All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v2] arm64: kgdb: handle read-only text / modules
@ 2016-09-21  7:19 ` AKASHI Takahiro
  0 siblings, 0 replies; 6+ messages in thread
From: AKASHI Takahiro @ 2016-09-21  7:19 UTC (permalink / raw)
  To: catalin.marinas, will.deacon, jason.wessel
  Cc: mark.rutland, linux-arm-kernel, kgdb-bugreport, stable, AKASHI Takahiro

Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
by using aarch64_insn_write() instead of probe_kernel_write().
See how this works:
    commit 2f896d586610 ("arm64: use fixmap for text patching")

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
Cc: <stable@vger.kernel.org> # 4.0-
---
 arch/arm64/include/asm/debug-monitors.h |  2 --
 arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 4b6b3f7..b71420a 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -61,8 +61,6 @@
 
 #define AARCH64_BREAK_KGDB_DYN_DBG	\
 	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
-#define KGDB_DYN_BRK_INS_BYTE(x)	\
-	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
 
 #define CACHE_FLUSH_IS_SAFE		1
 
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index 6732a27..b06a7a2 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -19,6 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/bug.h>
 #include <linux/cpumask.h>
 #include <linux/irq.h>
 #include <linux/irq_work.h>
@@ -26,6 +27,8 @@
 #include <linux/kgdb.h>
 #include <linux/kprobes.h>
 #include <linux/percpu.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
 #include <asm/ptrace.h>
 #include <asm/traps.h>
 
@@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
 	unregister_die_notifier(&kgdb_notifier);
 }
 
-/*
- * ARM instructions are always in LE.
- * Break instruction is encoded in LE format
- */
-struct kgdb_arch arch_kgdb_ops = {
-	.gdb_bpt_instr = {
-		KGDB_DYN_BRK_INS_BYTE(0),
-		KGDB_DYN_BRK_INS_BYTE(1),
-		KGDB_DYN_BRK_INS_BYTE(2),
-		KGDB_DYN_BRK_INS_BYTE(3),
-	}
-};
+struct kgdb_arch arch_kgdb_ops;
+
+int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
+{
+	int err;
+
+	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
+
+	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
+	if (err)
+		return err;
+
+	return aarch64_insn_write((void *)bpt->bpt_addr,
+			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
+}
+
+int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
+{
+	return aarch64_insn_write((void *)bpt->bpt_addr,
+			*(u32 *)bpt->saved_instr);
+}
-- 
2.10.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v2] arm64: kgdb: handle read-only text / modules
@ 2016-09-21  7:19 ` AKASHI Takahiro
  0 siblings, 0 replies; 6+ messages in thread
From: AKASHI Takahiro @ 2016-09-21  7:19 UTC (permalink / raw)
  To: linux-arm-kernel

Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
by using aarch64_insn_write() instead of probe_kernel_write().
See how this works:
    commit 2f896d586610 ("arm64: use fixmap for text patching")

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
Cc: <stable@vger.kernel.org> # 4.0-
---
 arch/arm64/include/asm/debug-monitors.h |  2 --
 arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 4b6b3f7..b71420a 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -61,8 +61,6 @@
 
 #define AARCH64_BREAK_KGDB_DYN_DBG	\
 	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
-#define KGDB_DYN_BRK_INS_BYTE(x)	\
-	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
 
 #define CACHE_FLUSH_IS_SAFE		1
 
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index 6732a27..b06a7a2 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -19,6 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/bug.h>
 #include <linux/cpumask.h>
 #include <linux/irq.h>
 #include <linux/irq_work.h>
@@ -26,6 +27,8 @@
 #include <linux/kgdb.h>
 #include <linux/kprobes.h>
 #include <linux/percpu.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
 #include <asm/ptrace.h>
 #include <asm/traps.h>
 
@@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
 	unregister_die_notifier(&kgdb_notifier);
 }
 
