffffffe92afc ▒
│ addis r10,r2,-15 ▒
BTW, we have lot of such instructions in kernel.
Thanks,
-Ravi
On Monday 05 December 2016 09:26 PM, Ravi Bangoria wrote:
> Arch like powerpc has jump instructions that includes target address
> as second operand. For example, 'bne cr7,0xc0000000000f6154'. Add
> support for such instruction in perf annotate.
>
> objdump o/p:
> c0000000000f6140: ld r9,1032(r31)
> c0000000000f6144: cmpdi cr7,r9,0
> c0000000000f6148: bne cr7,0xc0000000000f6154
> c0000000000f614c: ld r9,2312(r30)
> c0000000000f6150: std r9,1032(r31)
> c0000000000f6154: ld r9,88(r31)
>
> Corresponding perf annotate o/p:
>
> Before patch:
> ld r9,1032(r31)
> cmpdi cr7,r9,0
> v bne 3ffffffffff09f2c
> ld r9,2312(r30)
> std r9,1032(r31)
> 74: ld r9,88(r31)
>
> After patch:
> ld r9,1032(r31)
> cmpdi cr7,r9,0
> v bne 74
> ld r9,2312(r30)
> std r9,1032(r31)
> 74: ld r9,88(r31)
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
> ---
> Changes in v8:
> - v7: https://lkml.org/lkml/2016/9/21/436
> - Rebase to acme/perf/core
> - Little change in patch description.
> - No logical changes. (Cross arch annotate patches are in. This patch
> is for hardening annotate for powerpc.)
>
> tools/perf/util/annotate.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index ea7e0de..590244e 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -223,8 +223,12 @@ bool ins__is_call(const struct ins *ins)
> static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map *map __maybe_unused)
> {
> const char *s = strchr(ops->raw, '+');
> + const char *c = strchr(ops->raw, ',');
>
> - ops->target.addr = strtoull(ops->raw, NULL, 16);
> + if (c++ != NULL)
> + ops->target.addr = strtoull(c, NULL, 16);
> + else
> + ops->target.addr = strtoull(ops->raw, NULL, 16);
>
> if (s++ != NULL)
> ops->target.offset = strtoull(s, NULL, 16);
Em Mon, Dec 05, 2016 at 09:26:46PM +0530, Ravi Bangoria escreveu: > +++ b/tools/perf/util/annotate.c > @@ -223,8 +223,12 @@ bool ins__is_call(const struct ins *ins) > static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map *map __maybe_unused) > { > const char *s = strchr(ops->raw, '+'); > + const char *c = strchr(ops->raw, ','); > > - ops->target.addr = strtoull(ops->raw, NULL, 16); > + if (c++ != NULL) > + ops->target.addr = strtoull(c, NULL, 16); > + else > + ops->target.addr = strtoull(ops->raw, NULL, 16); > > if (s++ != NULL) > ops->target.offset = strtoull(s, NULL, 16); Simple enough, applied. - Arnaldo
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index ea7e0de..590244e 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -223,8 +223,12 @@ bool ins__is_call(const struct ins *ins) static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map *map __maybe_unused) { const char *s = strchr(ops->raw, '+'); + const char *c = strchr(ops->raw, ','); - ops->target.addr = strtoull(ops->raw, NULL, 16); + if (c++ != NULL) + ops->target.addr = strtoull(c, NULL, 16); + else + ops->target.addr = strtoull(ops->raw, NULL, 16); if (s++ != NULL) ops->target.offset = strtoull(s, NULL, 16);
Arch like powerpc has jump instructions that includes target address as second operand. For example, 'bne cr7,0xc0000000000f6154'. Add support for such instruction in perf annotate. objdump o/p: c0000000000f6140: ld r9,1032(r31) c0000000000f6144: cmpdi cr7,r9,0 c0000000000f6148: bne cr7,0xc0000000000f6154 c0000000000f614c: ld r9,2312(r30) c0000000000f6150: std r9,1032(r31) c0000000000f6154: ld r9,88(r31) Corresponding perf annotate o/p: Before patch: ld r9,1032(r31) cmpdi cr7,r9,0 v bne 3ffffffffff09f2c ld r9,2312(r30) std r9,1032(r31) 74: ld r9,88(r31) After patch: ld r9,1032(r31) cmpdi cr7,r9,0 v bne 74 ld r9,2312(r30) std r9,1032(r31) 74: ld r9,88(r31) Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> --- Changes in v8: - v7: https://lkml.org/lkml/2016/9/21/436 - Rebase to acme/perf/core - Little change in patch description. - No logical changes. (Cross arch annotate patches are in. This patch is for hardening annotate for powerpc.) tools/perf/util/annotate.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)