[PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

On ia64 and ppc64, the function pointer does not point the
entry address of the function, but the address of function
discriptor (which contains the entry address and misc
data.) Since the kprobes passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors
as below.

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  Failed to find blacklist 000101315f70a000
  Failed to find blacklist 000101324c80a000
  Failed to find blacklist 0001013063f0a000
  Failed to find blacklist 000101327800a000
  Failed to find blacklist 0001013277f0a000
  Failed to find blacklist 000101315a70a000
  Failed to find blacklist 0001013277e0a000
  Failed to find blacklist 000101305a20a000
  Failed to find blacklist 0001013277d0a000
  Failed to find blacklist 00010130bdc0a000
  Failed to find blacklist 00010130dc20a000
  Failed to find blacklist 000101309a00a000
  Failed to find blacklist 0001013277c0a000
  Failed to find blacklist 0001013277b0a000
  Failed to find blacklist 0001013277a0a000
  Failed to find blacklist 000101327790a000
  Failed to find blacklist 000101303140a000
  Failed to find blacklist 0001013a3280a000

To fix this bug, this introduces function_entry() macro to
retrieve the entry address from the given function pointer,
and uses for kallsyms_lookup_size_offset() while initializing
blacklist.

Changes in v4:
 - Add kernel_text_address() check for verifying the address.
 - Moved on the latest linus tree.

Changes in v3:
 - Fix a bug to get blacklist address based on function entry
   instead of function descriptor. (Suzuki's work, Thanks!)

Changes in V2:
 - Use function_entry() macro when lookin up symbols instead
   of storing it.
 - Update for the latest -next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/ia64/include/asm/types.h    |    2 ++
 arch/powerpc/include/asm/types.h |   11 +++++++++++
 include/linux/types.h            |    4 ++++
 kernel/kprobes.c                 |   15 ++++++++++-----
 4 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
index 4c351b1..95279dd 100644
--- a/arch/ia64/include/asm/types.h
+++ b/arch/ia64/include/asm/types.h
@@ -27,5 +27,7 @@ struct fnptr {
 	unsigned long gp;
 };
 
+#define function_entry(fn) (((struct fnptr *)(fn))->ip)
+
 #endif /* !__ASSEMBLY__ */
 #endif /* _ASM_IA64_TYPES_H */
diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
index bfb6ded..8b89d65 100644
--- a/arch/powerpc/include/asm/types.h
+++ b/arch/powerpc/include/asm/types.h
@@ -25,6 +25,17 @@ typedef struct {
 	unsigned long env;
 } func_descr_t;
 
+#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
+/*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
+#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
+#else
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_TYPES_H */
diff --git a/include/linux/types.h b/include/linux/types.h
index a0bb704..3b95369 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -213,5 +213,9 @@ struct callback_head {
 };
 #define rcu_head callback_head
 
+#ifndef function_entry
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..7412535 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -32,6 +32,7 @@
  *		<prasanna@in.ibm.com> added function-return probes.
  */
 #include <linux/kprobes.h>
+#include <linux/types.h>
 #include <linux/hash.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
-	unsigned long offset = 0, size = 0;
+	unsigned long entry, offset = 0, size = 0;
 
 	for (iter = start; iter < end; iter++) {
-		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
-			pr_err("Failed to find blacklist %p\n", (void *)*iter);
+		entry = function_entry(*iter);
+
+		if (!kernel_text_address(entry) ||
+		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+			pr_err("Failed to find blacklist at %p\n",
+				(void *)entry);
 			continue;
 		}
 
 		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 		if (!ent)
 			return -ENOMEM;
-		ent->start_addr = *iter;
-		ent->end_addr = *iter + size;
+		ent->start_addr = entry;
+		ent->end_addr = entry + size;
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}

[PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

On ia64 and ppc64, the function pointer does not point the
entry address of the function, but the address of function
discriptor (which contains the entry address and misc
data.) Since the kprobes passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors
as below.

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  Failed to find blacklist 000101315f70a000
  Failed to find blacklist 000101324c80a000
  Failed to find blacklist 0001013063f0a000
  Failed to find blacklist 000101327800a000
  Failed to find blacklist 0001013277f0a000
  Failed to find blacklist 000101315a70a000
  Failed to find blacklist 0001013277e0a000
  Failed to find blacklist 000101305a20a000
  Failed to find blacklist 0001013277d0a000
  Failed to find blacklist 00010130bdc0a000
  Failed to find blacklist 00010130dc20a000
  Failed to find blacklist 000101309a00a000
  Failed to find blacklist 0001013277c0a000
  Failed to find blacklist 0001013277b0a000
  Failed to find blacklist 0001013277a0a000
  Failed to find blacklist 000101327790a000
  Failed to find blacklist 000101303140a000
  Failed to find blacklist 0001013a3280a000

To fix this bug, this introduces function_entry() macro to
retrieve the entry address from the given function pointer,
and uses for kallsyms_lookup_size_offset() while initializing
blacklist.

Changes in v4:
 - Add kernel_text_address() check for verifying the address.
 - Moved on the latest linus tree.

Changes in v3:
 - Fix a bug to get blacklist address based on function entry
   instead of function descriptor. (Suzuki's work, Thanks!)

Changes in V2:
 - Use function_entry() macro when lookin up symbols instead
   of storing it.
 - Update for the latest -next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/ia64/include/asm/types.h    |    2 ++
 arch/powerpc/include/asm/types.h |   11 +++++++++++
 include/linux/types.h            |    4 ++++
 kernel/kprobes.c                 |   15 ++++++++++-----
 4 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
index 4c351b1..95279dd 100644
--- a/arch/ia64/include/asm/types.h
+++ b/arch/ia64/include/asm/types.h
@@ -27,5 +27,7 @@ struct fnptr {
 	unsigned long gp;
 };
 
+#define function_entry(fn) (((struct fnptr *)(fn))->ip)
+
 #endif /* !__ASSEMBLY__ */
 #endif /* _ASM_IA64_TYPES_H */
diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
index bfb6ded..8b89d65 100644
--- a/arch/powerpc/include/asm/types.h
+++ b/arch/powerpc/include/asm/types.h
@@ -25,6 +25,17 @@ typedef struct {
 	unsigned long env;
 } func_descr_t;
 
+#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
+/*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
+#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
+#else
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_TYPES_H */
diff --git a/include/linux/types.h b/include/linux/types.h
index a0bb704..3b95369 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -213,5 +213,9 @@ struct callback_head {
 };
 #define rcu_head callback_head
 
+#ifndef function_entry
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..7412535 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -32,6 +32,7 @@
  *		<prasanna@in.ibm.com> added function-return probes.
  */
 #include <linux/kprobes.h>
+#include <linux/types.h>
 #include <linux/hash.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
-	unsigned long offset = 0, size = 0;
+	unsigned long entry, offset = 0, size = 0;
 
 	for (iter = start; iter < end; iter++) {
-		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
-			pr_err("Failed to find blacklist %p\n", (void *)*iter);
+		entry = function_entry(*iter);
+
+		if (!kernel_text_address(entry) ||
+		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+			pr_err("Failed to find blacklist at %p\n",
+				(void *)entry);
 			continue;
 		}
 
 		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 		if (!ent)
 			return -ENOMEM;
-		ent->start_addr = *iter;
-		ent->end_addr = *iter + size;
+		ent->start_addr = entry;
+		ent->end_addr = entry + size;
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}

[PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

On ia64 and ppc64, the function pointer does not point the
entry address of the function, but the address of function
discriptor (which contains the entry address and misc
data.) Since the kprobes passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors
as below.