-/*
- * ARM instructions are always in LE.
- * Break instruction is encoded in LE format
- */
-struct kgdb_arch arch_kgdb_ops = {
-	.gdb_bpt_instr = {
-		KGDB_DYN_BRK_INS_BYTE(0),
-		KGDB_DYN_BRK_INS_BYTE(1),
-		KGDB_DYN_BRK_INS_BYTE(2),
-		KGDB_DYN_BRK_INS_BYTE(3),
-	}
-};
+struct kgdb_arch arch_kgdb_ops;
+
+int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
+{
+	int err;
+
+	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
+
+	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
+	if (err)
+		return err;
+
+	return aarch64_insn_write((void *)bpt->bpt_addr,
+			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
+}
+
+int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
+{
+	return aarch64_insn_write((void *)bpt->bpt_addr,
+			*(u32 *)bpt->saved_instr);
+}
-- 
2.10.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] arm64: kgdb: handle read-only text / modules
  2016-09-21  7:19 ` AKASHI Takahiro
@ 2016-09-21  8:57   ` Mark Rutland
  -1 siblings, 0 replies; 6+ messages in thread
From: Mark Rutland @ 2016-09-21  8:57 UTC (permalink / raw)
  To: AKASHI Takahiro
  Cc: catalin.marinas, will.deacon, jason.wessel, linux-arm-kernel,
	kgdb-bugreport, stable

On Wed, Sep 21, 2016 at 04:19:55PM +0900, AKASHI Takahiro wrote:
> Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
> by using aarch64_insn_write() instead of probe_kernel_write().
> See how this works:
>     commit 2f896d586610 ("arm64: use fixmap for text patching")
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jason Wessel <jason.wessel@windriver.com>
> Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
> Cc: <stable@vger.kernel.org> # 4.0-

For v3.18-v3.19, we also need commit f6242cac10427c54 ("arm64: Fix text
patching logic when using fixmap"), so as to not break the
!CONFIG_DEBUG_SET_MODULE_RONX case.

With that:

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.

> ---
>  arch/arm64/include/asm/debug-monitors.h |  2 --
>  arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
>  2 files changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
> index 4b6b3f7..b71420a 100644
> --- a/arch/arm64/include/asm/debug-monitors.h
> +++ b/arch/arm64/include/asm/debug-monitors.h
> @@ -61,8 +61,6 @@
>  
>  #define AARCH64_BREAK_KGDB_DYN_DBG	\
>  	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
> -#define KGDB_DYN_BRK_INS_BYTE(x)	\
> -	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
>  
>  #define CACHE_FLUSH_IS_SAFE		1
>  
> diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> index 6732a27..b06a7a2 100644
> --- a/arch/arm64/kernel/kgdb.c
> +++ b/arch/arm64/kernel/kgdb.c
> @@ -19,6 +19,7 @@
>   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <linux/bug.h>
>  #include <linux/cpumask.h>
>  #include <linux/irq.h>
>  #include <linux/irq_work.h>
> @@ -26,6 +27,8 @@
>  #include <linux/kgdb.h>
>  #include <linux/kprobes.h>
>  #include <linux/percpu.h>
> +#include <asm/debug-monitors.h>
> +#include <asm/insn.h>
>  #include <asm/ptrace.h>
>  #include <asm/traps.h>
>  
> @@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
>  	unregister_die_notifier(&kgdb_notifier);
>  }
>  
> -/*
> - * ARM instructions are always in LE.
> - * Break instruction is encoded in LE format
> - */
> -struct kgdb_arch arch_kgdb_ops = {
> -	.gdb_bpt_instr = {
> -		KGDB_DYN_BRK_INS_BYTE(0),
> -		KGDB_DYN_BRK_INS_BYTE(1),
> -		KGDB_DYN_BRK_INS_BYTE(2),
> -		KGDB_DYN_BRK_INS_BYTE(3),
> -	}
> -};
> +struct kgdb_arch arch_kgdb_ops;
> +
> +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
> +{
> +	int err;
> +
> +	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
> +
> +	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
> +	if (err)
> +		return err;
> +
> +	return aarch64_insn_write((void *)bpt->bpt_addr,
> +			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
> +}
> +
> +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
> +{
> +	return aarch64_insn_write((void *)bpt->bpt_addr,
> +			*(u32 *)bpt->saved_instr);
> +}
> -- 
> 2.10.0
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2] arm64: kgdb: handle read-only text / modules
@ 2016-09-21  8:57   ` Mark Rutland
  0 siblings, 0 replies; 6+ messages in thread
From: Mark Rutland @ 2016-09-21  8:57 UTC (permalink / raw)
  To: linux-arm-kernel

