Re: [RFC][PATCH][v2] Enable livepatching for powerpc

2016-03-03 Thread Kamalesh Babulal 
* Balbir Singh  [2016-03-03 18:00:54]:

> Changelog:
>   1. Implement review comments by Michael
>   2. The previous version compared _NIP from the
>  wrong location to check for whether we
>  are going to a patched location
> 
> This applies on top of the patches posted by Michael 
> https://patchwork.ozlabs.org/patch/589791/
> 
> It enables livepatching. This takes patch 6/8 and 7/8 of v8 as the base.
> Removes the extra strict check in gcc-profile-kernel-notrace.sh
> and adds logic for checking offsets in livepatch. The patch
> for HAVE_C_RECORDMCOUNT is not required and not used here.
> 
> Depending on whether or not a TOC is generated, the offset
> for _mcount can be +16,+12,+8,+4. The changes are such that the
> offset checks are specific to powerpc.
> 
> TODOs
> 1. Build a version with offsets removed and rebuild
>ftrace_location() sort of functionality
> 2. Make livepatching experimental on powerpc
> 
> Comments? Testing? I tested the sample in the livepatch
> directory
> 
> References
> 
> 1. https://patchwork.ozlabs.org/patch/581521/
> 2. https://patchwork.ozlabs.org/patch/587464/
> 
> Signed-off-by: Torsten Duwe 
> Signed-off-by: Balbir Singh 

Tested-by: Kamalesh Babulal

Re: [RFC][PATCH][v2] Enable livepatching for powerpc

2016-03-03 Thread Kamalesh Babulal 
* Balbir Singh  [2016-03-03 18:00:54]:

> Changelog:
>   1. Implement review comments by Michael
>   2. The previous version compared _NIP from the
>  wrong location to check for whether we
>  are going to a patched location
> 
> This applies on top of the patches posted by Michael 
> https://patchwork.ozlabs.org/patch/589791/
> 
> It enables livepatching. This takes patch 6/8 and 7/8 of v8 as the base.
> Removes the extra strict check in gcc-profile-kernel-notrace.sh
> and adds logic for checking offsets in livepatch. The patch
> for HAVE_C_RECORDMCOUNT is not required and not used here.
> 
> Depending on whether or not a TOC is generated, the offset
> for _mcount can be +16,+12,+8,+4. The changes are such that the
> offset checks are specific to powerpc.
> 
> TODOs
> 1. Build a version with offsets removed and rebuild
>ftrace_location() sort of functionality
> 2. Make livepatching experimental on powerpc
> 
> Comments? Testing? I tested the sample in the livepatch
> directory
> 
> References
> 
> 1. https://patchwork.ozlabs.org/patch/581521/
> 2. https://patchwork.ozlabs.org/patch/587464/
> 
> Signed-off-by: Torsten Duwe 
> Signed-off-by: Balbir Singh 

Tested-by: Kamalesh Babulal

[RFC][PATCH][v2] Enable livepatching for powerpc

2016-03-02 Thread Balbir Singh 
Changelog:
1. Implement review comments by Michael
2. The previous version compared _NIP from the
   wrong location to check for whether we
   are going to a patched location

This applies on top of the patches posted by Michael 
https://patchwork.ozlabs.org/patch/589791/

It enables livepatching. This takes patch 6/8 and 7/8 of v8 as the base.
Removes the extra strict check in gcc-profile-kernel-notrace.sh
and adds logic for checking offsets in livepatch. The patch
for HAVE_C_RECORDMCOUNT is not required and not used here.

Depending on whether or not a TOC is generated, the offset
for _mcount can be +16,+12,+8,+4. The changes are such that the
offset checks are specific to powerpc.

TODOs
1. Build a version with offsets removed and rebuild
   ftrace_location() sort of functionality
2. Make livepatching experimental on powerpc

Comments? Testing? I tested the sample in the livepatch
directory

References

1. https://patchwork.ozlabs.org/patch/581521/
2. https://patchwork.ozlabs.org/patch/587464/

Signed-off-by: Torsten Duwe 
Signed-off-by: Balbir Singh 
---
 arch/powerpc/Kconfig |  3 ++
 arch/powerpc/include/asm/livepatch.h | 41 +++
 arch/powerpc/kernel/Makefile |  1 +
 arch/powerpc/kernel/entry_64.S   | 50 +
 arch/powerpc/kernel/kgdb.c   |  4 +++
 arch/powerpc/kernel/livepatch.c  | 54 
 include/linux/livepatch.h|  2 ++
 kernel/livepatch/core.c  | 12 ++--
 8 files changed, 164 insertions(+), 3 deletions(-)
 create mode 100644 arch/powerpc/include/asm/livepatch.h
 create mode 100644 arch/powerpc/kernel/livepatch.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 792e169..8278e5e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -159,6 +159,7 @@ config PPC
select ARCH_HAS_DEVMEM_IS_ALLOWED
select HAVE_ARCH_SECCOMP_FILTER
select ARCH_HAS_UBSAN_SANITIZE_ALL
+   select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
 
 config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
@@ -1109,3 +1110,5 @@ config PPC_LIB_RHEAP
bool
 
 source "arch/powerpc/kvm/Kconfig"
+
+source "kernel/livepatch/Kconfig"
diff --git a/arch/powerpc/include/asm/livepatch.h 
b/arch/powerpc/include/asm/livepatch.h
new file mode 100644
index 000..9ecd879
--- /dev/null
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -0,0 +1,41 @@
+/*
+ * livepatch.h - powerpc-specific Kernel Live Patching Core
+ *
+ * Copyright (C) 2015 SUSE
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see .
+ */
+#ifndef _ASM_POWERPC64_LIVEPATCH_H
+#define _ASM_POWERPC64_LIVEPATCH_H
+
+#include 
+#include 
+
+#ifdef CONFIG_LIVEPATCH
+
+static inline int klp_check_compiler_support(void)
+{
+   return 0;
+}
+
+extern int klp_write_module_reloc(struct module *mod, unsigned long type,
+  unsigned long loc, unsigned long value);
+
+static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+   regs->nip = ip;
+}
+
+#endif /* CONFIG_LIVEPATCH */
+#endif /* _ASM_POWERPC64_LIVEPATCH_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2da380f..b767e14 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_DYNAMIC_FTRACE)+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)+= ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
 obj-$(CONFIG_TRACING)  += trace_clock.o
+obj-$(CONFIG_LIVEPATCH)+= livepatch.o
 
 ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y  += iomap.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index ec7f8aa..2d5333c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1224,6 +1224,9 @@ _GLOBAL(ftrace_caller)
addir3,r3,function_trace_op@toc@l
ld  r5,0(r3)
 
+#ifdef CONFIG_LIVEPATCH
+   mr  r14,r7  /* remember old NIP */
+#endif
/* Calculate ip from nip-4 into r3 for call below */
subir3, r7, MCOUNT_INSN_SIZE
 
@@ -1248,6 +1251,9 @@ ftrace_call:
/* Load ctr with the possibly modified NIP */
ld  r3, _NIP(r1)
mtctr   r3
+#ifdef

[RFC][PATCH][v2] Enable livepatching for powerpc

2016-03-02 Thread Balbir Singh 
Changelog:
1. Implement review comments by Michael
2. The previous version compared _NIP from the
   wrong location to check for whether we
   are going to a patched location

This applies on top of the patches posted by Michael 
https://patchwork.ozlabs.org/patch/589791/

It enables livepatching. This takes patch 6/8 and 7/8 of v8 as the base.
Removes the extra strict check in gcc-profile-kernel-notrace.sh
and adds logic for checking offsets in livepatch. The patch
for HAVE_C_RECORDMCOUNT is not required and not used here.

Depending on whether or not a TOC is generated, the offset
for _mcount can be +16,+12,+8,+4. The changes are such that the
offset checks are specific to powerpc.

TODOs
1. Build a version with offsets removed and rebuild
   ftrace_location() sort of functionality
2. Make livepatching experimental on powerpc

Comments? Testing? I tested the sample in the livepatch
directory

References

1. https://patchwork.ozlabs.org/patch/581521/
2. https://patchwork.ozlabs.org/patch/587464/

Signed-off-by: Torsten Duwe 
Signed-off-by: Balbir Singh 
---
 arch/powerpc/Kconfig |  3 ++
 arch/powerpc/include/asm/livepatch.h | 41 +++
 arch/powerpc/kernel/Makefile |  1 +
 arch/powerpc/kernel/entry_64.S   | 50 +
 arch/powerpc/kernel/kgdb.c   |  4 +++
 arch/powerpc/kernel/livepatch.c  | 54 
 include/linux/livepatch.h|  2 ++
 kernel/livepatch/core.c  | 12 ++--
 8 files changed, 164 insertions(+), 3 deletions(-)
 create mode 100644 arch/powerpc/include/asm/livepatch.h
 create mode 100644 arch/powerpc/kernel/livepatch.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 792e169..8278e5e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -159,6 +159,7 @@ config PPC
select ARCH_HAS_DEVMEM_IS_ALLOWED
select HAVE_ARCH_SECCOMP_FILTER
select ARCH_HAS_UBSAN_SANITIZE_ALL
+   select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
 
 config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
@@ -1109,3 +1110,5 @@ config PPC_LIB_RHEAP
bool
 
 source "arch/powerpc/kvm/Kconfig"
+
+source "kernel/livepatch/Kconfig"
diff --git a/arch/powerpc/include/asm/livepatch.h 
b/arch/powerpc/include/asm/livepatch.h
new file mode 100644
index 000..9ecd879
--- /dev/null
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -0,0 +1,41 @@
+/*
+ * livepatch.h - powerpc-specific Kernel Live Patching Core
+ *
+ * Copyright (C) 2015 SUSE
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see .
+ */
+#ifndef _ASM_POWERPC64_LIVEPATCH_H
+#define _ASM_POWERPC64_LIVEPATCH_H
+
+#include 
+#include 
+
+#ifdef CONFIG_LIVEPATCH
+
+static inline int klp_check_compiler_support(void)
+{
+   return 0;
+}
+
+extern int klp_write_module_reloc(struct module *mod, unsigned long type,
+  unsigned long loc, unsigned long value);
+
+static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+   regs->nip = ip;
+}
+
+#endif /* CONFIG_LIVEPATCH */
+#endif /* _ASM_POWERPC64_LIVEPATCH_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2da380f..b767e14 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_DYNAMIC_FTRACE)+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)+= ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
 obj-$(CONFIG_TRACING)  += trace_clock.o
+obj-$(CONFIG_LIVEPATCH)+= livepatch.o
 
 ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y  += iomap.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index ec7f8aa..2d5333c 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1224,6 +1224,9 @@ _GLOBAL(ftrace_caller)
addir3,r3,function_trace_op@toc@l
ld  r5,0(r3)
 
+#ifdef CONFIG_LIVEPATCH
+   mr  r14,r7  /* remember old NIP */
+#endif
/* Calculate ip from nip-4 into r3 for call below */
subir3, r7, MCOUNT_INSN_SIZE
 
@@ -1248,6 +1251,9 @@ ftrace_call:
/* Load ctr with the possibly modified NIP */
ld  r3, _NIP(r1)
mtctr   r3
+#ifdef CONFIG_LIVEPATCH
+   cmpdr14,r3