This small patch set is to add support for function error injection;
this can be used to eanble more advanced debugging feature, e.g.
CONFIG_BPF_KPROBE_OVERRIDE.
The patch 01/03 is to consolidate the function definition which can be
suared cross architectures, patches 02,03/03 are used for enabling
function error injection on arm64 and arm architecture respectively.
I tested on arm64 platform Juno-r2 and one of my laptop with x86
architecture with below steps; I don't test for Arm architecture so
only pass compilation.
- Enable kernel configuration:
CONFIG_BPF_KPROBE_OVERRIDE
CONFIG_BTRFS_FS
CONFIG_BPF_EVENTS=y
CONFIG_KPROBES=y
CONFIG_KPROBE_EVENTS=y
CONFIG_BPF_KPROBE_OVERRIDE=y
- Build samples/bpf on with Debian rootFS:
# cd $kernel
# make headers_install
# make samples/bpf/ LLC=llc-7 CLANG=clang-7
- Run the sample tracex7:
# dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
# DEVICE=$(losetup --show -f testfile.img)
# mkfs.btrfs -f $DEVICE
# ./tracex7 testfile.img
[ 1975.211781] BTRFS error (device (efault)): open_ctree failed
mount: /mnt/linux-kernel/linux-cs-dev/samples/bpf/tmpmnt: mount(2) system call failed: Cannot allocate memory.
Changes from v1:
* Consolidated the function definition into asm-generic header (Will);
* Used APIs to access pt_regs elements (Will);
* Fixed typos in the comments (Will).
Leo Yan (3):
error-injection: Consolidate override function definition
arm64: Add support for function error injection
arm: Add support for function error injection
arch/arm/Kconfig | 1 +
arch/arm/include/asm/ptrace.h | 5 +++++
arch/arm/lib/Makefile | 2 ++
arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/ptrace.h | 5 +++++
arch/arm64/lib/Makefile | 2 ++
arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++
arch/powerpc/include/asm/error-injection.h | 13 -------------
arch/x86/include/asm/error-injection.h | 13 -------------
include/asm-generic/error-injection.h | 6 ++++++
include/linux/error-injection.h | 6 +++---
12 files changed, 62 insertions(+), 29 deletions(-)
create mode 100644 arch/arm/lib/error-inject.c
create mode 100644 arch/arm64/lib/error-inject.c
delete mode 100644 arch/powerpc/include/asm/error-injection.h
delete mode 100644 arch/x86/include/asm/error-injection.h
--
2.17.1
The function override_function_with_return() is defined separately for
each architecture and every architecture's definition is almost same
with each other. E.g. x86 and powerpc both define function in its own
asm/error-injection.h header and override_function_with_return() has
the same definition, the only difference is that x86 defines an extra
function just_return_func() but it is specific for x86 and is only used
by x86's override_function_with_return(), so don't need to export this
function.
This patch consolidates override_function_with_return() definition into
asm-generic/error-injection.h header, thus all architectures can use the
common definition. As result, the architecture specific headers are
removed; the include/linux/error-injection.h header also changes to
include asm-generic/error-injection.h header rather than architecture
header, furthermore, it includes linux/compiler.h for successful
compilation.
