[PATCH v2] x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

[PATCH v2] x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

[Alexander Potapenko]

When building with CONFIG_FUNCTION_GRAPH_TRACER or CONFIG_KASAN, put the
APIC interrupt handlers into the .irqentry.text section. This is needed
because both KASAN and function graph tracer use __irqentry_text_start and
__irqentry_text_end to determine whether a function is an IRQ entry point.

Dmitry Vyukov has reported unexpected KASAN stackdepot growth
(https://github.com/google/kasan/issues/36), which had been caused by
the APIC handlers not being present in .irqentry.text.

Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
---
v2: - fixed kbuild warning (incorrect #if directive)
---
 arch/x86/entry/entry_64.S | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9ee0da1..2ef4f0b 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -601,9 +601,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
 .endm
 #endif
 
+/* Make sure APIC interrupt handlers end up in the irqentry section. */
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#define PUSH_SECTION_IRQENTRY	.pushsection .irqentry.text, "ax"
+#define POP_SECTION_IRQENTRY	.popsection
+#else
+#define PUSH_SECTION_IRQENTRY
+#define POP_SECTION_IRQENTRY
+#endif
+
 .macro apicinterrupt num sym do_sym
+PUSH_SECTION_IRQENTRY
 apicinterrupt3 \num \sym \do_sym
 trace_apicinterrupt \num \sym
+POP_SECTION_IRQENTRY
 .endm
 
 #ifdef CONFIG_SMP
-- 
2.8.0.rc3.226.g39d4020

Re: [PATCH v2] x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

[Alexander Potapenko]

On Fri, Jul 15, 2016 at 11:42 AM, Alexander Potapenko <glider@google.com> wrote:
> When building with CONFIG_FUNCTION_GRAPH_TRACER or CONFIG_KASAN, put the
> APIC interrupt handlers into the .irqentry.text section. This is needed
> because both KASAN and function graph tracer use __irqentry_text_start and
> __irqentry_text_end to determine whether a function is an IRQ entry point.
>
> Dmitry Vyukov has reported unexpected KASAN stackdepot growth
> (https://github.com/google/kasan/issues/36), which had been caused by
> the APIC handlers not being present in .irqentry.text.
>
> Signed-off-by: Alexander Potapenko <glider@google.com>
> Reported-by: Dmitry Vyukov <dvyukov@google.com>
> ---
> v2: - fixed kbuild warning (incorrect #if directive)
> ---
>  arch/x86/entry/entry_64.S | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> index 9ee0da1..2ef4f0b 100644
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -601,9 +601,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
>  .endm
>  #endif
>
> +/* Make sure APIC interrupt handlers end up in the irqentry section. */
> +#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> +#define PUSH_SECTION_IRQENTRY  .pushsection .irqentry.text, "ax"
> +#define POP_SECTION_IRQENTRY   .popsection
> +#else
> +#define PUSH_SECTION_IRQENTRY
> +#define POP_SECTION_IRQENTRY
> +#endif
> +
>  .macro apicinterrupt num sym do_sym
> +PUSH_SECTION_IRQENTRY
>  apicinterrupt3 \num \sym \do_sym
>  trace_apicinterrupt \num \sym
> +POP_SECTION_IRQENTRY
>  .endm
>
>  #ifdef CONFIG_SMP
> --
> 2.8.0.rc3.226.g39d4020
>
A friendly ping.


-- 
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg

[tip:x86/mm] x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

[tip-bot for Alexander Potapenko]

Commit-ID:  469f00231278da68062a809306df0bac95a27507
Gitweb:     http://git.kernel.org/tip/469f00231278da68062a809306df0bac95a27507
Author:     Alexander Potapenko <glider@google.com>
AuthorDate: Fri, 15 Jul 2016 11:42:43 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 10 Aug 2016 14:19:33 +0200

x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text

Dmitry Vyukov has reported unexpected KASAN stackdepot growth:

  https://github.com/google/kasan/issues/36

... which is caused by the APIC handlers not being present in .irqentry.text:

When building with CONFIG_FUNCTION_GRAPH_TRACER=y or CONFIG_KASAN=y, put the
APIC interrupt handlers into the .irqentry.text section. This is needed
because both KASAN and function graph tracer use __irqentry_text_start and
__irqentry_text_end to determine whether a function is an IRQ entry point.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: aryabinin@virtuozzo.com
Cc: kasan-dev@googlegroups.com
Cc: kcc@google.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1468575763-144889-1-git-send-email-glider@google.com
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/entry/entry_64.S | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index b846875..9f85827 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -601,9 +601,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
 .endm
 #endif
 
+/* Make sure APIC interrupt handlers end up in the irqentry section: */
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+# define PUSH_SECTION_IRQENTRY	.pushsection .irqentry.text, "ax"
+# define POP_SECTION_IRQENTRY	.popsection
+#else
+# define PUSH_SECTION_IRQENTRY
+# define POP_SECTION_IRQENTRY
+#endif
+
 .macro apicinterrupt num sym do_sym
+PUSH_SECTION_IRQENTRY
 apicinterrupt3 \num \sym \do_sym
 trace_apicinterrupt \num \sym
+POP_SECTION_IRQENTRY
 .endm
 
 #ifdef CONFIG_SMP