On Wed, Sep 21, 2016 at 04:19:55PM +0900, AKASHI Takahiro wrote:
> Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
> by using aarch64_insn_write() instead of probe_kernel_write().
> See how this works:
>     commit 2f896d586610 ("arm64: use fixmap for text patching")
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jason Wessel <jason.wessel@windriver.com>
> Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
> Cc: <stable@vger.kernel.org> # 4.0-

For v3.18-v3.19, we also need commit f6242cac10427c54 ("arm64: Fix text
patching logic when using fixmap"), so as to not break the
!CONFIG_DEBUG_SET_MODULE_RONX case.

With that:

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.

> ---
>  arch/arm64/include/asm/debug-monitors.h |  2 --
>  arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
>  2 files changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
> index 4b6b3f7..b71420a 100644
> --- a/arch/arm64/include/asm/debug-monitors.h
> +++ b/arch/arm64/include/asm/debug-monitors.h
> @@ -61,8 +61,6 @@
>  
>  #define AARCH64_BREAK_KGDB_DYN_DBG	\
>  	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
> -#define KGDB_DYN_BRK_INS_BYTE(x)	\
> -	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
>  
>  #define CACHE_FLUSH_IS_SAFE		1
>  
> diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> index 6732a27..b06a7a2 100644
> --- a/arch/arm64/kernel/kgdb.c
> +++ b/arch/arm64/kernel/kgdb.c
> @@ -19,6 +19,7 @@
>   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <linux/bug.h>
>  #include <linux/cpumask.h>
>  #include <linux/irq.h>
>  #include <linux/irq_work.h>
> @@ -26,6 +27,8 @@
>  #include <linux/kgdb.h>
>  #include <linux/kprobes.h>
>  #include <linux/percpu.h>
> +#include <asm/debug-monitors.h>
> +#include <asm/insn.h>
>  #include <asm/ptrace.h>
>  #include <asm/traps.h>
>  
> @@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
>  	unregister_die_notifier(&kgdb_notifier);
>  }
>  
> -/*
> - * ARM instructions are always in LE.
> - * Break instruction is encoded in LE format
> - */
> -struct kgdb_arch arch_kgdb_ops = {
> -	.gdb_bpt_instr = {
> -		KGDB_DYN_BRK_INS_BYTE(0),
> -		KGDB_DYN_BRK_INS_BYTE(1),
> -		KGDB_DYN_BRK_INS_BYTE(2),
> -		KGDB_DYN_BRK_INS_BYTE(3),
> -	}
> -};
> +struct kgdb_arch arch_kgdb_ops;
> +
> +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
> +{
> +	int err;
> +
> +	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
> +
> +	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
> +	if (err)
> +		return err;
> +
> +	return aarch64_insn_write((void *)bpt->bpt_addr,
> +			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
> +}
> +
> +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
> +{
> +	return aarch64_insn_write((void *)bpt->bpt_addr,
> +			*(u32 *)bpt->saved_instr);
> +}
> -- 
> 2.10.0
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] arm64: kgdb: handle read-only text / modules
  2016-09-21  8:57   ` Mark Rutland
@ 2016-09-23  7:41     ` AKASHI Takahiro
  -1 siblings, 0 replies; 6+ messages in thread
From: AKASHI Takahiro @ 2016-09-23  7:41 UTC (permalink / raw)
  To: Mark Rutland
  Cc: catalin.marinas, will.deacon, jason.wessel, linux-arm-kernel,
	kgdb-bugreport, stable

On Wed, Sep 21, 2016 at 09:57:21AM +0100, Mark Rutland wrote:
> On Wed, Sep 21, 2016 at 04:19:55PM +0900, AKASHI Takahiro wrote:
> > Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
> > by using aarch64_insn_write() instead of probe_kernel_write().
> > See how this works:
> >     commit 2f896d586610 ("arm64: use fixmap for text patching")
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Cc: Jason Wessel <jason.wessel@windriver.com>
> > Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
> > Cc: <stable@vger.kernel.org> # 4.0-
> 
> For v3.18-v3.19, we also need commit f6242cac10427c54 ("arm64: Fix text
> patching logic when using fixmap"), so as to not break the
> !CONFIG_DEBUG_SET_MODULE_RONX case.