Signed-off-by: Leo Yan <[email protected]>
---
arch/powerpc/include/asm/error-injection.h | 13 -------------
arch/x86/include/asm/error-injection.h | 13 -------------
include/asm-generic/error-injection.h | 6 ++++++
include/linux/error-injection.h | 6 +++---
4 files changed, 9 insertions(+), 29 deletions(-)
delete mode 100644 arch/powerpc/include/asm/error-injection.h
delete mode 100644 arch/x86/include/asm/error-injection.h
diff --git a/arch/powerpc/include/asm/error-injection.h b/arch/powerpc/include/asm/error-injection.h
deleted file mode 100644
index 62fd24739852..000000000000
--- a/arch/powerpc/include/asm/error-injection.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-
-#ifndef _ASM_ERROR_INJECTION_H
-#define _ASM_ERROR_INJECTION_H
-
-#include <linux/compiler.h>
-#include <linux/linkage.h>
-#include <asm/ptrace.h>
-#include <asm-generic/error-injection.h>
-
-void override_function_with_return(struct pt_regs *regs);
-
-#endif /* _ASM_ERROR_INJECTION_H */
diff --git a/arch/x86/include/asm/error-injection.h b/arch/x86/include/asm/error-injection.h
deleted file mode 100644
index 47b7a1296245..000000000000
--- a/arch/x86/include/asm/error-injection.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_ERROR_INJECTION_H
-#define _ASM_ERROR_INJECTION_H
-
-#include <linux/compiler.h>
-#include <linux/linkage.h>
-#include <asm/ptrace.h>
-#include <asm-generic/error-injection.h>
-
-asmlinkage void just_return_func(void);
-void override_function_with_return(struct pt_regs *regs);
-
-#endif /* _ASM_ERROR_INJECTION_H */
diff --git a/include/asm-generic/error-injection.h b/include/asm-generic/error-injection.h
index 95a159a4137f..80ca61058dd2 100644
--- a/include/asm-generic/error-injection.h
+++ b/include/asm-generic/error-injection.h
@@ -16,6 +16,8 @@ struct error_injection_entry {
int etype;
};
+struct pt_regs;
+
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
/*
* Whitelist ganerating macro. Specify functions which can be
@@ -28,8 +30,12 @@ static struct error_injection_entry __used \
.addr = (unsigned long)fname, \
.etype = EI_ETYPE_##_etype, \
};
+
+void override_function_with_return(struct pt_regs *regs);
#else
#define ALLOW_ERROR_INJECTION(fname, _etype)
+
+static inline void override_function_with_return(struct pt_regs *regs) { }
#endif
#endif
diff --git a/include/linux/error-injection.h b/include/linux/error-injection.h
index 280c61ecbf20..635a95caf29f 100644
--- a/include/linux/error-injection.h
+++ b/include/linux/error-injection.h
@@ -2,16 +2,16 @@
#ifndef _LINUX_ERROR_INJECTION_H
#define _LINUX_ERROR_INJECTION_H
-#ifdef CONFIG_FUNCTION_ERROR_INJECTION
+#include <linux/compiler.h>
+#include <asm-generic/error-injection.h>
-#include <asm/error-injection.h>
+#ifdef CONFIG_FUNCTION_ERROR_INJECTION
extern bool within_error_injection_list(unsigned long addr);
extern int get_injectable_error_type(unsigned long addr);
#else /* !CONFIG_FUNCTION_ERROR_INJECTION */
-#include <asm-generic/error-injection.h>
static inline bool within_error_injection_list(unsigned long addr)
{
return false;
--
2.17.1
Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function
error injection"), this patch supports function error injection for
Arm64.
This patch mainly support two functions: one is regs_set_return_value()
which is used to overwrite the return value; the another function is
override_function_with_return() which is to override the probed
function returning and jump to its caller.
Signed-off-by: Leo Yan <[email protected]>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/ptrace.h | 5 +++++
arch/arm64/lib/Makefile | 2 ++
arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++
4 files changed, 26 insertions(+)
create mode 100644 arch/arm64/lib/error-inject.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3adcec05b1f6..b15803afb2a0 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -148,6 +148,7 @@ config ARM64
select HAVE_FAST_GUP
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_TRACER
+ select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_GCC_PLUGINS
select HAVE_HW_BREAKPOINT if PERF_EVENTS
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index b1dd039023ef..891b9995cb4b 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -301,6 +301,11 @@ static inline unsigned long regs_return_value(struct pt_regs *regs)
return regs->regs[0];
}
+static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
+{
+ regs->regs[0] = rc;
+}
+
/**
* regs_get_kernel_argument() - get Nth function argument in kernel
* @regs: pt_regs of that context
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 33c2a4abda04..f182ccb0438e 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -33,3 +33,5 @@ UBSAN_SANITIZE_atomic_ll_sc.o := n
lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
obj-$(CONFIG_CRC32) += crc32.o
+
+obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/arm64/lib/error-inject.c b/arch/arm64/lib/error-inject.c
new file mode 100644
index 000000000000..ed15021da3ed
--- /dev/null
+++ b/arch/arm64/lib/error-inject.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+void override_function_with_return(struct pt_regs *regs)
+{
+ /*
+ * 'regs' represents the state on entry of a predefined function in
+ * the kernel/module and which is captured on a kprobe.
+ *
+ * When kprobe returns back from exception it will override the end
+ * of probed function and directly return to the predefined
+ * function's caller.
+ */
+ instruction_pointer_set(regs, procedure_link_pointer(regs));
+}
+NOKPROBE_SYMBOL(override_function_with_return);
--
2.17.1
This patch implements arm specific functions regs_set_return_value() and
override_function_with_return() to support function error injection.
In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr
so can override the probed function return.
