The following commit has been merged into the objtool/core branch of tip:
Commit-ID: ac27ecf68a1ada240bb71531dc2d30cde04ad70a
Gitweb: https://git.kernel.org/tip/ac27ecf68a1ada240bb71531dc2d30cde04ad70a
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Tue, 30 May 2023 16:07:41 -07:00
Committer: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
CommitterDate: Wed, 07 Jun 2023 09:54:45 -07:00
x86/entry: Move thunk restore code into thunk functions
There's no need for both thunk functions to jump to the same shared
thunk restore code which lives outside the thunk function boundaries.
It disrupts i-cache locality and confuses objtool. Keep it simple by
keeping each thunk's restore code self-contained within the function.
Fixes a bunch of false positive "missing __noreturn" warnings like:
vmlinux.o: warning: objtool: do_arch_prctl_common+0xf4: preempt_schedule_thunk() is missing a __noreturn annotation
Fixes: fedb724c3db5 ("objtool: Detect missing __noreturn annotations")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202305281037.3PaI3tW4-lkp@xxxxxxxxx/
Link: https://lore.kernel.org/r/46aa8aeb716f302e22e1673ae15ee6fe050b41f4.1685488050.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/entry/thunk_64.S | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index 5e37f41..27b5da2 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -26,17 +26,7 @@ SYM_FUNC_START(\name)
pushq %r11
call \func
- jmp __thunk_restore
-SYM_FUNC_END(\name)
- _ASM_NOKPROBE(\name)
- .endm
-
- THUNK preempt_schedule_thunk, preempt_schedule
- THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
- EXPORT_SYMBOL(preempt_schedule_thunk)
- EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
-SYM_CODE_START_LOCAL(__thunk_restore)
popq %r11
popq %r10
popq %r9
@@ -48,5 +38,11 @@ SYM_CODE_START_LOCAL(__thunk_restore)
popq %rdi
popq %rbp
RET
- _ASM_NOKPROBE(__thunk_restore)
-SYM_CODE_END(__thunk_restore)
+SYM_FUNC_END(\name)
+ _ASM_NOKPROBE(\name)
+ .endm
+
+THUNK preempt_schedule_thunk, preempt_schedule
+THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
+EXPORT_SYMBOL(preempt_schedule_thunk)
+EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
|