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  Failed to find blacklist 000101315f70a000
  Failed to find blacklist 000101324c80a000
  Failed to find blacklist 0001013063f0a000
  Failed to find blacklist 000101327800a000
  Failed to find blacklist 0001013277f0a000
  Failed to find blacklist 000101315a70a000
  Failed to find blacklist 0001013277e0a000
  Failed to find blacklist 000101305a20a000
  Failed to find blacklist 0001013277d0a000
  Failed to find blacklist 00010130bdc0a000
  Failed to find blacklist 00010130dc20a000
  Failed to find blacklist 000101309a00a000
  Failed to find blacklist 0001013277c0a000
  Failed to find blacklist 0001013277b0a000
  Failed to find blacklist 0001013277a0a000
  Failed to find blacklist 000101327790a000
  Failed to find blacklist 000101303140a000
  Failed to find blacklist 0001013a3280a000

To fix this bug, this introduces function_entry() macro to
retrieve the entry address from the given function pointer,
and uses for kallsyms_lookup_size_offset() while initializing
blacklist.

Changes in v4:
 - Add kernel_text_address() check for verifying the address.
 - Moved on the latest linus tree.

Changes in v3:
 - Fix a bug to get blacklist address based on function entry
   instead of function descriptor. (Suzuki's work, Thanks!)

Changes in V2:
 - Use function_entry() macro when lookin up symbols instead
   of storing it.
 - Update for the latest -next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/ia64/include/asm/types.h    |    2 ++
 arch/powerpc/include/asm/types.h |   11 +++++++++++
 include/linux/types.h            |    4 ++++
 kernel/kprobes.c                 |   15 ++++++++++-----
 4 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
index 4c351b1..95279dd 100644
--- a/arch/ia64/include/asm/types.h
+++ b/arch/ia64/include/asm/types.h
@@ -27,5 +27,7 @@ struct fnptr {
 	unsigned long gp;
 };
 
+#define function_entry(fn) (((struct fnptr *)(fn))->ip)
+
 #endif /* !__ASSEMBLY__ */
 #endif /* _ASM_IA64_TYPES_H */
diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
index bfb6ded..8b89d65 100644
--- a/arch/powerpc/include/asm/types.h
+++ b/arch/powerpc/include/asm/types.h
@@ -25,6 +25,17 @@ typedef struct {
 	unsigned long env;
 } func_descr_t;
 
+#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF = 1)
+/*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
+#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
+#else
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_TYPES_H */
diff --git a/include/linux/types.h b/include/linux/types.h
index a0bb704..3b95369 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -213,5 +213,9 @@ struct callback_head {
 };
 #define rcu_head callback_head
 
+#ifndef function_entry
+#define function_entry(fn)	((unsigned long)(fn))
+#endif
+
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..7412535 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -32,6 +32,7 @@
  *		<prasanna@in.ibm.com> added function-return probes.
  */
 #include <linux/kprobes.h>
+#include <linux/types.h>
 #include <linux/hash.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
-	unsigned long offset = 0, size = 0;
+	unsigned long entry, offset = 0, size = 0;
 
 	for (iter = start; iter < end; iter++) {
-		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
-			pr_err("Failed to find blacklist %p\n", (void *)*iter);
+		entry = function_entry(*iter);
+
+		if (!kernel_text_address(entry) ||
+		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+			pr_err("Failed to find blacklist at %p\n",
+				(void *)entry);
 			continue;
 		}
 
 		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 		if (!ent)
 			return -ENOMEM;
-		ent->start_addr = *iter;
-		ent->end_addr = *iter + size;
+		ent->start_addr = entry;
+		ent->end_addr = entry + size;
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping? :)

(2014/06/20 11:23), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/ia64/include/asm/types.h    |    2 ++
>  arch/powerpc/include/asm/types.h |   11 +++++++++++
>  include/linux/types.h            |    4 ++++
>  kernel/kprobes.c                 |   15 ++++++++++-----
>  4 files changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
> index 4c351b1..95279dd 100644
> --- a/arch/ia64/include/asm/types.h
> +++ b/arch/ia64/include/asm/types.h
> @@ -27,5 +27,7 @@ struct fnptr {
>  	unsigned long gp;
>  };
>  
> +#define function_entry(fn) (((struct fnptr *)(fn))->ip)
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _ASM_IA64_TYPES_H */
> diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
> index bfb6ded..8b89d65 100644
> --- a/arch/powerpc/include/asm/types.h
> +++ b/arch/powerpc/include/asm/types.h
> @@ -25,6 +25,17 @@ typedef struct {
>  	unsigned long env;
>  } func_descr_t;
>  
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
> +#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
> +#else
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* _ASM_POWERPC_TYPES_H */
> diff --git a/include/linux/types.h b/include/linux/types.h
> index a0bb704..3b95369 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -213,5 +213,9 @@ struct callback_head {
>  };
>  #define rcu_head callback_head
>  
> +#ifndef function_entry
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /*  __ASSEMBLY__ */
>  #endif /* _LINUX_TYPES_H */
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..7412535 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = function_entry(*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping? :)

(2014/06/20 11:23), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/ia64/include/asm/types.h    |    2 ++
>  arch/powerpc/include/asm/types.h |   11 +++++++++++
>  include/linux/types.h            |    4 ++++
>  kernel/kprobes.c                 |   15 ++++++++++-----
>  4 files changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
> index 4c351b1..95279dd 100644
> --- a/arch/ia64/include/asm/types.h
> +++ b/arch/ia64/include/asm/types.h
> @@ -27,5 +27,7 @@ struct fnptr {
>  	unsigned long gp;
>  };
>  
> +#define function_entry(fn) (((struct fnptr *)(fn))->ip)
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _ASM_IA64_TYPES_H */
> diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
> index bfb6ded..8b89d65 100644
> --- a/arch/powerpc/include/asm/types.h
> +++ b/arch/powerpc/include/asm/types.h
> @@ -25,6 +25,17 @@ typedef struct {
>  	unsigned long env;
>  } func_descr_t;
>  
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
> +#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
> +#else
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* _ASM_POWERPC_TYPES_H */
> diff --git a/include/linux/types.h b/include/linux/types.h
> index a0bb704..3b95369 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -213,5 +213,9 @@ struct callback_head {
>  };
>  #define rcu_head callback_head
>  
> +#ifndef function_entry
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /*  __ASSEMBLY__ */
>  #endif /* _LINUX_TYPES_H */
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..7412535 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = function_entry(*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping? :)

(2014/06/20 11:23), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/ia64/include/asm/types.h    |    2 ++
>  arch/powerpc/include/asm/types.h |   11 +++++++++++
>  include/linux/types.h            |    4 ++++
>  kernel/kprobes.c                 |   15 ++++++++++-----
>  4 files changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
> index 4c351b1..95279dd 100644
> --- a/arch/ia64/include/asm/types.h
> +++ b/arch/ia64/include/asm/types.h
> @@ -27,5 +27,7 @@ struct fnptr {
>  	unsigned long gp;
>  };
>  
> +#define function_entry(fn) (((struct fnptr *)(fn))->ip)
> +
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _ASM_IA64_TYPES_H */
> diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
> index bfb6ded..8b89d65 100644
> --- a/arch/powerpc/include/asm/types.h
> +++ b/arch/powerpc/include/asm/types.h
> @@ -25,6 +25,17 @@ typedef struct {
>  	unsigned long env;
>  } func_descr_t;
>  
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF = 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
> +#define function_entry(fn)	(((func_descr_t *)(fn))->entry)
> +#else
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif /* _ASM_POWERPC_TYPES_H */
> diff --git a/include/linux/types.h b/include/linux/types.h
> index a0bb704..3b95369 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -213,5 +213,9 @@ struct callback_head {
>  };
>  #define rcu_head callback_head
>  
> +#ifndef function_entry
> +#define function_entry(fn)	((unsigned long)(fn))
> +#endif
> +
>  #endif /*  __ASSEMBLY__ */
>  #endif /* _LINUX_TYPES_H */
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..7412535 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = function_entry(*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> Ping? :)

Yeah sorry. I started looking at this and got dragged into another mess.