Signed-off-by: Leo Yan <[email protected]>
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/ptrace.h | 5 +++++
arch/arm/lib/Makefile | 2 ++
arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
4 files changed, 27 insertions(+)
create mode 100644 arch/arm/lib/error-inject.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 33b00579beff..2d3d44a037f6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -77,6 +77,7 @@ config ARM
select HAVE_EXIT_THREAD
select HAVE_FAST_GUP if ARM_LPAE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
+ select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
select HAVE_FUNCTION_TRACER if !XIP_KERNEL
select HAVE_GCC_PLUGINS
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 91d6b7856be4..3b41f37b361a 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs)
return regs->ARM_r0;
}
+static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
+{
+ regs->ARM_r0 = rc;
+}
+
#define instruction_pointer(regs) (regs)->ARM_pc
#ifdef CONFIG_THUMB2_KERNEL
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index b25c54585048..8f56484a7156 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
CFLAGS_xor-neon.o += $(NEON_FLAGS)
obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
endif
+
+obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c
new file mode 100644
index 000000000000..2d696dc94893
--- /dev/null
+++ b/arch/arm/lib/error-inject.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+void override_function_with_return(struct pt_regs *regs)
+{
+ /*
+ * 'regs' represents the state on entry of a predefined function in
+ * the kernel/module and which is captured on a kprobe.
+ *
+ * 'regs->ARM_lr' contains the the link register for the probed
+ * function, when kprobe returns back from exception it will override
+ * the end of probed function and directly return to the predefined
+ * function's caller.
+ */
+ instruction_pointer_set(regs, regs->ARM_lr);
+}
+NOKPROBE_SYMBOL(override_function_with_return);
--
2.17.1
On Tue, 6 Aug 2019 18:00:12 +0800
Leo Yan <[email protected]> wrote:
> This small patch set is to add support for function error injection;
> this can be used to eanble more advanced debugging feature, e.g.
> CONFIG_BPF_KPROBE_OVERRIDE.
>
> The patch 01/03 is to consolidate the function definition which can be
> suared cross architectures, patches 02,03/03 are used for enabling
> function error injection on arm64 and arm architecture respectively.
>
> I tested on arm64 platform Juno-r2 and one of my laptop with x86
> architecture with below steps; I don't test for Arm architecture so
> only pass compilation.
>
> - Enable kernel configuration:
> CONFIG_BPF_KPROBE_OVERRIDE
> CONFIG_BTRFS_FS
> CONFIG_BPF_EVENTS=y
> CONFIG_KPROBES=y
> CONFIG_KPROBE_EVENTS=y
> CONFIG_BPF_KPROBE_OVERRIDE=y
>
> - Build samples/bpf on with Debian rootFS:
> # cd $kernel
> # make headers_install
> # make samples/bpf/ LLC=llc-7 CLANG=clang-7
>
> - Run the sample tracex7:
> # dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
> # DEVICE=$(losetup --show -f testfile.img)
> # mkfs.btrfs -f $DEVICE
> # ./tracex7 testfile.img
> [ 1975.211781] BTRFS error (device (efault)): open_ctree failed
> mount: /mnt/linux-kernel/linux-cs-dev/samples/bpf/tmpmnt: mount(2) system call failed: Cannot allocate memory.
>
> Changes from v1:
> * Consolidated the function definition into asm-generic header (Will);
> * Used APIs to access pt_regs elements (Will);
> * Fixed typos in the comments (Will).
This looks good to me.
Reviewed-by: Masami Hiramatsu <[email protected]>
Thank you!
>
>
> Leo Yan (3):
> error-injection: Consolidate override function definition
> arm64: Add support for function error injection
> arm: Add support for function error injection
>
> arch/arm/Kconfig | 1 +
> arch/arm/include/asm/ptrace.h | 5 +++++
> arch/arm/lib/Makefile | 2 ++
> arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/ptrace.h | 5 +++++
> arch/arm64/lib/Makefile | 2 ++
> arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++
> arch/powerpc/include/asm/error-injection.h | 13 -------------
> arch/x86/include/asm/error-injection.h | 13 -------------
> include/asm-generic/error-injection.h | 6 ++++++
> include/linux/error-injection.h | 6 +++---
> 12 files changed, 62 insertions(+), 29 deletions(-)
> create mode 100644 arch/arm/lib/error-inject.c
> create mode 100644 arch/arm64/lib/error-inject.c
> delete mode 100644 arch/powerpc/include/asm/error-injection.h
> delete mode 100644 arch/x86/include/asm/error-injection.h
>
> --
> 2.17.1
>
--
Masami Hiramatsu <[email protected]>
On Wed, Aug 07, 2019 at 09:08:11AM +0900, Masami Hiramatsu wrote:
> On Tue, 6 Aug 2019 18:00:12 +0800
> Leo Yan <[email protected]> wrote:
>
> > This small patch set is to add support for function error injection;
> > this can be used to eanble more advanced debugging feature, e.g.
