[PATCH] perf annotate: fix parsing aarch64 branch instructions after objdump update
From: acme@kernel.org (Arnaldo Carvalho de Melo)
Date: 2018-08-27 12:50:56
Also in:
linux-perf-users, lkml
Em Thu, Aug 23, 2018 at 07:10:47PM -0500, Kim Phillips escreveu:
quoted hunk ↗ jump to hunk
Starting with binutils 2.28, aarch64 objdump adds comments to the disassembly output to show the alternative names of a condition code [1]. It is assumed that commas in objdump comments could occur in other arches now or in the future, so this fix is arch-independent. The fix could have been done with arm64 specific jump__parse and jump__scnprintf functions, but the jump__scnprintf instruction would have to have its comment character be a literal, since the scnprintf functions cannot receive a struct arch easily. This inconvenience also applies to the generic jump__scnprintf, which is why we add a raw_comment pointer to struct ins_operands, so the __parse function assigns it to be re-used by its corresponding __scnprintf function. Example differences in 'perf annotate --stdio2' output on an aarch64 perf.data file: BEFORE: ? b.cs ffff200008133d1c <unwind_frame+0x18c> // b.hs, dffff7ecc47b AFTER : ? b.cs 18c BEFORE: ? b.cc ffff200008d8d9cc <get_alloc_profile+0x31c> // b.lo, b.ul, dffff727295b AFTER : ? b.cc 31c The branch target labels 18c and 31c also now appear in the output: BEFORE: add x26, x29, #0x80 AFTER : 18c: add x26, x29, #0x80 BEFORE: add x21, x21, #0x8 AFTER : 31c: add x21, x21, #0x8 The Fixes: tag below is added so stable branches will get the update; it doesn't necessarily mean that commit was broken at the time, rather it didn't withstand the aarch64 objdump update. Tested no difference in output for sample x86_64, power arch perf.data files. [1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=bb7eff5206e4795ac79c177a80fe9f4630aaf730 Cc: Ravi Bangoria <redacted> Cc: Anton Blanchard <redacted> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Christian Borntraeger <redacted> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Taeung Song <redacted> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <redacted> Cc: Namhyung Kim <namhyung@kernel.org> Fixes: b13bbeee5ee6 ("perf annotate: Fix branch instruction with multiple operands") Signed-off-by: Kim Phillips <redacted> --- tools/perf/util/annotate.c | 17 ++++++++++++++++- tools/perf/util/annotate.h | 1 + 2 files changed, 17 insertions(+), 1 deletion(-)diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index e32ead4744bd..b83897dafbb0 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c@@ -282,7 +282,8 @@ bool ins__is_call(const struct ins *ins) return ins->ops == &call_ops || ins->ops == &s390_call_ops; } -static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *ops, struct map_symbol *ms) +static int jump__parse(struct arch *arch, struct ins_operands *ops, + struct map_symbol *ms)
Try to refrain from reflowing, what you need to do here is just to remove that __maybe_unused.
quoted hunk ↗ jump to hunk
{ struct map *map = ms->map; struct symbol *sym = ms->sym;@@ -291,6 +292,15 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op }; const char *c = strchr(ops->raw, ','); u64 start, end; + + /* + * Prevent from matching commas in the comment section, e.g.: + * ffff200008446e70: b.cs ffff2000084470f4 <generic_exec_single+0x314> // b.hs, b.nlast + */ + ops->raw_comment = strchr(ops->raw, arch->objdump.comment_char); + if (c && ops->raw_comment && c > ops->raw_comment) + c = NULL; + /* * Examples of lines to parse for the _cpp_lex_token@@Base * function:@@ -367,6 +377,11 @@ static int jump__scnprintf(struct ins *ins, char *bf, size_t size, return scnprintf(bf, size, "%-6s %s", ins->name, ops->target.sym->name); c = strchr(ops->raw, ','); + + /* Prevent from matching commas in the comment section */ + if (ops->raw_comment && c && c > ops->raw_comment) + c = NULL;
This is equivalent to the previous test, but why do it differently?
Since both are open coded equivalents, why not do something like:
c = validate_comma(c, ops);
That would translate to:
static inline const char *validate_comma(const char *c, ops)
{
return c > ops->raw_comment ? NULL : c;
}
Which should be a third equivalent form to check if c, having been
found, is after ops->raw_comment, if there is a raw_comment?
- Arnaldo
quoted hunk ↗ jump to hunk
+ if (c != NULL) { const char *c2 = strchr(c + 1, ',');diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h index 005a5fe8a8c6..5399ba2321bb 100644 --- a/tools/perf/util/annotate.h +++ b/tools/perf/util/annotate.h@@ -22,6 +22,7 @@ struct ins { struct ins_operands { char *raw; + char *raw_comment; struct { char *raw; char *name;-- 2.17.1