You seem to have duplicated the functionality of arch_deref_entry_point(),
which was also added for kprobes, and for the same reason - ie. because some
arches have strange function pointers. Is there some reason you can't use it?

cheers

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> Ping? :)

Yeah sorry. I started looking at this and got dragged into another mess.

You seem to have duplicated the functionality of arch_deref_entry_point(),
which was also added for kprobes, and for the same reason - ie. because some
arches have strange function pointers. Is there some reason you can't use it?

cheers

Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> Ping? :)

Yeah sorry. I started looking at this and got dragged into another mess.

You seem to have duplicated the functionality of arch_deref_entry_point(),
which was also added for kprobes, and for the same reason - ie. because some
arches have strange function pointers. Is there some reason you can't use it?

cheers

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/06/30 20:36), Michael Ellerman wrote:
> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>> Ping? :)
> 
> Yeah sorry. I started looking at this and got dragged into another mess.
> 
> You seem to have duplicated the functionality of arch_deref_entry_point(),
> which was also added for kprobes, and for the same reason - ie. because some
> arches have strange function pointers. Is there some reason you can't use it?

Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
BTW, is there any other users who need to access the actual function entry (for
kallsyms case)?

If so, I guess it'd better to merge this version and replace kprobe's local
arch_deref_entry_point() with generic function_entry() macro.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/06/30 20:36), Michael Ellerman wrote:
> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>> Ping? :)
> 
> Yeah sorry. I started looking at this and got dragged into another mess.
> 
> You seem to have duplicated the functionality of arch_deref_entry_point(),
> which was also added for kprobes, and for the same reason - ie. because some
> arches have strange function pointers. Is there some reason you can't use it?

Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
BTW, is there any other users who need to access the actual function entry (for
kallsyms case)?

If so, I guess it'd better to merge this version and replace kprobe's local
arch_deref_entry_point() with generic function_entry() macro.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/06/30 20:36), Michael Ellerman wrote:
> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>> Ping? :)
> 
> Yeah sorry. I started looking at this and got dragged into another mess.
> 
> You seem to have duplicated the functionality of arch_deref_entry_point(),
> which was also added for kprobes, and for the same reason - ie. because some
> arches have strange function pointers. Is there some reason you can't use it?

Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
BTW, is there any other users who need to access the actual function entry (for
kallsyms case)?

If so, I guess it'd better to merge this version and replace kprobe's local
arch_deref_entry_point() with generic function_entry() macro.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> (2014/06/30 20:36), Michael Ellerman wrote:
> > On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >> Ping? :)
> > 
> > Yeah sorry. I started looking at this and got dragged into another mess.
> > 
> > You seem to have duplicated the functionality of arch_deref_entry_point(),
> > which was also added for kprobes, and for the same reason - ie. because some
> > arches have strange function pointers. Is there some reason you can't use it?
> 
> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> BTW, is there any other users who need to access the actual function entry (for
> kallsyms case)?

Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
ever, so in theory by now we should have already found any cases where we need
that sort of wrapper.

cheers

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> (2014/06/30 20:36), Michael Ellerman wrote:
> > On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >> Ping? :)
> > 
> > Yeah sorry. I started looking at this and got dragged into another mess.
> > 
> > You seem to have duplicated the functionality of arch_deref_entry_point(),
> > which was also added for kprobes, and for the same reason - ie. because some
> > arches have strange function pointers. Is there some reason you can't use it?
> 
> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> BTW, is there any other users who need to access the actual function entry (for
> kallsyms case)?

Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
ever, so in theory by now we should have already found any cases where we need
that sort of wrapper.

cheers

Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> (2014/06/30 20:36), Michael Ellerman wrote:
> > On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >> Ping? :)
> > 
> > Yeah sorry. I started looking at this and got dragged into another mess.
> > 
> > You seem to have duplicated the functionality of arch_deref_entry_point(),
> > which was also added for kprobes, and for the same reason - ie. because some
> > arches have strange function pointers. Is there some reason you can't use it?
> 
> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> BTW, is there any other users who need to access the actual function entry (for
> kallsyms case)?

Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
ever, so in theory by now we should have already found any cases where we need
that sort of wrapper.

cheers

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 13:41), Michael Ellerman wrote:
> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>> (2014/06/30 20:36), Michael Ellerman wrote:
>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>> Ping? :)
>>>
>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>
>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>> which was also added for kprobes, and for the same reason - ie. because some
>>> arches have strange function pointers. Is there some reason you can't use it?
>>
>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>> BTW, is there any other users who need to access the actual function entry (for
>> kallsyms case)?
> 
> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> ever, so in theory by now we should have already found any cases where we need
> that sort of wrapper.

OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
patch which update to support PPC64 ABIv2.

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 13:41), Michael Ellerman wrote:
> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>> (2014/06/30 20:36), Michael Ellerman wrote:
>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>> Ping? :)
>>>
>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>
>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>> which was also added for kprobes, and for the same reason - ie. because some
>>> arches have strange function pointers. Is there some reason you can't use it?
>>
>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>> BTW, is there any other users who need to access the actual function entry (for
>> kallsyms case)?
> 
> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> ever, so in theory by now we should have already found any cases where we need
> that sort of wrapper.

OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
patch which update to support PPC64 ABIv2.

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 13:41), Michael Ellerman wrote:
> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>> (2014/06/30 20:36), Michael Ellerman wrote:
>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>> Ping? :)
>>>
>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>
>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>> which was also added for kprobes, and for the same reason - ie. because some
>>> arches have strange function pointers. Is there some reason you can't use it?
>>
>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>> BTW, is there any other users who need to access the actual function entry (for
>> kallsyms case)?
> 
> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> ever, so in theory by now we should have already found any cases where we need
> that sort of wrapper.

OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
patch which update to support PPC64 ABIv2.

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
> (2014/07/02 13:41), Michael Ellerman wrote:
> > On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> >> (2014/06/30 20:36), Michael Ellerman wrote:
> >>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >>>> Ping? :)
> >>>
> >>> Yeah sorry. I started looking at this and got dragged into another mess.
> >>>
> >>> You seem to have duplicated the functionality of arch_deref_entry_point(),
> >>> which was also added for kprobes, and for the same reason - ie. because some
> >>> arches have strange function pointers. Is there some reason you can't use it?
> >>
> >> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> >> BTW, is there any other users who need to access the actual function entry (for
> >> kallsyms case)?
> > 
> > Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> > ever, so in theory by now we should have already found any cases where we need
> > that sort of wrapper.
> 
> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
> patch which update to support PPC64 ABIv2.

I've already done the latter:

  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

cheers

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
> (2014/07/02 13:41), Michael Ellerman wrote:
> > On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> >> (2014/06/30 20:36), Michael Ellerman wrote:
> >>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >>>> Ping? :)
> >>>
> >>> Yeah sorry. I started looking at this and got dragged into another mess.
> >>>
> >>> You seem to have duplicated the functionality of arch_deref_entry_point(),
> >>> which was also added for kprobes, and for the same reason - ie. because some
> >>> arches have strange function pointers. Is there some reason you can't use it?
> >>
> >> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> >> BTW, is there any other users who need to access the actual function entry (for
> >> kallsyms case)?
> > 
> > Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> > ever, so in theory by now we should have already found any cases where we need
> > that sort of wrapper.
> 
> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
> patch which update to support PPC64 ABIv2.