> > CONFIG_BPF_KPROBE_OVERRIDE.
> >
> > The patch 01/03 is to consolidate the function definition which can be
> > suared cross architectures, patches 02,03/03 are used for enabling
> > function error injection on arm64 and arm architecture respectively.
> >
> > I tested on arm64 platform Juno-r2 and one of my laptop with x86
> > architecture with below steps; I don't test for Arm architecture so
> > only pass compilation.
> >
> > - Enable kernel configuration:
> > CONFIG_BPF_KPROBE_OVERRIDE
> > CONFIG_BTRFS_FS
> > CONFIG_BPF_EVENTS=y
> > CONFIG_KPROBES=y
> > CONFIG_KPROBE_EVENTS=y
> > CONFIG_BPF_KPROBE_OVERRIDE=y
> >
> > - Build samples/bpf on with Debian rootFS:
> > # cd $kernel
> > # make headers_install
> > # make samples/bpf/ LLC=llc-7 CLANG=clang-7
> >
> > - Run the sample tracex7:
> > # dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
> > # DEVICE=$(losetup --show -f testfile.img)
> > # mkfs.btrfs -f $DEVICE
> > # ./tracex7 testfile.img
> > [ 1975.211781] BTRFS error (device (efault)): open_ctree failed
> > mount: /mnt/linux-kernel/linux-cs-dev/samples/bpf/tmpmnt: mount(2) system call failed: Cannot allocate memory.
> >
> > Changes from v1:
> > * Consolidated the function definition into asm-generic header (Will);
> > * Used APIs to access pt_regs elements (Will);
> > * Fixed typos in the comments (Will).
>
> This looks good to me.
>
> Reviewed-by: Masami Hiramatsu <[email protected]>
>
> Thank you!
Thanks a lot for reviewing, Masami.
Leo.
On Tue, Aug 06, 2019 at 06:00:12PM +0800, Leo Yan wrote:
> This small patch set is to add support for function error injection;
> this can be used to eanble more advanced debugging feature, e.g.
> CONFIG_BPF_KPROBE_OVERRIDE.
>
> The patch 01/03 is to consolidate the function definition which can be
> suared cross architectures, patches 02,03/03 are used for enabling
> function error injection on arm64 and arm architecture respectively.
>
> I tested on arm64 platform Juno-r2 and one of my laptop with x86
> architecture with below steps; I don't test for Arm architecture so
> only pass compilation.
Thanks. I've queued the first two patches up here:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/error-injection
Will
On Wed, Aug 07, 2019 at 05:07:03PM +0100, Will Deacon wrote:
> On Tue, Aug 06, 2019 at 06:00:12PM +0800, Leo Yan wrote:
> > This small patch set is to add support for function error injection;
> > this can be used to eanble more advanced debugging feature, e.g.
> > CONFIG_BPF_KPROBE_OVERRIDE.
> >
> > The patch 01/03 is to consolidate the function definition which can be
> > suared cross architectures, patches 02,03/03 are used for enabling
> > function error injection on arm64 and arm architecture respectively.
> >
> > I tested on arm64 platform Juno-r2 and one of my laptop with x86
> > architecture with below steps; I don't test for Arm architecture so
> > only pass compilation.
>
> Thanks. I've queued the first two patches up here:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/error-injection
Thank you, Will.
Leo.
Hi Russell,
On Tue, Aug 06, 2019 at 06:00:15PM +0800, Leo Yan wrote:
> This patch implements arm specific functions regs_set_return_value() and
> override_function_with_return() to support function error injection.
>
> In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr
> so can override the probed function return.
Gentle ping ... Could you review this patch?
Thanks,
Leo.
