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 <ravi.bangoria@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Chris Riyder <chris.ryder@arm.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1480953407-7605-3-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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);
{
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;
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;
}
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);
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) {
char *raw;
char *name;
u64 addr;
- u64 offset;
+ s64 offset;
+ bool offset_avail;
} target;
union {
struct {
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);