* [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional
@ 2017-07-28 12:24 Masami Hiramatsu
2017-07-28 12:25 ` [PATCH -tip v6 2/2] [BUGFIX] kprobes/x86: Do not jump-optimize kprobes on irq entry code Masami Hiramatsu
2017-07-28 13:59 ` [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
0 siblings, 2 replies; 3+ messages in thread
From: Masami Hiramatsu @ 2017-07-28 12:24 UTC (permalink / raw
To: Ingo Molnar, Thomas Gleixner
Cc: Francis Deslauriers, mathieu.desnoyers, Ingo Molnar,
H . Peter Anvin, x86, Masami Hiramatsu,
Ananth N Mavinakayanahalli, Anil S Keshavamurthy,
David S . Miller, linux-kernel
Generate irqentry and softirqentry text sections without
any configs. This will add above extra sections, but
no performace impact.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Ingo Molnar <mingo@kernel.org>
---
arch/arm/include/asm/traps.h | 7 -------
arch/arm64/include/asm/traps.h | 7 -------
arch/x86/entry/entry_64.S | 9 ++-------
include/asm-generic/sections.h | 4 ++++
include/asm-generic/vmlinux.lds.h | 8 --------
include/linux/interrupt.h | 14 +-------------
6 files changed, 7 insertions(+), 42 deletions(-)
diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
index f555bb3664dc..683d9230984a 100644
--- a/arch/arm/include/asm/traps.h
+++ b/arch/arm/include/asm/traps.h
@@ -18,7 +18,6 @@ struct undef_hook {
void register_undef_hook(struct undef_hook *hook);
void unregister_undef_hook(struct undef_hook *hook);
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static inline int __in_irqentry_text(unsigned long ptr)
{
extern char __irqentry_text_start[];
@@ -27,12 +26,6 @@ static inline int __in_irqentry_text(unsigned long ptr)
return ptr >= (unsigned long)&__irqentry_text_start &&
ptr < (unsigned long)&__irqentry_text_end;
}
-#else
-static inline int __in_irqentry_text(unsigned long ptr)
-{
- return 0;
-}
-#endif
static inline int in_exception_text(unsigned long ptr)
{
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 02e9035b0685..47a9066f7c86 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -37,18 +37,11 @@ void unregister_undef_hook(struct undef_hook *hook);
void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr);
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static inline int __in_irqentry_text(unsigned long ptr)
{
return ptr >= (unsigned long)&__irqentry_text_start &&
ptr < (unsigned long)&__irqentry_text_end;
}
-#else
-static inline int __in_irqentry_text(unsigned long ptr)
-{
- return 0;
-}
-#endif
static inline int in_exception_text(unsigned long ptr)
{
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index aa58155187c5..5e41396efbbf 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -766,13 +766,8 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
#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
+#define PUSH_SECTION_IRQENTRY .pushsection .irqentry.text, "ax"
+#define POP_SECTION_IRQENTRY .popsection
.macro apicinterrupt num sym do_sym
PUSH_SECTION_IRQENTRY
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 532372c6cf15..e5da44eddd2f 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -27,6 +27,8 @@
* __kprobes_text_start, __kprobes_text_end
* __entry_text_start, __entry_text_end
* __ctors_start, __ctors_end
+ * __irqentry_text_start, __irqentry_text_end
+ * __softirqentry_text_start, __softirqentry_text_end
*/
extern char _text[], _stext[], _etext[];
extern char _data[], _sdata[], _edata[];
@@ -39,6 +41,8 @@ extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
extern char __kprobes_text_start[], __kprobes_text_end[];
extern char __entry_text_start[], __entry_text_end[];
extern char __start_rodata[], __end_rodata[];
+extern char __irqentry_text_start[], __irqentry_text_end[];
+extern char __softirqentry_text_start[], __softirqentry_text_end[];
/* Start and end of .ctors section - used for constructor calls. */
extern char __ctors_start[], __ctors_end[];
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index fffc9bdae025..438b014c192f 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -483,25 +483,17 @@
*(.entry.text) \
VMLINUX_SYMBOL(__entry_text_end) = .;
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
#define IRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__irqentry_text_start) = .; \
*(.irqentry.text) \
VMLINUX_SYMBOL(__irqentry_text_end) = .;
-#else
-#define IRQENTRY_TEXT
-#endif
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
#define SOFTIRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__softirqentry_text_start) = .; \
*(.softirqentry.text) \
VMLINUX_SYMBOL(__softirqentry_text_end) = .;
-#else
-#define SOFTIRQENTRY_TEXT
-#endif
/* Section used for early init (in .S files) */
#define HEAD_TEXT *(.head.text)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index a2fddddb0d60..59ba11661b6e 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -18,6 +18,7 @@
#include <linux/atomic.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
+#include <asm/sections.h>
/*
* These correspond to the IORESOURCE_IRQ_* defines in
@@ -726,7 +727,6 @@ extern int early_irq_init(void);
extern int arch_probe_nr_irqs(void);
extern int arch_early_irq_init(void);
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
/*
* We want to know which function is an entrypoint of a hardirq or a softirq.