> Signed-off-by: Leo Yan <[email protected]>
> ---
> arch/arm/Kconfig | 1 +
> arch/arm/include/asm/ptrace.h | 5 +++++
> arch/arm/lib/Makefile | 2 ++
> arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
> 4 files changed, 27 insertions(+)
> create mode 100644 arch/arm/lib/error-inject.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 33b00579beff..2d3d44a037f6 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -77,6 +77,7 @@ config ARM
> select HAVE_EXIT_THREAD
> select HAVE_FAST_GUP if ARM_LPAE
> select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
> + select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL
> select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
> select HAVE_FUNCTION_TRACER if !XIP_KERNEL
> select HAVE_GCC_PLUGINS
> diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
> index 91d6b7856be4..3b41f37b361a 100644
> --- a/arch/arm/include/asm/ptrace.h
> +++ b/arch/arm/include/asm/ptrace.h
> @@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs)
> return regs->ARM_r0;
> }
>
> +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
> +{
> + regs->ARM_r0 = rc;
> +}
> +
> #define instruction_pointer(regs) (regs)->ARM_pc
>
> #ifdef CONFIG_THUMB2_KERNEL
> diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> index b25c54585048..8f56484a7156 100644
> --- a/arch/arm/lib/Makefile
> +++ b/arch/arm/lib/Makefile
> @@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
> CFLAGS_xor-neon.o += $(NEON_FLAGS)
> obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
> endif
> +
> +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
> diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c
> new file mode 100644
> index 000000000000..2d696dc94893
> --- /dev/null
> +++ b/arch/arm/lib/error-inject.c
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/error-injection.h>
> +#include <linux/kprobes.h>
> +
> +void override_function_with_return(struct pt_regs *regs)
> +{
> + /*
> + * 'regs' represents the state on entry of a predefined function in
> + * the kernel/module and which is captured on a kprobe.
> + *
> + * 'regs->ARM_lr' contains the the link register for the probed
> + * function, when kprobe returns back from exception it will override
> + * the end of probed function and directly return to the predefined
> + * function's caller.
> + */
> + instruction_pointer_set(regs, regs->ARM_lr);
> +}
> +NOKPROBE_SYMBOL(override_function_with_return);
> --
> 2.17.1
>
I'm sorry, I can't apply this, it produces loads of:
include/linux/error-injection.h:7:10: fatal error: asm/error-injection.h: No such file or directory
Since your patch 1 has been merged by the ARM64 people, I can't take
it until next cycle.
On Mon, Aug 19, 2019 at 05:18:08PM +0800, Leo Yan wrote:
> Hi Russell,
>
> On Tue, Aug 06, 2019 at 06:00:15PM +0800, Leo Yan wrote:
> > This patch implements arm specific functions regs_set_return_value() and
> > override_function_with_return() to support function error injection.
> >
> > In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr
> > so can override the probed function return.
>
> Gentle ping ... Could you review this patch?
>
> Thanks,
> Leo.
>
> > Signed-off-by: Leo Yan <[email protected]>
> > ---
> > arch/arm/Kconfig | 1 +
> > arch/arm/include/asm/ptrace.h | 5 +++++
> > arch/arm/lib/Makefile | 2 ++
> > arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
> > 4 files changed, 27 insertions(+)
> > create mode 100644 arch/arm/lib/error-inject.c
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 33b00579beff..2d3d44a037f6 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -77,6 +77,7 @@ config ARM
> > select HAVE_EXIT_THREAD
> > select HAVE_FAST_GUP if ARM_LPAE
> > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
> > + select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL
> > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
> > select HAVE_FUNCTION_TRACER if !XIP_KERNEL
> > select HAVE_GCC_PLUGINS
> > diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
> > index 91d6b7856be4..3b41f37b361a 100644
> > --- a/arch/arm/include/asm/ptrace.h
> > +++ b/arch/arm/include/asm/ptrace.h
> > @@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs)
> > return regs->ARM_r0;
> > }
> >
> > +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
> > +{
> > + regs->ARM_r0 = rc;
> > +}
> > +
> > #define instruction_pointer(regs) (regs)->ARM_pc
> >
> > #ifdef CONFIG_THUMB2_KERNEL
> > diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> > index b25c54585048..8f56484a7156 100644
> > --- a/arch/arm/lib/Makefile
> > +++ b/arch/arm/lib/Makefile
> > @@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
> > CFLAGS_xor-neon.o += $(NEON_FLAGS)
> > obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
> > endif
> > +
> > +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
> > diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c
> > new file mode 100644
> > index 000000000000..2d696dc94893
> > --- /dev/null
> > +++ b/arch/arm/lib/error-inject.c
> > @@ -0,0 +1,19 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +#include <linux/error-injection.h>
> > +#include <linux/kprobes.h>
> > +
> > +void override_function_with_return(struct pt_regs *regs)
> > +{
> > + /*
> > + * 'regs' represents the state on entry of a predefined function in
> > + * the kernel/module and which is captured on a kprobe.