I've already done the latter:

  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

cheers

Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
> (2014/07/02 13:41), Michael Ellerman wrote:
> > On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
> >> (2014/06/30 20:36), Michael Ellerman wrote:
> >>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
> >>>> Ping? :)
> >>>
> >>> Yeah sorry. I started looking at this and got dragged into another mess.
> >>>
> >>> You seem to have duplicated the functionality of arch_deref_entry_point(),
> >>> which was also added for kprobes, and for the same reason - ie. because some
> >>> arches have strange function pointers. Is there some reason you can't use it?
> >>
> >> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
> >> BTW, is there any other users who need to access the actual function entry (for
> >> kallsyms case)?
> > 
> > Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
> > ever, so in theory by now we should have already found any cases where we need
> > that sort of wrapper.
> 
> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
> patch which update to support PPC64 ABIv2.

I've already done the latter:

  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id/0143c91d30823f6f6e7d94d7fa818f7ab18a18

cheers

[PATCH v5 1/2] kprobes/powerpc: Fix arch_deref_entry_point to support ABIv2

[Masami Hiramatsu]

Since PowerPC64 ABIv2 doesn't have function descriptor
any more, arch_deref_entry_point(), which returns function
entry point from function descriptor, should be updated.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anoop Thomas Mathew <atm@profoundis.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/kprobes.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 90fab64..72a1034 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -491,7 +491,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
 	return ret;
 }
 
-#ifdef CONFIG_PPC64
+#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
+/*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
 unsigned long arch_deref_entry_point(void *entry)
 {
 	return ((func_descr_t *)entry)->entry;

[PATCH v5 1/2] kprobes/powerpc: Fix arch_deref_entry_point to support ABIv2

[Masami Hiramatsu]

Since PowerPC64 ABIv2 doesn't have function descriptor
any more, arch_deref_entry_point(), which returns function
entry point from function descriptor, should be updated.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anoop Thomas Mathew <atm@profoundis.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/kprobes.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 90fab64..72a1034 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -491,7 +491,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
 	return ret;
 }
 
-#ifdef CONFIG_PPC64
+#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
+/*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
 unsigned long arch_deref_entry_point(void *entry)
 {
 	return ((func_descr_t *)entry)->entry;

[PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

On ia64 and ppc64, the function pointer does not point the
entry address of the function, but the address of function
discriptor (which contains the entry address and misc
data.) Since the kprobes passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors
as below.

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  Failed to find blacklist 000101315f70a000
  Failed to find blacklist 000101324c80a000
  Failed to find blacklist 0001013063f0a000
  Failed to find blacklist 000101327800a000
  Failed to find blacklist 0001013277f0a000
  Failed to find blacklist 000101315a70a000
  Failed to find blacklist 0001013277e0a000
  Failed to find blacklist 000101305a20a000
  Failed to find blacklist 0001013277d0a000
  Failed to find blacklist 00010130bdc0a000
  Failed to find blacklist 00010130dc20a000
  Failed to find blacklist 000101309a00a000
  Failed to find blacklist 0001013277c0a000
  Failed to find blacklist 0001013277b0a000
  Failed to find blacklist 0001013277a0a000
  Failed to find blacklist 000101327790a000
  Failed to find blacklist 000101303140a000
  Failed to find blacklist 0001013a3280a000

To fix this bug, this introduces function_entry() macro to
retrieve the entry address from the given function pointer,
and uses for kallsyms_lookup_size_offset() while initializing
blacklist.

Changes in v5:
 - Use arch_deref_entry_point() instead of function_entry().

Changes in v4:
 - Add kernel_text_address() check for verifying the address.
 - Moved on the latest linus tree.

Changes in v3:
 - Fix a bug to get blacklist address based on function entry
   instead of function descriptor. (Suzuki's work, Thanks!)

Changes in V2:
 - Use function_entry() macro when lookin up symbols instead
   of storing it.
 - Update for the latest -next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
---
 kernel/kprobes.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..ec370cc 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -32,6 +32,7 @@
  *		<prasanna@in.ibm.com> added function-return probes.
  */
 #include <linux/kprobes.h>
+#include <linux/types.h>
 #include <linux/hash.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
-	unsigned long offset = 0, size = 0;
+	unsigned long entry, offset = 0, size = 0;
 
 	for (iter = start; iter < end; iter++) {
-		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
-			pr_err("Failed to find blacklist %p\n", (void *)*iter);
+		entry = arch_deref_entry_point((void *)*iter);
+
+		if (!kernel_text_address(entry) ||
+		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+			pr_err("Failed to find blacklist at %p\n",
+				(void *)entry);
 			continue;
 		}
 
 		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 		if (!ent)
 			return -ENOMEM;
-		ent->start_addr = *iter;
-		ent->end_addr = *iter + size;
+		ent->start_addr = entry;
+		ent->end_addr = entry + size;
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}

[PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

On ia64 and ppc64, the function pointer does not point the
entry address of the function, but the address of function
discriptor (which contains the entry address and misc
data.) Since the kprobes passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors
as below.

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  Failed to find blacklist 000101315f70a000
  Failed to find blacklist 000101324c80a000
  Failed to find blacklist 0001013063f0a000
  Failed to find blacklist 000101327800a000
  Failed to find blacklist 0001013277f0a000
  Failed to find blacklist 000101315a70a000
  Failed to find blacklist 0001013277e0a000
  Failed to find blacklist 000101305a20a000
  Failed to find blacklist 0001013277d0a000
  Failed to find blacklist 00010130bdc0a000
  Failed to find blacklist 00010130dc20a000
  Failed to find blacklist 000101309a00a000
  Failed to find blacklist 0001013277c0a000
  Failed to find blacklist 0001013277b0a000
  Failed to find blacklist 0001013277a0a000
  Failed to find blacklist 000101327790a000
  Failed to find blacklist 000101303140a000
  Failed to find blacklist 0001013a3280a000

To fix this bug, this introduces function_entry() macro to
retrieve the entry address from the given function pointer,
and uses for kallsyms_lookup_size_offset() while initializing
blacklist.

Changes in v5:
 - Use arch_deref_entry_point() instead of function_entry().

Changes in v4:
 - Add kernel_text_address() check for verifying the address.
 - Moved on the latest linus tree.

Changes in v3:
 - Fix a bug to get blacklist address based on function entry
   instead of function descriptor. (Suzuki's work, Thanks!)

Changes in V2:
 - Use function_entry() macro when lookin up symbols instead
   of storing it.
 - Update for the latest -next.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
---
 kernel/kprobes.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3214289..ec370cc 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -32,6 +32,7 @@
  *		<prasanna@in.ibm.com> added function-return probes.
  */
 #include <linux/kprobes.h>
+#include <linux/types.h>
 #include <linux/hash.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
 {
 	unsigned long *iter;
 	struct kprobe_blacklist_entry *ent;
-	unsigned long offset = 0, size = 0;
+	unsigned long entry, offset = 0, size = 0;
 
 	for (iter = start; iter < end; iter++) {
-		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
-			pr_err("Failed to find blacklist %p\n", (void *)*iter);
+		entry = arch_deref_entry_point((void *)*iter);
+
+		if (!kernel_text_address(entry) ||
+		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+			pr_err("Failed to find blacklist at %p\n",
+				(void *)entry);
 			continue;
 		}
 
 		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
 		if (!ent)
 			return -ENOMEM;
-		ent->start_addr = *iter;
-		ent->end_addr = *iter + size;
+		ent->start_addr = entry;
+		ent->end_addr = entry + size;
 		INIT_LIST_HEAD(&ent->list);
 		list_add_tail(&ent->list, &kprobe_blacklist);
 	}

Re: Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 15:56), Michael Ellerman wrote:
> On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
>> (2014/07/02 13:41), Michael Ellerman wrote:
>>> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>>>> (2014/06/30 20:36), Michael Ellerman wrote:
>>>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>>>> Ping? :)
>>>>>
>>>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>>>
>>>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>>>> which was also added for kprobes, and for the same reason - ie. because some
>>>>> arches have strange function pointers. Is there some reason you can't use it?
>>>>
>>>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>>>> BTW, is there any other users who need to access the actual function entry (for
>>>> kallsyms case)?
>>>
>>> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
>>> ever, so in theory by now we should have already found any cases where we need
>>> that sort of wrapper.
>>
>> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
>> patch which update to support PPC64 ABIv2.
> 
> I've already done the latter:
> 
>   https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

Oh, thanks!

