RE: [PATCH v3] Introduce page fault tracepoint
Thank you for reviewing. > > http://marc.info/?l=linux-mm=136807959830182=2 > > http://marc.info/?l=linux-mm=136807959130175=2 > > > > For permanence, please use links of the form: > > http://lkml.kernel.org/r/message-id > > (Yes, they currently point to marc.info, but can be redirected to point > to any archive.) I will fix it. > This is needlessly confusing, which is apart of why reviewing this patch > took a lot more time than it should. > > Please break this patch into two: one which sets up the tracing IDT and > one to create the #PF tracepoint. The assumption is, I am assuming, > there will be more. OK. I will divide the patch into two or more to make the review smooth. Seiji > > -hpa
RE: [PATCH v3] Introduce page fault tracepoint
Thank you for reviewing. http://marc.info/?l=linux-mmm=136807959830182w=2 http://marc.info/?l=linux-mmm=136807959130175w=2 For permanence, please use links of the form: http://lkml.kernel.org/r/message-id (Yes, they currently point to marc.info, but can be redirected to point to any archive.) I will fix it. This is needlessly confusing, which is apart of why reviewing this patch took a lot more time than it should. Please break this patch into two: one which sets up the tracing IDT and one to create the #PF tracepoint. The assumption is, I am assuming, there will be more. OK. I will divide the patch into two or more to make the review smooth. Seiji -hpa
Re: [PATCH v3] Introduce page fault tracepoint
On 09/09/2013 02:55 PM, Seiji Aguchi wrote: > Change from v2 > - Print entry->ip instead of entry->regs->ip to avoid kernel crash. > - Use %pf instead of 0x%lx to print address and ip. > > This patch introduces page fault tracepoints to x86 architecture > by switching IDT. > > [Use case of page fault events] > > Two events, for user and kernel spaces, are introduced at the beginning of > page fault handler. > > - User space event > There is a request of page fault event for user space as below. > > http://marc.info/?l=linux-mm=136807959830182=2 > http://marc.info/?l=linux-mm=136807959130175=2 > For permanence, please use links of the form: http://lkml.kernel.org/r/message-id (Yes, they currently point to marc.info, but can be redirected to point to any archive.) > - Kernel space event: > Overhead in kernel space is measurable by enabling it. > > [Creating IDT] > > A way to create IDT is as below. > > - Introduce set_intr_gate_raw() to register just non-trace handler to IDT. >This is used at boot time which tracing is disabled. > - Make set_intr_gate() macro so that it can register trace handler to >trace IDT and non-trace handler to normal IDT. > This is needlessly confusing, which is apart of why reviewing this patch took a lot more time than it should. Please break this patch into two: one which sets up the tracing IDT and one to create the #PF tracepoint. The assumption is, I am assuming, there will be more. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3] Introduce page fault tracepoint
On 09/09/2013 02:55 PM, Seiji Aguchi wrote: Change from v2 - Print entry-ip instead of entry-regs-ip to avoid kernel crash. - Use %pf instead of 0x%lx to print address and ip. This patch introduces page fault tracepoints to x86 architecture by switching IDT. [Use case of page fault events] Two events, for user and kernel spaces, are introduced at the beginning of page fault handler. - User space event There is a request of page fault event for user space as below. http://marc.info/?l=linux-mmm=136807959830182w=2 http://marc.info/?l=linux-mmm=136807959130175w=2 For permanence, please use links of the form: http://lkml.kernel.org/r/message-id (Yes, they currently point to marc.info, but can be redirected to point to any archive.) - Kernel space event: Overhead in kernel space is measurable by enabling it. [Creating IDT] A way to create IDT is as below. - Introduce set_intr_gate_raw() to register just non-trace handler to IDT. This is used at boot time which tracing is disabled. - Make set_intr_gate() macro so that it can register trace handler to trace IDT and non-trace handler to normal IDT. This is needlessly confusing, which is apart of why reviewing this patch took a lot more time than it should. Please break this patch into two: one which sets up the tracing IDT and one to create the #PF tracepoint. The assumption is, I am assuming, there will be more. -hpa -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: [PATCH v3] Introduce page fault tracepoint
Peter,
Any comment?
Seiji
> -Original Message-
> From: linux-kernel-ow...@vger.kernel.org
> [mailto:linux-kernel-ow...@vger.kernel.org] On Behalf Of Seiji Aguchi
> Sent: Monday, September 09, 2013 5:56 PM
> To: linux-kernel@vger.kernel.org; x...@kernel.org
> Cc: h...@zytor.com; rost...@goodmis.org; mi...@elte.hu; b...@alien8.de;
> t...@linutronix.de; fdesl...@gmail.com;
> raphael.beamo...@gmail.com; dle-deve...@lists.sourceforge.net; Tomoki Sekiyama
> Subject: [PATCH v3] Introduce page fault tracepoint
>
> Change from v2
> - Print entry->ip instead of entry->regs->ip to avoid kernel crash.
