Messages in this thread | | | Date | Wed, 3 Apr 2019 15:53:05 -0500 | From | Josh Poimboeuf <> | Subject | Re: linux-next: Tree for Apr 3 (objtool) |
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On Wed, Apr 03, 2019 at 08:02:43AM -0700, Randy Dunlap wrote: > On 4/3/19 1:24 AM, Stephen Rothwell wrote: > > Hi all, > > > > Changes since 20190402: > > > > on x86_64: > > arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0x909: unreachable instruction
Your .o file looks odd. I can't recreate the issue when I build the same object.
Did the issue only just now show up? Can you bisect it? What version of binutils are you using?
Here's the disassembly:
------------------ 903: e8 00 00 00 00 callq 908 <interrupt_entry+0xc8> 904: R_X86_64_PC32 trace_hardirqs_off_thunk-0x4 908: c3 retq 909: eb 75 jmp 980 <common_interrupt> 90b: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 912: 00 00 00 00 916: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 91d: 00 00 00 00 921: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 928: 00 00 00 00 92c: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 933: 00 00 00 00 937: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 93e: 00 00 00 00 942: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 949: 00 00 00 00 94d: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 954: 00 00 00 00 958: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 95f: 00 00 00 00 963: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 96a: 00 00 00 00 96e: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 975: 00 00 00 00 979: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
0000000000000980 <common_interrupt>: ------------------
Where the heck does that "jmp 980" come from? I don't see it in the code:
------------------ ENTRY(interrupt_entry) .... TRACE_IRQS_OFF
ret END(interrupt_entry) _ASM_NOKPROBE(interrupt_entry)
/* Interrupt entry/exit. */
/* * The interrupt stubs push (~vector+0x80) onto the stack and * then jump to common_interrupt. */ .p2align CONFIG_X86_L1_CACHE_SHIFT common_interrupt: ------------------
Hopefully gas isn't inserting stray jumps for code alignments...
-- Josh
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