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* [PATCH v2 1/9] x86/asm: Mark all top level asm statements as .text
@ 2019-03-30  0:47 Andi Kleen
  2019-03-30  0:47 ` [PATCH v2 2/9] x86/cpu/amd: Ifdef 32bit only assembler for 32bit Andi Kleen
                   ` (8 more replies)
  0 siblings, 9 replies; 20+ messages in thread
From: Andi Kleen @ 2019-03-30  0:47 UTC (permalink / raw)
  To: x86; +Cc: linux-kernel, Andi Kleen

From: Andi Kleen <ak@linux.intel.com>

With gcc toplevel assembler statements that do not mark themselves
as .text may end up in other sections. I had LTO boot crashes because
various assembler statements ended up in the middle of the initcall
section. It's also a latent problem without LTO, although it's
currently not known to cause any real problems.

According to the gcc team it's expected behavior.

Always mark all the top level assembler statements as text
so that they switch to the right section.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/kernel/cpu/amd.c      | 3 ++-
 arch/x86/kernel/kprobes/core.c | 1 +
 arch/x86/lib/error-inject.c    | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 01004bfb1a1b..1bcb489e07e7 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -83,7 +83,8 @@ static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
  */
 
 extern __visible void vide(void);
-__asm__(".globl vide\n"
+__asm__(".text\n"
+	".globl vide\n"
 	".type vide, @function\n"
 	".align 4\n"
 	"vide: ret\n");
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index a034cb808e7e..31ab91c9c4e9 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -715,6 +715,7 @@ NOKPROBE_SYMBOL(kprobe_int3_handler);
  * calls trampoline_handler() runs, which calls the kretprobe's handler.
  */
 asm(
+	".text\n"
 	".global kretprobe_trampoline\n"
 	".type kretprobe_trampoline, @function\n"
 	"kretprobe_trampoline:\n"
diff --git a/arch/x86/lib/error-inject.c b/arch/x86/lib/error-inject.c
index 3cdf06128d13..be5b5fb1598b 100644
--- a/arch/x86/lib/error-inject.c
+++ b/arch/x86/lib/error-inject.c
@@ -6,6 +6,7 @@
 asmlinkage void just_return_func(void);
 
 asm(
+	".text\n"
 	".type just_return_func, @function\n"
 	".globl just_return_func\n"
 	"just_return_func:\n"
-- 
2.20.1


^ permalink raw reply	[flat|nested] 20+ messages in thread

end of thread, other threads:[~2019-05-08 11:20 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-30  0:47 [PATCH v2 1/9] x86/asm: Mark all top level asm statements as .text Andi Kleen
2019-03-30  0:47 ` [PATCH v2 2/9] x86/cpu/amd: Ifdef 32bit only assembler for 32bit Andi Kleen
2019-04-19 15:52   ` [tip:x86/asm] x86/cpu/amd: Exclude 32bit only assembler from 64bit build tip-bot for Andi Kleen
2019-03-30  0:47 ` [PATCH v2 3/9] x86/paravirt: Replace paravirt patches with data Andi Kleen
2019-04-19 21:26   ` Thomas Gleixner
2019-03-30  0:47 ` [PATCH v2 4/9] x86/timer: Don't inline __const_udelay Andi Kleen
2019-04-19 15:55   ` [tip:x86/timers] x86/timer: Don't inline __const_udelay() tip-bot for Andi Kleen
2019-03-30  0:47 ` [PATCH v2 5/9] x86/xen: Mark xen_vcpu_stolen as __visible Andi Kleen
2019-03-30 10:40   ` Juergen Gross
2019-03-30  0:47 ` [PATCH v2 6/9] x86/hyperv: Make hv_vcpu_is_preempted visible Andi Kleen
2019-04-19 15:58   ` [tip:x86/hyperv] x86/hyperv: Make hv_vcpu_is_preempted() visible tip-bot for Andi Kleen
2019-04-19 16:04   ` [tip:x86/platform] " tip-bot for Andi Kleen
2019-03-30  0:47 ` [PATCH v2 7/9] x86/kprobes: Make trampoline_handler global and visible Andi Kleen
2019-04-19 15:58   ` [tip:x86/core] x86/kprobes: Make trampoline_handler() " tip-bot for Andi Kleen
2019-05-08 11:20   ` [tip:x86/urgent] " tip-bot for Andi Kleen
2019-03-30  0:47 ` [PATCH v2 8/9] x86/kvm: Make steal_time visible Andi Kleen
2019-04-19 16:04   ` [tip:x86/platform] " tip-bot for Andi Kleen
2019-03-30  0:47 ` [PATCH v2 9/9] x86/cpu/bugs: Fix __initconst usage in bugs.c Andi Kleen
2019-04-19 15:16   ` [tip:x86/urgent] x86/cpu/bugs: Use __initconst for 'const' init data tip-bot for Andi Kleen
2019-04-19 15:52 ` [tip:x86/asm] x86/asm: Mark all top level asm statements as .text tip-bot for Andi Kleen

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