*/
@@ -734,16 +734,4 @@ extern int arch_early_irq_init(void);
#define __softirq_entry \
__attribute__((__section__(".softirqentry.text")))
-/* Limits of hardirq entrypoints */
-extern char __irqentry_text_start[];
-extern char __irqentry_text_end[];
-/* Limits of softirq entrypoints */
-extern char __softirqentry_text_start[];
-extern char __softirqentry_text_end[];
-
-#else
-#define __irq_entry
-#define __softirq_entry
-#endif
-
#endif
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH -tip v6 2/2] [BUGFIX] kprobes/x86: Do not jump-optimize kprobes on irq entry code
2017-07-28 12:24 [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
@ 2017-07-28 12:25 ` Masami Hiramatsu
2017-07-28 13:59 ` [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
1 sibling, 0 replies; 3+ messages in thread
From: Masami Hiramatsu @ 2017-07-28 12:25 UTC (permalink / raw
To: Ingo Molnar, Thomas Gleixner
Cc: Francis Deslauriers, mathieu.desnoyers, Ingo Molnar,
H . Peter Anvin, x86, Masami Hiramatsu,
Ananth N Mavinakayanahalli, Anil S Keshavamurthy,
David S . Miller, linux-kernel
Since the kernel segment registers are not prepared at the
entry of irq-entry code, if a kprobe on such code is
jump-optimized, accessing per-cpu variables may cause
kernel panic.
However, if the kprobe is not optimized, it kicks int3
exception and set segment registers correctly.
This checks probe-address and if it is in irq-entry code,
it prohibits optimizing such kprobes. This means we can
continuously probing such interrupt handlers by kprobes
but it is not optimized anymore.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com>
---
Changes in v6:
- Update for unconditional irqentry.
---
arch/x86/kernel/kprobes/opt.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 69ea0bc1cfa3..4f98aad38237 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -39,6 +39,7 @@
#include <asm/insn.h>
#include <asm/debugreg.h>
#include <asm/set_memory.h>
+#include <asm/sections.h>
#include "common.h"
@@ -251,10 +252,12 @@ static int can_optimize(unsigned long paddr)
/*
* Do not optimize in the entry code due to the unstable
- * stack handling.
+ * stack handling and registers setup.
*/
- if ((paddr >= (unsigned long)__entry_text_start) &&
- (paddr < (unsigned long)__entry_text_end))
+ if (((paddr >= (unsigned long)__entry_text_start) &&
+ (paddr < (unsigned long)__entry_text_end)) ||
+ ((paddr >= (unsigned long)__irqentry_text_start) &&
+ (paddr < (unsigned long)__irqentry_text_end)))
return 0;
/* Check there is enough space for a relative jump. */
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional
2017-07-28 12:24 [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
2017-07-28 12:25 ` [PATCH -tip v6 2/2] [BUGFIX] kprobes/x86: Do not jump-optimize kprobes on irq entry code Masami Hiramatsu
@ 2017-07-28 13:59 ` Masami Hiramatsu
1 sibling, 0 replies; 3+ messages in thread
From: Masami Hiramatsu @ 2017-07-28 13:59 UTC (permalink / raw
To: Masami Hiramatsu
Cc: Ingo Molnar, Thomas Gleixner, Francis Deslauriers,
mathieu.desnoyers, Ingo Molnar, H . Peter Anvin, x86,
Ananth N Mavinakayanahalli, Anil S Keshavamurthy,
David S . Miller, linux-kernel
On Fri, 28 Jul 2017 21:24:54 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Generate irqentry and softirqentry text sections without
> any configs. This will add above extra sections, but
> no performace impact.
>
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> Suggested-by: Ingo Molnar <mingo@kernel.org>
> ---
> arch/arm/include/asm/traps.h | 7 -------
> arch/arm64/include/asm/traps.h | 7 -------
> arch/x86/entry/entry_64.S | 9 ++-------
> include/asm-generic/sections.h | 4 ++++
> include/asm-generic/vmlinux.lds.h | 8 --------
> include/linux/interrupt.h | 14 +-------------
> 6 files changed, 7 insertions(+), 42 deletions(-)
Oops, I forgot to fix x86 unwind code.
I'll update this to fix in_entry_code() unconditional.