> - Use %pf instead of 0x%lx to print address and ip.
>
> This patch introduces page fault tracepoints to x86 architecture
> by switching IDT.
>
> [Use case of page fault events]
>
> Two events, for user and kernel spaces, are introduced at the beginning of
> page fault handler.
>
> - User space event
> There is a request of page fault event for user space as below.
>
> http://marc.info/?l=linux-mm=136807959830182=2
> http://marc.info/?l=linux-mm=136807959130175=2
>
> - Kernel space event:
> Overhead in kernel space is measurable by enabling it.
>
> [Creating IDT]
>
> A way to create IDT is as below.
>
> - Introduce set_intr_gate_raw() to register just non-trace handler to IDT.
>This is used at boot time which tracing is disabled.
> - Make set_intr_gate() macro so that it can register trace handler to
>trace IDT and non-trace handler to normal IDT.
>
> Signed-off-by: Seiji Aguchi
> ---
> arch/x86/include/asm/desc.h | 33 +
> arch/x86/include/asm/hw_irq.h | 14 -
> arch/x86/include/asm/trace/exceptions.h | 52
> +
> arch/x86/include/asm/traps.h| 22 ++
> arch/x86/kernel/entry_32.S | 10 +++
> arch/x86/kernel/entry_64.S | 13 -
> arch/x86/kernel/head64.c| 2 +-
> arch/x86/kernel/irqinit.c | 2 +-
> arch/x86/kernel/kvm.c | 2 +-
> arch/x86/kernel/traps.c | 28 +-
> arch/x86/mm/Makefile| 2 ++
> arch/x86/mm/fault.c | 22 ++
> 12 files changed, 178 insertions(+), 24 deletions(-)
> create mode 100644 arch/x86/include/asm/trace/exceptions.h
>
> diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
> index b90e5df..c04302b 100644
> --- a/arch/x86/include/asm/desc.h
> +++ b/arch/x86/include/asm/desc.h
> @@ -327,10 +327,28 @@ static inline void write_trace_idt_entry(int entry,
> const gate_desc *gate)
> {
> write_idt_entry(trace_idt_table, entry, gate);
> }
> +
> +static inline void _trace_set_gate(int gate, unsigned type, void *addr,
> +unsigned dpl, unsigned ist, unsigned seg)
> +{
> + gate_desc s;
> +
> + pack_gate(, type, (unsigned long)addr, dpl, ist, seg);
> + /*
> + * does not need to be atomic because it is only done once at
> + * setup time
> + */
> + write_trace_idt_entry(gate, );
> +}
> #else
> static inline void write_trace_idt_entry(int entry, const gate_desc *gate)
> {
> }
> +
> +static inline void _trace_set_gate(int gate, unsigned type, void *addr,
> +unsigned dpl, unsigned ist, unsigned seg)
> +{
> +}
> #endif
>
> static inline void _set_gate(int gate, unsigned type, void *addr,
> @@ -353,12 +371,20 @@ static inline void _set_gate(int gate, unsigned type,
> void *addr,
> * Pentium F0 0F bugfix can have resulted in the mapped
> * IDT being write-protected.
> */
> -static inline void set_intr_gate(unsigned int n, void *addr)
> +static inline void set_intr_gate_raw(unsigned int n, void *addr)
> {
> BUG_ON((unsigned)n > 0xFF);
> _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
> }
>
> +#define set_intr_gate(n, addr)
> \
> + do {\
> + BUG_ON((unsigned)n > 0xFF); \
> + _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS); \
> + _trace_set_gate(n, GATE_INTERRUPT, trace_##addr, 0, 0, \
> + __KERNEL_CS); \
> + } while (0)
> +
> extern int first_system_vector;
> /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
> extern unsigned long used_vectors[];
> @@ -395,10 +421,7 @@ static inline void trace_set_intr_gate(unsigned int
> gate, void *addr)
> #define __trace_alloc_intr_gate(n, addr)
> #endif
>
> -static inline void __alloc_intr_gate(unsigned int n, void *addr)
> -{
> - set_intr_gate(n, addr);
> -}
> +#define __alloc_intr_gate(n, addr) set_intr_gate(n, addr)
>
> #define alloc_intr_gate(n, addr) \
> do {
RE: [PATCH v3] Introduce page fault tracepoint
Peter,
Any comment?
