diff options
| author | Andrea Righi <andrea.righi@canonical.com> | 2022-07-14 10:49:15 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-21 16:16:13 +0300 |
| commit | a9943942a501114d5ea1093329e3b04da597b085 (patch) | |
| tree | 20d119b377a9c183c2e02974ee335e3446203600 /arch | |
| parent | e6c228b950d0f7304bb54b240662308fceef513c (diff) | |
| download | linux-a9943942a501114d5ea1093329e3b04da597b085.tar.xz | |
x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y
[ Upstream commit de979c83574abf6e78f3fa65b716515c91b2613d ]
With CONFIG_PREEMPTION disabled, arch/x86/entry/thunk_$(BITS).o becomes
an empty object file.
With some old versions of binutils (i.e., 2.35.90.20210113-1ubuntu1) the
GNU assembler doesn't generate a symbol table for empty object files and
objtool fails with the following error when a valid symbol table cannot
be found:
arch/x86/entry/thunk_64.o: warning: objtool: missing symbol table
To prevent this from happening, build thunk_$(BITS).o only if
CONFIG_PREEMPTION is enabled.
BugLink: https://bugs.launchpad.net/bugs/1911359
Fixes: 320100a5ffe5 ("x86/entry: Remove the TRACE_IRQS cruft")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/Ys/Ke7EWjcX+ZlXO@arighi-desktop
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/entry/Makefile | 3 | ||||
| -rw-r--r-- | arch/x86/entry/thunk_32.S | 2 | ||||
| -rw-r--r-- | arch/x86/entry/thunk_64.S | 4 | ||||
| -rw-r--r-- | arch/x86/um/Makefile | 3 |
4 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile index 58533752efab..63dc4b1dfc92 100644 --- a/arch/x86/entry/Makefile +++ b/arch/x86/entry/Makefile @@ -21,12 +21,13 @@ CFLAGS_syscall_64.o += $(call cc-option,-Wno-override-init,) CFLAGS_syscall_32.o += $(call cc-option,-Wno-override-init,) CFLAGS_syscall_x32.o += $(call cc-option,-Wno-override-init,) -obj-y := entry.o entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o +obj-y := entry.o entry_$(BITS).o syscall_$(BITS).o obj-y += common.o obj-y += vdso/ obj-y += vsyscall/ +obj-$(CONFIG_PREEMPTION) += thunk_$(BITS).o obj-$(CONFIG_IA32_EMULATION) += entry_64_compat.o syscall_32.o obj-$(CONFIG_X86_X32_ABI) += syscall_x32.o diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S index 7591bab060f7..ff6e7003da97 100644 --- a/arch/x86/entry/thunk_32.S +++ b/arch/x86/entry/thunk_32.S @@ -29,10 +29,8 @@ SYM_CODE_START_NOALIGN(\name) SYM_CODE_END(\name) .endm -#ifdef CONFIG_PREEMPTION 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) -#endif diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S index 1b5044ad8cd0..14776163fbff 100644 --- a/arch/x86/entry/thunk_64.S +++ b/arch/x86/entry/thunk_64.S @@ -36,14 +36,11 @@ SYM_FUNC_END(\name) _ASM_NOKPROBE(\name) .endm -#ifdef CONFIG_PREEMPTION 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) -#endif -#ifdef CONFIG_PREEMPTION SYM_CODE_START_LOCAL_NOALIGN(__thunk_restore) popq %r11 popq %r10 @@ -58,4 +55,3 @@ SYM_CODE_START_LOCAL_NOALIGN(__thunk_restore) RET _ASM_NOKPROBE(__thunk_restore) SYM_CODE_END(__thunk_restore) -#endif diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile index 77f70b969d14..3113800da63a 100644 --- a/arch/x86/um/Makefile +++ b/arch/x86/um/Makefile @@ -27,7 +27,8 @@ else obj-y += syscalls_64.o vdso/ -subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o ../entry/thunk_64.o +subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o +subarch-$(CONFIG_PREEMPTION) += ../entry/thunk_64.o endif |