diff options
Diffstat (limited to 'tools/objtool/Documentation/objtool.txt')
| -rw-r--r-- | tools/objtool/Documentation/objtool.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt index fe39c2a8ef0d..7c3ee959b63c 100644 --- a/tools/objtool/Documentation/objtool.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -284,6 +284,25 @@ the objtool maintainers. Otherwise the stack frame may not get created before the call. + objtool can help with pinpointing the exact function where it happens: + + $ OBJTOOL_ARGS="--verbose" make arch/x86/kvm/ + + arch/x86/kvm/kvm.o: warning: objtool: .altinstr_replacement+0xc5: call without frame pointer save/setup + arch/x86/kvm/kvm.o: warning: objtool: em_loop.part.0+0x29: (alt) + arch/x86/kvm/kvm.o: warning: objtool: em_loop.part.0+0x0: <=== (sym) + LD [M] arch/x86/kvm/kvm-intel.o + 0000 0000000000028220 <em_loop.part.0>: + 0000 28220: 0f b6 47 61 movzbl 0x61(%rdi),%eax + 0004 28224: 3c e2 cmp $0xe2,%al + 0006 28226: 74 2c je 28254 <em_loop.part.0+0x34> + 0008 28228: 48 8b 57 10 mov 0x10(%rdi),%rdx + 000c 2822c: 83 f0 05 xor $0x5,%eax + 000f 2822f: 48 c1 e0 04 shl $0x4,%rax + 0013 28233: 25 f0 00 00 00 and $0xf0,%eax + 0018 28238: 81 e2 d5 08 00 00 and $0x8d5,%edx + 001e 2823e: 80 ce 02 or $0x2,%dh + ... 2. file.o: warning: objtool: .text+0x53: unreachable instruction |