In annotate_browser__mark_jump_targets
702 dlt = browser->offsets[dl->ops.target];
703 bdlt = disasm_line__browser(dlt);
704 bdlt->jump_target = true;
705 }
706
707 }
(gdb) p size
$5 = 2415
(gdb) p offset
$6 = 140
(gdb) p dl->ops.target
$7 = 143
(gdb) p browser->offsets[143]
$8 = (struct disasm_line *) 0x0
(gdb) p dl->name
$9 = 0x2363bd0 "je"
(gdb)
Really strange, the code assumed that at the jump target we would have
an assembly line, but only in the previous instruction offset we have a
'lock':
(gdb) p browser->offsets[144]
$10 = (struct disasm_line *) 0x0
(gdb) p browser->offsets[142]
$11 = (struct disasm_line *) 0x27bd620
(gdb) p browser->offsets[142]->name
$12 = 0x237a8a0 "lock"
(gdb)
I'll study this more, but for now I'll just check if there is a
disasm_line at dl->ops.target, i.e. a valid jump target.
Reported-by: Hagen Paul Pfeifer <hagen@jauu.net>
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-inzjrzyqhkzyv78met2vula6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Simple algorithm, just look for the next backward jump that points to
before the cursor.
Then draw an arrow connecting the jump to its target.
Do this as you move the cursor, entering/exiting possible loops.
Ex (graph chars replaced to avoid mail encoding woes):
avc_has_perm_flags
0.00 | nopl 0x0(%rax)
5.36 |+-> 68: mov (%rax),%rax
5.15 || test %rax,%rax
0.00 || v je 130
2.96 || 74: cmp -0x20(%rax),%ebx
47.38 || lea -0x20(%rax),%rcx
0.28 || ^ jne 68
3.16 || cmp -0x18(%rax),%dx
0.00 |+------^ jne 68
4.92 | cmp 0x4(%rcx),%r13d
0.00 | v jne 68
1.15 | test %rcx,%rcx
0.00 | v je 130
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5gairf6or7dazlx3ocxwvftm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We need to cope with things like:
$ objdump -d --no-show-raw -S -C /lib/modules/3.4.0-rc2+/build/vmlinux
<SNIP>
ffffffff8125ec60 <copy_user_generic_unrolled>:
* Output:
* eax uncopied bytes or 0 if successful.
*/
ENTRY(copy_user_generic_unrolled)
CFI_STARTPROC
cmpl $8,%edx
ffffffff8125ec60: cmp $0x8,%edx
jb 20f /* less then 8 bytes, go to byte copy loop */
ffffffff8125ec63: jb ffffffff8125ecf5 <copy_user_generic_unrolled+0x95>
ALIGN_DESTINATION
<SNIP>
ffffffff8125ec8d: je ffffffff8125ecd9 <copy_user_generic_unrolled+0x79>
1: movq (%rsi),%r8
ffffffff8125ec8f: mov (%rsi),%r8
2: movq 1*8(%rsi),%r9
ffffffff8125ec92: mov 0x8(%rsi),%r9
3: movq 2*8(%rsi),%r10
ffffffff8125ec96: mov 0x10(%rsi),%r10
4: movq 3*8(%rsi),%r11
<SNIP>
Probably expect that the length of the addr field be the same...
Lazy move for now, back to supporting suppressing the address on callq lines...
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-7hp85vnvowpqj8799f8rxbu1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
And implement the jump one, where if the operands string is not passed,
a compact form that uses just the target address is used.
Right now this is toggled via the 'o' option in the annotate browser,
switching from:
0.00 : ffffffff811661e8: je ffffffff81166204 <mem_cgroup_count_vm_event+0x44>
0.00 : ffffffff811661ea: cmp $0xb,%esi
0.00 : ffffffff811661ed: je ffffffff811661f8 <mem_cgroup_count_vm_event+0x38>
To:
0.00 : 28: je 44
0.00 : 2a: cmp $0xb,%esi
0.00 : 2d: je 38
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-o88q46yh4kxgpd1chk5gvjl5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