In that case, my 1/2 patch should be dropped.


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 15:56), Michael Ellerman wrote:
> On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
>> (2014/07/02 13:41), Michael Ellerman wrote:
>>> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>>>> (2014/06/30 20:36), Michael Ellerman wrote:
>>>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>>>> Ping? :)
>>>>>
>>>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>>>
>>>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>>>> which was also added for kprobes, and for the same reason - ie. because some
>>>>> arches have strange function pointers. Is there some reason you can't use it?
>>>>
>>>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>>>> BTW, is there any other users who need to access the actual function entry (for
>>>> kallsyms case)?
>>>
>>> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
>>> ever, so in theory by now we should have already found any cases where we need
>>> that sort of wrapper.
>>
>> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
>> patch which update to support PPC64 ABIv2.
> 
> I've already done the latter:
> 
>   https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

Oh, thanks!

In that case, my 1/2 patch should be dropped.


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: Re: [PATCH v4] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/02 15:56), Michael Ellerman wrote:
> On Wed, 2014-07-02 at 15:39 +0900, Masami Hiramatsu wrote:
>> (2014/07/02 13:41), Michael Ellerman wrote:
>>> On Tue, 2014-07-01 at 11:21 +0900, Masami Hiramatsu wrote:
>>>> (2014/06/30 20:36), Michael Ellerman wrote:
>>>>> On Mon, 2014-06-30 at 12:14 +0900, Masami Hiramatsu wrote:
>>>>>> Ping? :)
>>>>>
>>>>> Yeah sorry. I started looking at this and got dragged into another mess.
>>>>>
>>>>> You seem to have duplicated the functionality of arch_deref_entry_point(),
>>>>> which was also added for kprobes, and for the same reason - ie. because some
>>>>> arches have strange function pointers. Is there some reason you can't use it?
>>>>
>>>> Ah, right! Hmm, it seems some more work to update it. but basically, we can do.
>>>> BTW, is there any other users who need to access the actual function entry (for
>>>> kallsyms case)?
>>>
>>> Not that I'm aware of. We have had function descriptors on 64-bit powerpc for
>>> ever, so in theory by now we should have already found any cases where we need
>>> that sort of wrapper.
>>
>> OK, then I'll update this patch to use arch_deref_entry_point(), and add additional
>> patch which update to support PPC64 ABIv2.
> 
> I've already done the latter:
> 
>   https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id/0143c91d30823f6f6e7d94d7fa818f7ab18a18

Oh, thanks!

In that case, my 1/2 patch should be dropped.


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 1/2] kprobes/powerpc: Fix arch_deref_entry_point to support ABIv2

[Masami Hiramatsu]

(2014/07/02 16:00), Masami Hiramatsu wrote:
> Since PowerPC64 ABIv2 doesn't have function descriptor
> any more, arch_deref_entry_point(), which returns function
> entry point from function descriptor, should be updated.

Please ignore this patch, since it is already fixed by Michael

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

We only need 2/2.

Thank you,



> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Anoop Thomas Mathew <atm@profoundis.com>
> Cc: Jiri Kosina <jkosina@suse.cz>
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/powerpc/kernel/kprobes.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
> index 90fab64..72a1034 100644
> --- a/arch/powerpc/kernel/kprobes.c
> +++ b/arch/powerpc/kernel/kprobes.c
> @@ -491,7 +491,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
>  	return ret;
>  }
>  
> -#ifdef CONFIG_PPC64
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
>  unsigned long arch_deref_entry_point(void *entry)
>  {
>  	return ((func_descr_t *)entry)->entry;
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 1/2] kprobes/powerpc: Fix arch_deref_entry_point to support ABIv2

[Masami Hiramatsu]

(2014/07/02 16:00), Masami Hiramatsu wrote:
> Since PowerPC64 ABIv2 doesn't have function descriptor
> any more, arch_deref_entry_point(), which returns function
> entry point from function descriptor, should be updated.

Please ignore this patch, since it is already fixed by Michael

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2f0143c91d30823f6f6e7d94d7fa818f7ab18a18

We only need 2/2.

Thank you,



> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Anoop Thomas Mathew <atm@profoundis.com>
> Cc: Jiri Kosina <jkosina@suse.cz>
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/powerpc/kernel/kprobes.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
> index 90fab64..72a1034 100644
> --- a/arch/powerpc/kernel/kprobes.c
> +++ b/arch/powerpc/kernel/kprobes.c
> @@ -491,7 +491,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
>  	return ret;
>  }
>  
> -#ifdef CONFIG_PPC64
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
>  unsigned long arch_deref_entry_point(void *entry)
>  {
>  	return ((func_descr_t *)entry)->entry;
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping?

This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Thank you,

(2014/07/02 16:00), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  kernel/kprobes.c |   15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..ec370cc 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = arch_deref_entry_point((void *)*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping?

This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Thank you,

(2014/07/02 16:00), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  kernel/kprobes.c |   15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..ec370cc 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = arch_deref_entry_point((void *)*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

Ping?

This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Thank you,

(2014/07/02 16:00), Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
>  kernel/kprobes.c |   15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 3214289..ec370cc 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
>   *		<prasanna@in.ibm.com> added function-return probes.
>   */
>  #include <linux/kprobes.h>
> +#include <linux/types.h>
>  #include <linux/hash.h>
>  #include <linux/init.h>
>  #include <linux/slab.h>
> @@ -2037,19 +2038,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
>  {
>  	unsigned long *iter;
>  	struct kprobe_blacklist_entry *ent;
> -	unsigned long offset = 0, size = 0;
> +	unsigned long entry, offset = 0, size = 0;
>  
>  	for (iter = start; iter < end; iter++) {
> -		if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> -			pr_err("Failed to find blacklist %p\n", (void *)*iter);
> +		entry = arch_deref_entry_point((void *)*iter);
> +
> +		if (!kernel_text_address(entry) ||
> +		    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
> +			pr_err("Failed to find blacklist at %p\n",
> +				(void *)entry);
>  			continue;
>  		}
>  
>  		ent = kmalloc(sizeof(*ent), GFP_KERNEL);
>  		if (!ent)
>  			return -ENOMEM;
> -		ent->start_addr = *iter;
> -		ent->end_addr = *iter + size;
> +		ent->start_addr = entry;
> +		ent->end_addr = entry + size;
>  		INIT_LIST_HEAD(&ent->list);
>  		list_add_tail(&ent->list, &kprobe_blacklist);
>  	}
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 


-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Tony Luck]

On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
<masami.hiramatsu.pt@hitachi.com> wrote:
> Ping?
>
> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Is somebody going to push this upstream? Another week has gone by,
we are at -rc5, and I'm still seeing the

  Failed to find blacklist a00000010133b150

messages on ia64.

-Tony

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Tony Luck]

On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
<masami.hiramatsu.pt@hitachi.com> wrote:
> Ping?
>
> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Is somebody going to push this upstream? Another week has gone by,
we are at -rc5, and I'm still seeing the

  Failed to find blacklist a00000010133b150

messages on ia64.

-Tony

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Tony Luck]

On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
<masami.hiramatsu.pt@hitachi.com> wrote:
> Ping?
>
> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.

Is somebody going to push this upstream? Another week has gone by,
we are at -rc5, and I'm still seeing the

  Failed to find blacklist a00000010133b150

messages on ia64.