Ah, thank you.
I will post the patch as v2.1.

-Takahiro AKASHI

> With that:
> 
> Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> 
> Thanks,
> Mark.
> 
> > ---
> >  arch/arm64/include/asm/debug-monitors.h |  2 --
> >  arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
> >  2 files changed, 24 insertions(+), 14 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
> > index 4b6b3f7..b71420a 100644
> > --- a/arch/arm64/include/asm/debug-monitors.h
> > +++ b/arch/arm64/include/asm/debug-monitors.h
> > @@ -61,8 +61,6 @@
> >  
> >  #define AARCH64_BREAK_KGDB_DYN_DBG	\
> >  	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
> > -#define KGDB_DYN_BRK_INS_BYTE(x)	\
> > -	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
> >  
> >  #define CACHE_FLUSH_IS_SAFE		1
> >  
> > diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> > index 6732a27..b06a7a2 100644
> > --- a/arch/arm64/kernel/kgdb.c
> > +++ b/arch/arm64/kernel/kgdb.c
> > @@ -19,6 +19,7 @@
> >   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> >   */
> >  
> > +#include <linux/bug.h>
> >  #include <linux/cpumask.h>
> >  #include <linux/irq.h>
> >  #include <linux/irq_work.h>
> > @@ -26,6 +27,8 @@
> >  #include <linux/kgdb.h>
> >  #include <linux/kprobes.h>
> >  #include <linux/percpu.h>
> > +#include <asm/debug-monitors.h>
> > +#include <asm/insn.h>
> >  #include <asm/ptrace.h>
> >  #include <asm/traps.h>
> >  
> > @@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
> >  	unregister_die_notifier(&kgdb_notifier);
> >  }
> >  
> > -/*
> > - * ARM instructions are always in LE.
> > - * Break instruction is encoded in LE format
> > - */
> > -struct kgdb_arch arch_kgdb_ops = {
> > -	.gdb_bpt_instr = {
> > -		KGDB_DYN_BRK_INS_BYTE(0),
> > -		KGDB_DYN_BRK_INS_BYTE(1),
> > -		KGDB_DYN_BRK_INS_BYTE(2),
> > -		KGDB_DYN_BRK_INS_BYTE(3),
> > -	}
> > -};
> > +struct kgdb_arch arch_kgdb_ops;
> > +
> > +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
> > +{
> > +	int err;
> > +
> > +	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
> > +
> > +	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
> > +	if (err)
> > +		return err;
> > +
> > +	return aarch64_insn_write((void *)bpt->bpt_addr,
> > +			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
> > +}
> > +
> > +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
> > +{
> > +	return aarch64_insn_write((void *)bpt->bpt_addr,
> > +			*(u32 *)bpt->saved_instr);
> > +}
> > -- 
> > 2.10.0
> > 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2] arm64: kgdb: handle read-only text / modules
@ 2016-09-23  7:41     ` AKASHI Takahiro
  0 siblings, 0 replies; 6+ messages in thread
From: AKASHI Takahiro @ 2016-09-23  7:41 UTC (permalink / raw)
  To: linux-arm-kernel

On Wed, Sep 21, 2016 at 09:57:21AM +0100, Mark Rutland wrote:
> On Wed, Sep 21, 2016 at 04:19:55PM +0900, AKASHI Takahiro wrote:
> > Handle read-only cases (CONFIG_DEBUG_RODATA/CONFIG_DEBUG_SET_MODULE_RONX)
> > by using aarch64_insn_write() instead of probe_kernel_write().
> > See how this works:
> >     commit 2f896d586610 ("arm64: use fixmap for text patching")
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Cc: Jason Wessel <jason.wessel@windriver.com>
> > Cc: <stable@vger.kernel.org> # 3.18-3.19: 2f896d5: arm64: use fixmap
> > Cc: <stable@vger.kernel.org> # 4.0-
> 
> For v3.18-v3.19, we also need commit f6242cac10427c54 ("arm64: Fix text
> patching logic when using fixmap"), so as to not break the
> !CONFIG_DEBUG_SET_MODULE_RONX case.

