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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug debug/98776] DW_AT_low_pc is inconsistent with function entry address, when enabling -fpatchable-function-entry
Date: Wed, 30 Jun 2021 06:28:06 +0000 [thread overview]
Message-ID: <bug-98776-4-xOx2gbplvW@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98776-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98776
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2021-06-30
Ever confirmed|0 |1
Known to work| |11.1.0
CC| |rguenth at gcc dot gnu.org
Known to fail| |10.3.0
Target|x86,arm64 |x86_64-*-* aarch64
Status|UNCONFIRMED |NEW
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.
void __attribute__((noipa)) foo() { }
int main() { foo (); }
> gcc-10 t.c -g -fpatchable-function-entry=16 -O
> gdb ./a.out
GNU gdb (GDB; SUSE Linux Enterprise 15) 10.1
...
(gdb) disassemble foo
Dump of assembler code for function foo:
0x00000000004004a6 <+0>: ret
End of assembler dump.
(gdb) b foo
Breakpoint 1 at 0x400496 (2 locations)
so the symbol is at 0x400496 but low-pc is 0x4004a6
On trunk the FDE start/end labels look correct:
foo:
.LFB0:
.cfi_startproc
.section __patchable_function_entries,"awo",@progbits,foo
.align 8
.quad .LPFE1
.text
.LPFE1:
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
ret
.cfi_endproc
.LFE0:
and it seems to work there. Quick verification shows it works with GCC 11+
but fails with GCC 10 which has
foo:
.section __patchable_function_entries,"aw",@progbits
.align 8
.quad .LPFE1
.text
.LPFE1:
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
.LFB0:
.file 1 "t.c"
.loc 1 1 35 view -0
.cfi_startproc
.loc 1 1 37 view .LVU1
ret
.cfi_endproc
.LFE0:
.size foo, .-foo
next prev parent reply other threads:[~2021-06-30 6:28 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 6:32 [Bug debug/98776] New: " lvlin at mail dot ustc.edu.cn
2021-03-31 10:21 ` [Bug debug/98776] " rearnsha at gcc dot gnu.org
2021-06-29 17:06 ` luis.machado at linaro dot org
2021-06-30 6:28 ` rguenth at gcc dot gnu.org [this message]
2021-06-30 6:28 ` rguenth at gcc dot gnu.org
2021-06-30 7:12 ` marxin at gcc dot gnu.org
2021-06-30 8:06 ` rguenth at gcc dot gnu.org
2021-06-30 8:20 ` marxin at gcc dot gnu.org
2021-06-30 8:27 ` rguenth at gcc dot gnu.org
2022-09-29 20:50 ` spop at gcc dot gnu.org
2022-12-01 3:11 ` spop at gcc dot gnu.org
2022-12-08 17:12 ` cvs-commit at gcc dot gnu.org
2022-12-15 15:08 ` cvs-commit at gcc dot gnu.org
2022-12-15 15:10 ` cvs-commit at gcc dot gnu.org
2022-12-15 15:12 ` cvs-commit at gcc dot gnu.org
2022-12-15 15:15 ` spop at gcc dot gnu.org
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