-Tony

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> <masami.hiramatsu.pt@hitachi.com> wrote:
> > Ping?
> >
> > This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> 
> Is somebody going to push this upstream? Another week has gone by,
> we are at -rc5, and I'm still seeing the
> 
>   Failed to find blacklist a00000010133b150
> 
> messages on ia64.

I don't see those messages on ppc64, I don't know where the original report
that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> <masami.hiramatsu.pt@hitachi.com> wrote:
> > Ping?
> >
> > This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> 
> Is somebody going to push this upstream? Another week has gone by,
> we are at -rc5, and I'm still seeing the
> 
>   Failed to find blacklist a00000010133b150
> 
> messages on ia64.

I don't see those messages on ppc64, I don't know where the original report
that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> <masami.hiramatsu.pt@hitachi.com> wrote:
> > Ping?
> >
> > This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> 
> Is somebody going to push this upstream? Another week has gone by,
> we are at -rc5, and I'm still seeing the
> 
>   Failed to find blacklist a00000010133b150
> 
> messages on ia64.

I don't see those messages on ppc64, I don't know where the original report
that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

cheers

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 11:11), Michael Ellerman wrote:
> On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
>> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
>> <masami.hiramatsu.pt@hitachi.com> wrote:
>>> Ping?
>>>
>>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
>>
>> Is somebody going to push this upstream? Another week has gone by,
>> we are at -rc5, and I'm still seeing the
>>
>>   Failed to find blacklist a00000010133b150
>>
>> messages on ia64.
> 
> I don't see those messages on ppc64, I don't know where the original report
> that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

Right, on ppc64(ABIv1) it may be silently failed. Because each function
descriptor has another entry on kallsyms, original code can't detect
that. On the other hand, ia64's function descriptors have no entries,
so it can detect the failure on boot.

This patch adds new detection code using kernel_text_address() and
translates function descriptor to function entry.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 11:11), Michael Ellerman wrote:
> On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
>> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
>> <masami.hiramatsu.pt@hitachi.com> wrote:
>>> Ping?
>>>
>>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
>>
>> Is somebody going to push this upstream? Another week has gone by,
>> we are at -rc5, and I'm still seeing the
>>
>>   Failed to find blacklist a00000010133b150
>>
>> messages on ia64.
> 
> I don't see those messages on ppc64, I don't know where the original report
> that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

Right, on ppc64(ABIv1) it may be silently failed. Because each function
descriptor has another entry on kallsyms, original code can't detect
that. On the other hand, ia64's function descriptors have no entries,
so it can detect the failure on boot.

This patch adds new detection code using kernel_text_address() and
translates function descriptor to function entry.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 11:11), Michael Ellerman wrote:
> On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
>> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
>> <masami.hiramatsu.pt@hitachi.com> wrote:
>>> Ping?
>>>
>>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
>>
>> Is somebody going to push this upstream? Another week has gone by,
>> we are at -rc5, and I'm still seeing the
>>
>>   Failed to find blacklist a00000010133b150
>>
>> messages on ia64.
> 
> I don't see those messages on ppc64, I don't know where the original report
> that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.

Right, on ppc64(ABIv1) it may be silently failed. Because each function
descriptor has another entry on kallsyms, original code can't detect
that. On the other hand, ia64's function descriptors have no entries,
so it can detect the failure on boot.

This patch adds new detection code using kernel_text_address() and
translates function descriptor to function entry.

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-15 at 11:24 +0900, Masami Hiramatsu wrote:
> (2014/07/15 11:11), Michael Ellerman wrote:
> > On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> >> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> >> <masami.hiramatsu.pt@hitachi.com> wrote:
> >>> Ping?
> >>>
> >>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> >>
> >> Is somebody going to push this upstream? Another week has gone by,
> >> we are at -rc5, and I'm still seeing the
> >>
> >>   Failed to find blacklist a00000010133b150
> >>
> >> messages on ia64.
> > 
> > I don't see those messages on ppc64, I don't know where the original report
> > that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.
> 
> Right, on ppc64(ABIv1) it may be silently failed. Because each function
> descriptor has another entry on kallsyms, original code can't detect
> that. 

OK, that would have been good to know :)

It's actually much worse than you describe. On ppc64 (ABIv1) we are
successfully blacklisting the function descriptors. But that doesn't prevent
you from probing the text address. So basically NOKPROBE_SYMBOL() does nothing
useful for us.

$ head -2 ../kprobes/blacklist 
0xc000000000d4cff8-0xc000000000d4d010	notify_die
0xc000000000d4cf80-0xc000000000d4cf98	atomic_notifier_call_chain
$ echo "p:atomic_notifier_call_chain .atomic_notifier_call_chain" > kprobe_events
$ echo 1 > events/kprobes/enable 
$ ls
available_events      instances       saved_cmdlines       trace_options
available_tracers     kprobe_events   saved_cmdlines_size  trace_pipe
buffer_size_kb        kprobe_profile  set_event            tracing_cpumask
buffer_total_size_kb  options         snapshot             tracing_max_latency
current_tracer        per_cpu         trace                tracing_on
events                printk_formats  trace_clock          tracing_thresh
free_buffer           README          trace_marker
$ Dumping ftrace buffer:
cpu 0x2: Vector: 400 (Instruction Access) at [c0000001defaf830]
    pc: 0000000000000000
    lr: 0000000000000001
    sp: c0000001defafab0
   msr: 8000000140009032
  current = 0xc0000001def57e40
  paca    = 0xc00000000fe00800	 softe: 0	 irq_happened: 0x01
    pid   = 1, comm = swapper/2
cpu 0x3: Vector: 400 (Instruction Access) at [c0000001ddbcc640]
    pc: 0000000000000000
    lr: 0000000000000000
    sp: c0000001ddbcc8c0
   msr: 8000000040001032
  current = 0xc0000001def5a100
  paca    = 0xc00000000fe00c00	 softe: 0	 irq_happened: 0x01
    pid   = -554326528, comm = 

Dead machine.


With your patch:

$ head -2 kprobes/blacklist 
0xc0000000000bf860-0xc0000000000bf8b0	.notify_die
0xc0000000000bf750-0xc0000000000bf780	.atomic_notifier_call_chain

$ echo "p:notify_die .notify_die" > tracing/kprobe_events
-bash: echo: write error: Invalid argument

So that is much better.

cheers

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-15 at 11:24 +0900, Masami Hiramatsu wrote:
> (2014/07/15 11:11), Michael Ellerman wrote:
> > On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> >> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> >> <masami.hiramatsu.pt@hitachi.com> wrote:
> >>> Ping?
> >>>
> >>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> >>
> >> Is somebody going to push this upstream? Another week has gone by,
> >> we are at -rc5, and I'm still seeing the
> >>
> >>   Failed to find blacklist a00000010133b150
> >>
> >> messages on ia64.
> > 
> > I don't see those messages on ppc64, I don't know where the original report
> > that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.
> 
> Right, on ppc64(ABIv1) it may be silently failed. Because each function
> descriptor has another entry on kallsyms, original code can't detect
> that. 

OK, that would have been good to know :)

It's actually much worse than you describe. On ppc64 (ABIv1) we are
successfully blacklisting the function descriptors. But that doesn't prevent
you from probing the text address. So basically NOKPROBE_SYMBOL() does nothing
useful for us.