Ah, thank you.
I will post the patch as v2.1.

-Takahiro AKASHI

> With that:
> 
> Reviewed-by: Mark Rutland <mark.rutland@arm.com>
> 
> Thanks,
> Mark.
> 
> > ---
> >  arch/arm64/include/asm/debug-monitors.h |  2 --
> >  arch/arm64/kernel/kgdb.c                | 36 ++++++++++++++++++++++-----------
> >  2 files changed, 24 insertions(+), 14 deletions(-)
> > 
> > diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
> > index 4b6b3f7..b71420a 100644
> > --- a/arch/arm64/include/asm/debug-monitors.h
> > +++ b/arch/arm64/include/asm/debug-monitors.h
> > @@ -61,8 +61,6 @@
> >  
> >  #define AARCH64_BREAK_KGDB_DYN_DBG	\
> >  	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
> > -#define KGDB_DYN_BRK_INS_BYTE(x)	\
> > -	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
> >  
> >  #define CACHE_FLUSH_IS_SAFE		1
> >  
> > diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> > index 6732a27..b06a7a2 100644
> > --- a/arch/arm64/kernel/kgdb.c
> > +++ b/arch/arm64/kernel/kgdb.c
> > @@ -19,6 +19,7 @@
> >   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> >   */
> >  
> > +#include <linux/bug.h>
> >  #include <linux/cpumask.h>
> >  #include <linux/irq.h>
> >  #include <linux/irq_work.h>
> > @@ -26,6 +27,8 @@
> >  #include <linux/kgdb.h>
> >  #include <linux/kprobes.h>
> >  #include <linux/percpu.h>
> > +#include <asm/debug-monitors.h>
> > +#include <asm/insn.h>
> >  #include <asm/ptrace.h>
> >  #include <asm/traps.h>
> >  
> > @@ -370,15 +373,24 @@ void kgdb_arch_exit(void)
> >  	unregister_die_notifier(&kgdb_notifier);
> >  }
> >  
> > -/*
> > - * ARM instructions are always in LE.
> > - * Break instruction is encoded in LE format
> > - */
> > -struct kgdb_arch arch_kgdb_ops = {
> > -	.gdb_bpt_instr = {
> > -		KGDB_DYN_BRK_INS_BYTE(0),
> > -		KGDB_DYN_BRK_INS_BYTE(1),
> > -		KGDB_DYN_BRK_INS_BYTE(2),
> > -		KGDB_DYN_BRK_INS_BYTE(3),
> > -	}
> > -};
> > +struct kgdb_arch arch_kgdb_ops;
> > +
> > +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
> > +{
> > +	int err;
> > +
> > +	BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
> > +
> > +	err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
> > +	if (err)
> > +		return err;
> > +
> > +	return aarch64_insn_write((void *)bpt->bpt_addr,
> > +			(u32)AARCH64_BREAK_KGDB_DYN_DBG);
> > +}
> > +
> > +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
> > +{
> > +	return aarch64_insn_write((void *)bpt->bpt_addr,
> > +			*(u32 *)bpt->saved_instr);
> > +}
> > -- 
> > 2.10.0
> > 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-09-23  7:41 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-21  7:19 [PATCH v2] arm64: kgdb: handle read-only text / modules AKASHI Takahiro
2016-09-21  7:19 ` AKASHI Takahiro
2016-09-21  8:57 ` Mark Rutland
2016-09-21  8:57   ` Mark Rutland
2016-09-23  7:41   ` AKASHI Takahiro
2016-09-23  7:41     ` AKASHI Takahiro

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.