Subject: [PATCH 15/29] perf annotate: Fix jump target outside of function address range

From: Arnaldo Carvalho de Melo <[email-masked]>
Date: Tue, 20 Dec 2016 14:03:44 -0300

From: Ravi Bangoria <[email-masked]>

If jump target is outside of function range, perf is not handling it
correctly. Especially when target address is lesser than function start
address, target offset will be negative. But, target address declared to
be unsigned, converts negative number into 2's complement. See below
example. Here target of 'jumpq' instruction at 34cf8 is 34ac0 which is
lesser than function start address(34cf0).

        34ac0 - 34cf0 = -0x230 = 0xfffffffffffffdd0

Objdump output:

  0000000000034cf0 <__sigaction>:
  __GI___sigaction():
    34cf0: lea    -0x20(%rdi),%eax
    34cf3: cmp    -bashx1,%eax
    34cf6: jbe    34d00 <__sigaction+0x10>
    34cf8: jmpq   34ac0 <__GI___libc_sigaction>
    34cfd: nopl   (%rax)
    34d00: mov    0x386161(%rip),%rax        # 3bae68 <_DYNAMIC+0x2e8>
    34d07: movl   -bashx16,%fs:(%rax)
    34d0e: mov    -bashxffffffff,%eax
    34d13: retq

perf annotate before applying patch:

  __GI___sigaction  /usr/lib64/libc-2.22.so
           lea    -0x20(%rdi),%eax
           cmp    -bashx1,%eax
        v  jbe    10
        v  jmpq   fffffffffffffdd0
           nop
    10:    mov    _DYNAMIC+0x2e8,%rax
           movl   -bashx16,%fs:(%rax)
           mov    -bashxffffffff,%eax
           retq

perf annotate after applying patch:

  __GI___sigaction  /usr/lib64/libc-2.22.so
           lea    -0x20(%rdi),%eax
           cmp    -bashx1,%eax
        v  jbe    10
        ^  jmpq   34ac0 <__GI___libc_sigaction>
           nop
    10:    mov    _DYNAMIC+0x2e8,%rax
           movl   -bashx16,%fs:(%rax)
           mov    -bashxffffffff,%eax
           retq

Signed-off-by: Ravi Bangoria <[email-masked]>
Cc: Alexander Shishkin <[email-masked]>
Cc: Chris Riyder <[email-masked]>
Cc: Kim Phillips <[email-masked]>
Cc: Markus Trippelsdorf <[email-masked]>
Cc: Masami Hiramatsu <[email-masked]>
Cc: Naveen N. Rao <[email-masked]>
Cc: Peter Zijlstra <[email-masked]>
Cc: Taeung Song <[email-masked]>
Cc: [email-masked]
Link: http://lkml.kernel.org/r/[email-masked]
Signed-off-by: Arnaldo Carvalho de Melo <[email-masked]>
---
 tools/perf/ui/browsers/annotate.c |  5 +++--
 tools/perf/util/annotate.c        | 14 +++++++++-----
 tools/perf/util/annotate.h        |  5 +++--
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index ec7a30fad149..ba36aac340bc 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -215,7 +215,7 @@ static void annotate_browser__write(struct ui_browser *browser, void *entry, int
 			ui_browser__set_color(browser, color);
 		if (dl->ins.ops && dl->ins.ops->scnprintf) {
 			if (ins__is_jump(&dl->ins)) {
-				bool fwd = dl->ops.target.offset > (u64)dl->offset;
+				bool fwd = dl->ops.target.offset > dl->offset;
 
 				ui_browser__write_graph(browser, fwd ? SLSMG_DARROW_CHAR :
 								    SLSMG_UARROW_CHAR);
@@ -245,7 +245,8 @@ static bool disasm_line__is_valid_jump(struct disasm_line *dl, struct symbol *sy
 {
 	if (!dl || !dl->ins.ops || !ins__is_jump(&dl->ins)
 	    || !disasm_line__has_offset(dl)
-	    || dl->ops.target.offset >= symbol__size(sym))
+	    || dl->ops.target.offset < 0
+	    || dl->ops.target.offset >= (s64)symbol__size(sym))
 		return false;
 
 	return true;
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 590244e5781e..c81a3950a7fe 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -230,10 +230,12 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 	else
 		ops->target.addr = strtoull(ops->raw, NULL, 16);
 
-	if (s++ != NULL)
+	if (s++ != NULL) {
 		ops->target.offset = strtoull(s, NULL, 16);
-	else
-		ops->target.offset = UINT64_MAX;
+		ops->target.offset_avail = true;
+	} else {
+		ops->target.offset_avail = false;
+	}
 
 	return 0;
 }
@@ -241,7 +243,7 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
 			   struct ins_operands *ops)
 {
-	if (!ops->target.addr)
+	if (!ops->target.addr || ops->target.offset < 0)
 		return ins__raw_scnprintf(ins, bf, size, ops);
 
 	return scnprintf(bf, size, "%-6.6s %" PRIx64, ins->name, ops->target.offset);
@@ -1209,9 +1211,11 @@ static int symbol__parse_objdump_line(struct symbol *sym, struct map *map,
 	if (dl == NULL)
 		return -1;
 
-	if (dl->ops.target.offset == UINT64_MAX)
+	if (!disasm_line__has_offset(dl)) {
 		dl->ops.target.offset = dl->ops.target.addr -
 					map__rip_2objdump(map, sym->start);
+		dl->ops.target.offset_avail = true;
+	}
 
 	/* kcore has no symbols, so add the call target name */
 	if (dl->ins.ops && ins__is_call(&dl->ins) && !dl->ops.target.name) {
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 87e4cadc5d27..09776b5af991 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -24,7 +24,8 @@ struct ins_operands {
 		char	*raw;
 		char	*name;
 		u64	addr;
-		u64	offset;
+		s64	offset;
+		bool	offset_avail;
 	} target;
 	union {
 		struct {
@@ -68,7 +69,7 @@ struct disasm_line {
 
 static inline bool disasm_line__has_offset(const struct disasm_line *dl)
 {
-	return dl->ops.target.offset != UINT64_MAX;
+	return dl->ops.target.offset_avail;
 }
 
 void disasm_line__free(struct disasm_line *dl);
-- 
2.9.3