$ head -2 ../kprobes/blacklist 
0xc000000000d4cff8-0xc000000000d4d010	notify_die
0xc000000000d4cf80-0xc000000000d4cf98	atomic_notifier_call_chain
$ echo "p:atomic_notifier_call_chain .atomic_notifier_call_chain" > kprobe_events
$ echo 1 > events/kprobes/enable 
$ ls
available_events      instances       saved_cmdlines       trace_options
available_tracers     kprobe_events   saved_cmdlines_size  trace_pipe
buffer_size_kb        kprobe_profile  set_event            tracing_cpumask
buffer_total_size_kb  options         snapshot             tracing_max_latency
current_tracer        per_cpu         trace                tracing_on
events                printk_formats  trace_clock          tracing_thresh
free_buffer           README          trace_marker
$ Dumping ftrace buffer:
cpu 0x2: Vector: 400 (Instruction Access) at [c0000001defaf830]
    pc: 0000000000000000
    lr: 0000000000000001
    sp: c0000001defafab0
   msr: 8000000140009032
  current = 0xc0000001def57e40
  paca    = 0xc00000000fe00800	 softe: 0	 irq_happened: 0x01
    pid   = 1, comm = swapper/2
cpu 0x3: Vector: 400 (Instruction Access) at [c0000001ddbcc640]
    pc: 0000000000000000
    lr: 0000000000000000
    sp: c0000001ddbcc8c0
   msr: 8000000040001032
  current = 0xc0000001def5a100
  paca    = 0xc00000000fe00c00	 softe: 0	 irq_happened: 0x01
    pid   = -554326528, comm = 

Dead machine.


With your patch:

$ head -2 kprobes/blacklist 
0xc0000000000bf860-0xc0000000000bf8b0	.notify_die
0xc0000000000bf750-0xc0000000000bf780	.atomic_notifier_call_chain

$ echo "p:notify_die .notify_die" > tracing/kprobe_events
-bash: echo: write error: Invalid argument

So that is much better.

cheers

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Tue, 2014-07-15 at 11:24 +0900, Masami Hiramatsu wrote:
> (2014/07/15 11:11), Michael Ellerman wrote:
> > On Mon, 2014-07-14 at 10:17 -0700, Tony Luck wrote:
> >> On Tue, Jul 8, 2014 at 5:07 AM, Masami Hiramatsu
> >> <masami.hiramatsu.pt@hitachi.com> wrote:
> >>> Ping?
> >>>
> >>> This patch can be applied without 1/2, and will fix ia64/ppc64 problem.
> >>
> >> Is somebody going to push this upstream? Another week has gone by,
> >> we are at -rc5, and I'm still seeing the
> >>
> >>   Failed to find blacklist a00000010133b150
> >>
> >> messages on ia64.
> > 
> > I don't see those messages on ppc64, I don't know where the original report
> > that it was broken on ppc64 came from. So I'm a bit lukewarm on the patch.
> 
> Right, on ppc64(ABIv1) it may be silently failed. Because each function
> descriptor has another entry on kallsyms, original code can't detect
> that. 

OK, that would have been good to know :)

It's actually much worse than you describe. On ppc64 (ABIv1) we are
successfully blacklisting the function descriptors. But that doesn't prevent
you from probing the text address. So basically NOKPROBE_SYMBOL() does nothing
useful for us.

$ head -2 ../kprobes/blacklist 
0xc000000000d4cff8-0xc000000000d4d010	notify_die
0xc000000000d4cf80-0xc000000000d4cf98	atomic_notifier_call_chain
$ echo "p:atomic_notifier_call_chain .atomic_notifier_call_chain" > kprobe_events
$ echo 1 > events/kprobes/enable 
$ ls
available_events      instances       saved_cmdlines       trace_options
available_tracers     kprobe_events   saved_cmdlines_size  trace_pipe
buffer_size_kb        kprobe_profile  set_event            tracing_cpumask
buffer_total_size_kb  options         snapshot             tracing_max_latency
current_tracer        per_cpu         trace                tracing_on
events                printk_formats  trace_clock          tracing_thresh
free_buffer           README          trace_marker
$ Dumping ftrace buffer:
cpu 0x2: Vector: 400 (Instruction Access) at [c0000001defaf830]
    pc: 0000000000000000
    lr: 0000000000000001
    sp: c0000001defafab0
   msr: 8000000140009032
  current = 0xc0000001def57e40
  paca    = 0xc00000000fe00800	 softe: 0	 irq_happened: 0x01
    pid   = 1, comm = swapper/2
cpu 0x3: Vector: 400 (Instruction Access) at [c0000001ddbcc640]
    pc: 0000000000000000
    lr: 0000000000000000
    sp: c0000001ddbcc8c0
   msr: 8000000040001032
  current = 0xc0000001def5a100
  paca    = 0xc00000000fe00c00	 softe: 0	 irq_happened: 0x01
    pid   = -554326528, comm = 

Dead machine.


With your patch:

$ head -2 kprobes/blacklist 
0xc0000000000bf860-0xc0000000000bf8b0	.notify_die
0xc0000000000bf750-0xc0000000000bf780	.atomic_notifier_call_chain

$ echo "p:notify_die .notify_die" > tracing/kprobe_events
-bash: echo: write error: Invalid argument

So that is much better.

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 07:00 +0000, Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>

Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)

Ben, can you take this in your tree?

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 07:00 +0000, Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>

Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)

Ben, can you take this in your tree?

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Michael Ellerman]

On Wed, 2014-07-02 at 07:00 +0000, Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
> 
>   Failed to find blacklist 0001013168300000
>   Failed to find blacklist 0001013000f0a000
>   Failed to find blacklist 000101315f70a000
>   Failed to find blacklist 000101324c80a000
>   Failed to find blacklist 0001013063f0a000
>   Failed to find blacklist 000101327800a000
>   Failed to find blacklist 0001013277f0a000
>   Failed to find blacklist 000101315a70a000
>   Failed to find blacklist 0001013277e0a000
>   Failed to find blacklist 000101305a20a000
>   Failed to find blacklist 0001013277d0a000
>   Failed to find blacklist 00010130bdc0a000
>   Failed to find blacklist 00010130dc20a000
>   Failed to find blacklist 000101309a00a000
>   Failed to find blacklist 0001013277c0a000
>   Failed to find blacklist 0001013277b0a000
>   Failed to find blacklist 0001013277a0a000
>   Failed to find blacklist 000101327790a000
>   Failed to find blacklist 000101303140a000
>   Failed to find blacklist 0001013a3280a000
> 
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
> 
> Changes in v5:
>  - Use arch_deref_entry_point() instead of function_entry().
> 
> Changes in v4:
>  - Add kernel_text_address() check for verifying the address.
>  - Moved on the latest linus tree.
> 
> Changes in v3:
>  - Fix a bug to get blacklist address based on function entry
>    instead of function descriptor. (Suzuki's work, Thanks!)
> 
> Changes in V2:
>  - Use function_entry() macro when lookin up symbols instead
>    of storing it.
>  - Update for the latest -next.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>

Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)

Ben, can you take this in your tree?

cheers

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Benjamin Herrenschmidt]

On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:

> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Reported-by: Tony Luck <tony.luck@gmail.com>
> > Tested-by: Tony Luck <tony.luck@intel.com>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> 
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> 
> Ben, can you take this in your tree?

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

That looks more like generic material. Do we have a kprobes maintainer ?
Andrew, do you want to take this ?

I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
cares :-)

Cheers,
Ben.

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Benjamin Herrenschmidt]

On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:

> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Reported-by: Tony Luck <tony.luck@gmail.com>
> > Tested-by: Tony Luck <tony.luck@intel.com>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> 
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> 
> Ben, can you take this in your tree?

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

That looks more like generic material. Do we have a kprobes maintainer ?
Andrew, do you want to take this ?

I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
cares :-)

Cheers,
Ben.

Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Benjamin Herrenschmidt]

On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:

> > Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Reported-by: Tony Luck <tony.luck@gmail.com>
> > Tested-by: Tony Luck <tony.luck@intel.com>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> 
> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> 
> Ben, can you take this in your tree?