Seiji
-Original Message-
From: linux-kernel-ow...@vger.kernel.org
[mailto:linux-kernel-ow...@vger.kernel.org] On Behalf Of Seiji Aguchi
Sent: Monday, September 09, 2013 5:56 PM
To: linux-kernel@vger.kernel.org; x...@kernel.org
Cc: h...@zytor.com; rost...@goodmis.org; mi...@elte.hu; b...@alien8.de;
t...@linutronix.de; fdesl...@gmail.com;
raphael.beamo...@gmail.com; dle-deve...@lists.sourceforge.net; Tomoki Sekiyama
Subject: [PATCH v3] Introduce page fault tracepoint
Change from v2
- Print entry-ip instead of entry-regs-ip to avoid kernel crash.
- Use %pf instead of 0x%lx to print address and ip.
This patch introduces page fault tracepoints to x86 architecture
by switching IDT.
[Use case of page fault events]
Two events, for user and kernel spaces, are introduced at the beginning of
page fault handler.
- User space event
There is a request of page fault event for user space as below.
http://marc.info/?l=linux-mmm=136807959830182w=2
http://marc.info/?l=linux-mmm=136807959130175w=2
- Kernel space event:
Overhead in kernel space is measurable by enabling it.
[Creating IDT]
A way to create IDT is as below.
- Introduce set_intr_gate_raw() to register just non-trace handler to IDT.
This is used at boot time which tracing is disabled.
- Make set_intr_gate() macro so that it can register trace handler to
trace IDT and non-trace handler to normal IDT.
Signed-off-by: Seiji Aguchi seiji.agu...@hds.com
---
arch/x86/include/asm/desc.h | 33 +
arch/x86/include/asm/hw_irq.h | 14 -
arch/x86/include/asm/trace/exceptions.h | 52
+
arch/x86/include/asm/traps.h| 22 ++
arch/x86/kernel/entry_32.S | 10 +++
arch/x86/kernel/entry_64.S | 13 -
arch/x86/kernel/head64.c| 2 +-
arch/x86/kernel/irqinit.c | 2 +-
arch/x86/kernel/kvm.c | 2 +-
arch/x86/kernel/traps.c | 28 +-
arch/x86/mm/Makefile| 2 ++
arch/x86/mm/fault.c | 22 ++
12 files changed, 178 insertions(+), 24 deletions(-)
create mode 100644 arch/x86/include/asm/trace/exceptions.h
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index b90e5df..c04302b 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -327,10 +327,28 @@ static inline void write_trace_idt_entry(int entry,
const gate_desc *gate)
{
write_idt_entry(trace_idt_table, entry, gate);
}
+
+static inline void _trace_set_gate(int gate, unsigned type, void *addr,
+unsigned dpl, unsigned ist, unsigned seg)
+{
+ gate_desc s;
+
+ pack_gate(s, type, (unsigned long)addr, dpl, ist, seg);
+ /*
+ * does not need to be atomic because it is only done once at
+ * setup time
+ */
+ write_trace_idt_entry(gate, s);
+}
#else
static inline void write_trace_idt_entry(int entry, const gate_desc *gate)
{
}
+
+static inline void _trace_set_gate(int gate, unsigned type, void *addr,
+unsigned dpl, unsigned ist, unsigned seg)
+{
+}
#endif
static inline void _set_gate(int gate, unsigned type, void *addr,
@@ -353,12 +371,20 @@ static inline void _set_gate(int gate, unsigned type,
void *addr,
* Pentium F0 0F bugfix can have resulted in the mapped
* IDT being write-protected.
*/
-static inline void set_intr_gate(unsigned int n, void *addr)
+static inline void set_intr_gate_raw(unsigned int n, void *addr)
{
BUG_ON((unsigned)n 0xFF);
_set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
}
+#define set_intr_gate(n, addr)
\
+ do {\
+ BUG_ON((unsigned)n 0xFF); \
+ _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS); \
+ _trace_set_gate(n, GATE_INTERRUPT, trace_##addr, 0, 0, \
+ __KERNEL_CS); \
+ } while (0)
+
extern int first_system_vector;
/* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
extern unsigned long used_vectors[];
@@ -395,10 +421,7 @@ static inline void trace_set_intr_gate(unsigned int
gate, void *addr)
#define __trace_alloc_intr_gate(n, addr)
#endif
-static inline void __alloc_intr_gate(unsigned int n, void *addr)
-{
- set_intr_gate(n, addr);
-}
+#define __alloc_intr_gate(n, addr) set_intr_gate(n, addr)
#define alloc_intr_gate(n, addr) \
do {\
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
