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Subject[PATCH 41/44] perf annotate: Add "_local" to jump/offset validation routines
Date
From: Arnaldo Carvalho de Melo <acme@redhat.com>

Because they all really check if we can access data structures/visual
constructs where a "jump" instruction targets code in the same function,
i.e. things like:

__pthread_mutex_lock /usr/lib64/libpthread-2.26.so
1.95 │ mov __pthread_force_elision,%ecx
│ ┌──test %ecx,%ecx
0.07 │ ├──je 60
│ │ test $0x300,%esi
│ │↓ jne 60
│ │ or $0x100,%esi
│ │ mov %esi,0x10(%rdi)
│ 42:│ mov %esi,%edx
│ │ lea 0x16(%r8),%rsi
│ │ mov %r8,%rdi
│ │ and $0x80,%edx
│ │ add $0x8,%rsp
│ │→ jmpq __lll_lock_elision
│ │ nop
0.29 │ 60:└─→and $0x80,%esi
0.07 │ mov $0x1,%edi
0.29 │ xor %eax,%eax
2.53 │ lock cmpxchg %edi,(%r8)

And not things like that "jmpq __lll_lock_elision", that instead should behave
like a "call" instruction and "jump" to the disassembly of "___lll_lock_elision".

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-3cwx39u3h66dfw9xjrlt7ca2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/ui/browsers/annotate.c | 2 +-
tools/perf/util/annotate.c | 9 ++++-----
tools/perf/util/annotate.h | 14 +++++++++++---
3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index 3834b264ba41..d77896a99570 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -155,7 +155,7 @@ static void annotate_browser__draw_current_jump(struct ui_browser *browser)
if (strstr(sym->name, "@plt"))
return;

- if (!disasm_line__is_valid_jump(cursor, sym))
+ if (!disasm_line__is_valid_local_jump(cursor, sym))
return;

/*
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index c299881c640a..9524f322f597 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1409,7 +1409,7 @@ static int symbol__parse_objdump_line(struct symbol *sym, FILE *file,
if (dl == NULL)
return -1;

- if (!disasm_line__has_offset(dl)) {
+ if (!disasm_line__has_local_offset(dl)) {
dl->ops.target.offset = dl->ops.target.addr -
map__rip_2objdump(map, sym->start);
dl->ops.target.offset_avail = true;
@@ -2176,11 +2176,10 @@ size_t disasm__fprintf(struct list_head *head, FILE *fp)
return printed;
}

-
-bool disasm_line__is_valid_jump(struct disasm_line *dl, struct symbol *sym)
+bool disasm_line__is_valid_local_jump(struct disasm_line *dl, struct symbol *sym)
{
if (!dl || !dl->ins.ops || !ins__is_jump(&dl->ins) ||
- !disasm_line__has_offset(dl) || dl->ops.target.offset < 0 ||
+ !disasm_line__has_local_offset(dl) || dl->ops.target.offset < 0 ||
dl->ops.target.offset >= (s64)symbol__size(sym))
return false;

@@ -2201,7 +2200,7 @@ void annotation__mark_jump_targets(struct annotation *notes, struct symbol *sym)

dl = disasm_line(al);

- if (!disasm_line__is_valid_jump(dl, sym))
+ if (!disasm_line__is_valid_local_jump(dl, sym))
continue;

al = notes->offsets[dl->ops.target.offset];
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index ad8baafaf9f9..ff7e3df31efa 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -117,12 +117,20 @@ static inline struct disasm_line *disasm_line(struct annotation_line *al)
return al ? container_of(al, struct disasm_line, al) : NULL;
}

-static inline bool disasm_line__has_offset(const struct disasm_line *dl)
+/*
+ * Is this offset in the same function as the line it is used?
+ * asm functions jump to other functions, for instance.
+ */
+static inline bool disasm_line__has_local_offset(const struct disasm_line *dl)
{
- return dl->ops.target.offset_avail;
+ return dl->ops.target.offset_avail && !dl->ops.target.outside;
}

-bool disasm_line__is_valid_jump(struct disasm_line *dl, struct symbol *sym);
+/*
+ * Can we draw an arrow from the jump to its target, for instance? I.e.
+ * is the jump and its target in the same function?
+ */
+bool disasm_line__is_valid_local_jump(struct disasm_line *dl, struct symbol *sym);

void disasm_line__free(struct disasm_line *dl);
struct annotation_line *
--
2.14.3
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