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

That looks more like generic material. Do we have a kprobes maintainer ?
Andrew, do you want to take this ?

I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
cares :-)

Cheers,
Ben.

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> 
>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>
>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>
>> Ben, can you take this in your tree?
> 
> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> That looks more like generic material. Do we have a kprobes maintainer ?
> Andrew, do you want to take this ?

Yeah, I usually use Ingo's tip tree for kprobes maintenance.
Ingo, could you pull this as urgent-for-linus patch?

> I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
> cares :-)

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> 
>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>
>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>
>> Ben, can you take this in your tree?
> 
> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> That looks more like generic material. Do we have a kprobes maintainer ?
> Andrew, do you want to take this ?

Yeah, I usually use Ingo's tip tree for kprobes maintenance.
Ingo, could you pull this as urgent-for-linus patch?

> I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
> cares :-)

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> 
>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>
>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>
>> Ben, can you take this in your tree?
> 
> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> That looks more like generic material. Do we have a kprobes maintainer ?
> Andrew, do you want to take this ?

Yeah, I usually use Ingo's tip tree for kprobes maintenance.
Ingo, could you pull this as urgent-for-linus patch?

> I'm happy to put it in powerpc and send it to Linus tomorrow if nobody
> cares :-)

Thank you!

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> > On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> > 
> >>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>
> >> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>
> >> Ben, can you take this in your tree?
> > 
> > Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > 
> > That looks more like generic material. Do we have a kprobes maintainer ?
> > Andrew, do you want to take this ?
> 
> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> Ingo, could you pull this as urgent-for-linus patch?

Mind resending it in a separate thread with all acks added, etc?

Thanks,

	Ingo

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> > On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> > 
> >>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>
> >> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>
> >> Ben, can you take this in your tree?
> > 
> > Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > 
> > That looks more like generic material. Do we have a kprobes maintainer ?
> > Andrew, do you want to take this ?
> 
> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> Ingo, could you pull this as urgent-for-linus patch?

Mind resending it in a separate thread with all acks added, etc?

Thanks,

	Ingo

Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> > On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> > 
> >>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>
> >> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>
> >> Ben, can you take this in your tree?
> > 
> > Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > 
> > That looks more like generic material. Do we have a kprobes maintainer ?
> > Andrew, do you want to take this ?
> 
> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> Ingo, could you pull this as urgent-for-linus patch?

Mind resending it in a separate thread with all acks added, etc?

Thanks,

	Ingo

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/16 22:28), Ingo Molnar wrote:
> 
> * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> 
>> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
>>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
>>>
>>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>>>
>>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>>>
>>>> Ben, can you take this in your tree?
>>>
>>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>>
>>> That looks more like generic material. Do we have a kprobes maintainer ?
>>> Andrew, do you want to take this ?
>>
>> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
>> Ingo, could you pull this as urgent-for-linus patch?
> 
> Mind resending it in a separate thread with all acks added, etc?

OK, I'll resend that soon.
BTW, I missed Suzuki's Signed-off-by in this version,
I'd like to recover that since he made a big bugfix on this.

Thanks,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/16 22:28), Ingo Molnar wrote:
> 
> * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> 
>> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
>>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
>>>
>>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>>>
>>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>>>
>>>> Ben, can you take this in your tree?
>>>
>>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>>
>>> That looks more like generic material. Do we have a kprobes maintainer ?
>>> Andrew, do you want to take this ?
>>
>> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
>> Ingo, could you pull this as urgent-for-linus patch?
> 
> Mind resending it in a separate thread with all acks added, etc?

OK, I'll resend that soon.
BTW, I missed Suzuki's Signed-off-by in this version,
I'd like to recover that since he made a big bugfix on this.

Thanks,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Masami Hiramatsu]

(2014/07/16 22:28), Ingo Molnar wrote:
> 
> * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> 
>> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
>>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
>>>
>>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
>>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
>>>>> Tested-by: Tony Luck <tony.luck@intel.com>
>>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>>>
>>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
>>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
>>>>
>>>> Ben, can you take this in your tree?
>>>
>>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>>
>>> That looks more like generic material. Do we have a kprobes maintainer ?
>>> Andrew, do you want to take this ?
>>
>> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
>> Ingo, could you pull this as urgent-for-linus patch?
> 
> Mind resending it in a separate thread with all acks added, etc?

OK, I'll resend that soon.
BTW, I missed Suzuki's Signed-off-by in this version,
I'd like to recover that since he made a big bugfix on this.

Thanks,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/16 22:28), Ingo Molnar wrote:
> > 
> > * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> > 
> >> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> >>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> >>>
> >>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>>>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>>>
> >>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>>>
> >>>> Ben, can you take this in your tree?
> >>>
> >>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> >>>
> >>> That looks more like generic material. Do we have a kprobes maintainer ?
> >>> Andrew, do you want to take this ?
> >>
> >> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> >> Ingo, could you pull this as urgent-for-linus patch?
> > 
> > Mind resending it in a separate thread with all acks added, etc?
> 
> OK, I'll resend that soon.
> BTW, I missed Suzuki's Signed-off-by in this version,
> I'd like to recover that since he made a big bugfix on this.

That kind of credit can be added as:

  Fixed-by: Suzuki K. Poulose <suzuki@in.ibm.com>

and by also adding a sentence to the log message (outside of the 
version changelogs which get stripped ususally).

Thanks,

	Ingo

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/16 22:28), Ingo Molnar wrote:
> > 
> > * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> > 
> >> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> >>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> >>>
> >>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>>>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>>>
> >>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>>>
> >>>> Ben, can you take this in your tree?
> >>>
> >>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> >>>
> >>> That looks more like generic material. Do we have a kprobes maintainer ?
> >>> Andrew, do you want to take this ?
> >>
> >> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> >> Ingo, could you pull this as urgent-for-linus patch?
> > 
> > Mind resending it in a separate thread with all acks added, etc?
> 
> OK, I'll resend that soon.
> BTW, I missed Suzuki's Signed-off-by in this version,
> I'd like to recover that since he made a big bugfix on this.

That kind of credit can be added as:

  Fixed-by: Suzuki K. Poulose <suzuki@in.ibm.com>

and by also adding a sentence to the log message (outside of the 
version changelogs which get stripped ususally).

Thanks,

	Ingo

Re: Re: Re: [PATCH v5 2/2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64

[Ingo Molnar]

* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> (2014/07/16 22:28), Ingo Molnar wrote:
> > 
> > * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
> > 
> >> (2014/07/15 16:16), Benjamin Herrenschmidt wrote:
> >>> On Tue, 2014-07-15 at 13:19 +1000, Michael Ellerman wrote:
> >>>
> >>>>> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> >>>>> Reported-by: Tony Luck <tony.luck@gmail.com>
> >>>>> Tested-by: Tony Luck <tony.luck@intel.com>
> >>>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
> >>>>
> >>>> Tested-by: Michael Ellerman <mpe@ellerman.id.au>
> >>>> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
> >>>>
> >>>> Ben, can you take this in your tree?
> >>>
> >>> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> >>>
> >>> That looks more like generic material. Do we have a kprobes maintainer ?
> >>> Andrew, do you want to take this ?
> >>
> >> Yeah, I usually use Ingo's tip tree for kprobes maintenance.
> >> Ingo, could you pull this as urgent-for-linus patch?
> > 
> > Mind resending it in a separate thread with all acks added, etc?
> 
> OK, I'll resend that soon.
> BTW, I missed Suzuki's Signed-off-by in this version,
> I'd like to recover that since he made a big bugfix on this.

That kind of credit can be added as:

  Fixed-by: Suzuki K. Poulose <suzuki@in.ibm.com>

and by also adding a sentence to the log message (outside of the 
version changelogs which get stripped ususally).

Thanks,

	Ingo