Thanks,
>
> diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
> index f555bb3664dc..683d9230984a 100644
> --- a/arch/arm/include/asm/traps.h
> +++ b/arch/arm/include/asm/traps.h
> @@ -18,7 +18,6 @@ struct undef_hook {
> void register_undef_hook(struct undef_hook *hook);
> void unregister_undef_hook(struct undef_hook *hook);
>
> -#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> static inline int __in_irqentry_text(unsigned long ptr)
> {
> extern char __irqentry_text_start[];
> @@ -27,12 +26,6 @@ static inline int __in_irqentry_text(unsigned long ptr)
> return ptr >= (unsigned long)&__irqentry_text_start &&
> ptr < (unsigned long)&__irqentry_text_end;
> }
> -#else
> -static inline int __in_irqentry_text(unsigned long ptr)
> -{
> - return 0;
> -}
> -#endif
>
> static inline int in_exception_text(unsigned long ptr)
> {
> diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
> index 02e9035b0685..47a9066f7c86 100644
> --- a/arch/arm64/include/asm/traps.h
> +++ b/arch/arm64/include/asm/traps.h
> @@ -37,18 +37,11 @@ void unregister_undef_hook(struct undef_hook *hook);
>
> void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr);
>
> -#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> static inline int __in_irqentry_text(unsigned long ptr)
> {
> return ptr >= (unsigned long)&__irqentry_text_start &&
> ptr < (unsigned long)&__irqentry_text_end;
> }
> -#else
> -static inline int __in_irqentry_text(unsigned long ptr)
> -{
> - return 0;
> -}
> -#endif
>
> static inline int in_exception_text(unsigned long ptr)
> {
> diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> index aa58155187c5..5e41396efbbf 100644
> --- a/arch/x86/entry/entry_64.S
> +++ b/arch/x86/entry/entry_64.S
> @@ -766,13 +766,8 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
> #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
> +#define PUSH_SECTION_IRQENTRY .pushsection .irqentry.text, "ax"
> +#define POP_SECTION_IRQENTRY .popsection
>
> .macro apicinterrupt num sym do_sym
> PUSH_SECTION_IRQENTRY
> diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
> index 532372c6cf15..e5da44eddd2f 100644
> --- a/include/asm-generic/sections.h
> +++ b/include/asm-generic/sections.h
> @@ -27,6 +27,8 @@
> * __kprobes_text_start, __kprobes_text_end
> * __entry_text_start, __entry_text_end
> * __ctors_start, __ctors_end
> + * __irqentry_text_start, __irqentry_text_end
> + * __softirqentry_text_start, __softirqentry_text_end
> */
> extern char _text[], _stext[], _etext[];
> extern char _data[], _sdata[], _edata[];
> @@ -39,6 +41,8 @@ extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
> extern char __kprobes_text_start[], __kprobes_text_end[];
> extern char __entry_text_start[], __entry_text_end[];
> extern char __start_rodata[], __end_rodata[];
> +extern char __irqentry_text_start[], __irqentry_text_end[];
> +extern char __softirqentry_text_start[], __softirqentry_text_end[];
>
> /* Start and end of .ctors section - used for constructor calls. */
> extern char __ctors_start[], __ctors_end[];
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index fffc9bdae025..438b014c192f 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -483,25 +483,17 @@
> *(.entry.text) \
> VMLINUX_SYMBOL(__entry_text_end) = .;
>
> -#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> #define IRQENTRY_TEXT \
> ALIGN_FUNCTION(); \
> VMLINUX_SYMBOL(__irqentry_text_start) = .; \
> *(.irqentry.text) \
> VMLINUX_SYMBOL(__irqentry_text_end) = .;
> -#else
> -#define IRQENTRY_TEXT
> -#endif
>
> -#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> #define SOFTIRQENTRY_TEXT \
> ALIGN_FUNCTION(); \
> VMLINUX_SYMBOL(__softirqentry_text_start) = .; \
> *(.softirqentry.text) \
> VMLINUX_SYMBOL(__softirqentry_text_end) = .;
> -#else
> -#define SOFTIRQENTRY_TEXT
> -#endif
>
> /* Section used for early init (in .S files) */
> #define HEAD_TEXT *(.head.text)
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index a2fddddb0d60..59ba11661b6e 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -18,6 +18,7 @@
> #include <linux/atomic.h>
> #include <asm/ptrace.h>
> #include <asm/irq.h>
> +#include <asm/sections.h>
>
> /*
> * These correspond to the IORESOURCE_IRQ_* defines in
> @@ -726,7 +727,6 @@ extern int early_irq_init(void);
> extern int arch_probe_nr_irqs(void);
> extern int arch_early_irq_init(void);
>
> -#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> /*
> * We want to know which function is an entrypoint of a hardirq or a softirq.
> */
> @@ -734,16 +734,4 @@ extern int arch_early_irq_init(void);
> #define __softirq_entry \
> __attribute__((__section__(".softirqentry.text")))
>
> -/* Limits of hardirq entrypoints */
> -extern char __irqentry_text_start[];
> -extern char __irqentry_text_end[];
> -/* Limits of softirq entrypoints */
> -extern char __softirqentry_text_start[];
> -extern char __softirqentry_text_end[];
> -
> -#else
> -#define __irq_entry
> -#define __softirq_entry
> -#endif
> -
> #endif
>
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-07-28 13:59 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2017-07-28 12:24 [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
2017-07-28 12:25 ` [PATCH -tip v6 2/2] [BUGFIX] kprobes/x86: Do not jump-optimize kprobes on irq entry code Masami Hiramatsu
2017-07-28 13:59 ` [PATCH -tip v6 1/2] irq: Make irqentry text section unconditional Masami Hiramatsu
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