> > + *
> > + * 'regs->ARM_lr' contains the the link register for the probed
> > + * function, when kprobe returns back from exception it will override
> > + * the end of probed function and directly return to the predefined
> > + * function's caller.
> > + */
> > + instruction_pointer_set(regs, regs->ARM_lr);
> > +}
> > +NOKPROBE_SYMBOL(override_function_with_return);
> > --
> > 2.17.1
> >
>
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up
Hi Russell,
On Thu, Aug 29, 2019 at 07:57:29AM +0100, Russell King - ARM Linux admin wrote:
> I'm sorry, I can't apply this, it produces loads of:
>
> include/linux/error-injection.h:7:10: fatal error: asm/error-injection.h: No such file or directory
>
> Since your patch 1 has been merged by the ARM64 people, I can't take
> it until next cycle.
For this case, do you want me to resend this patch in next merge
window? Or you have picked up this patch but will send PR in next
cycle?
Thanks,
Leo Yan
> On Mon, Aug 19, 2019 at 05:18:08PM +0800, Leo Yan wrote:
> > Hi Russell,
> >
> > On Tue, Aug 06, 2019 at 06:00:15PM +0800, Leo Yan wrote:
> > > This patch implements arm specific functions regs_set_return_value() and
> > > override_function_with_return() to support function error injection.
> > >
> > > In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr
> > > so can override the probed function return.
> >
> > Gentle ping ... Could you review this patch?
> >
> > Thanks,
> > Leo.
> >
> > > Signed-off-by: Leo Yan <[email protected]>
> > > ---
> > > arch/arm/Kconfig | 1 +
> > > arch/arm/include/asm/ptrace.h | 5 +++++
> > > arch/arm/lib/Makefile | 2 ++
> > > arch/arm/lib/error-inject.c | 19 +++++++++++++++++++
> > > 4 files changed, 27 insertions(+)
> > > create mode 100644 arch/arm/lib/error-inject.c
> > >
> > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > > index 33b00579beff..2d3d44a037f6 100644
> > > --- a/arch/arm/Kconfig
> > > +++ b/arch/arm/Kconfig
> > > @@ -77,6 +77,7 @@ config ARM
> > > select HAVE_EXIT_THREAD
> > > select HAVE_FAST_GUP if ARM_LPAE
> > > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
> > > + select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL
> > > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
> > > select HAVE_FUNCTION_TRACER if !XIP_KERNEL
> > > select HAVE_GCC_PLUGINS
> > > diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
> > > index 91d6b7856be4..3b41f37b361a 100644
> > > --- a/arch/arm/include/asm/ptrace.h
> > > +++ b/arch/arm/include/asm/ptrace.h
> > > @@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs)
> > > return regs->ARM_r0;
> > > }
> > >
> > > +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
> > > +{
> > > + regs->ARM_r0 = rc;
> > > +}
> > > +
> > > #define instruction_pointer(regs) (regs)->ARM_pc
> > >
> > > #ifdef CONFIG_THUMB2_KERNEL
> > > diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> > > index b25c54585048..8f56484a7156 100644
> > > --- a/arch/arm/lib/Makefile
> > > +++ b/arch/arm/lib/Makefile
> > > @@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
> > > CFLAGS_xor-neon.o += $(NEON_FLAGS)
> > > obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
> > > endif
> > > +
> > > +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
> > > diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c
> > > new file mode 100644
> > > index 000000000000..2d696dc94893
> > > --- /dev/null
> > > +++ b/arch/arm/lib/error-inject.c
> > > @@ -0,0 +1,19 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +#include <linux/error-injection.h>
> > > +#include <linux/kprobes.h>
> > > +
> > > +void override_function_with_return(struct pt_regs *regs)
> > > +{
> > > + /*
> > > + * 'regs' represents the state on entry of a predefined function in
> > > + * the kernel/module and which is captured on a kprobe.
> > > + *
> > > + * 'regs->ARM_lr' contains the the link register for the probed
> > > + * function, when kprobe returns back from exception it will override
> > > + * the end of probed function and directly return to the predefined
> > > + * function's caller.
> > > + */
> > > + instruction_pointer_set(regs, regs->ARM_lr);
> > > +}
> > > +NOKPROBE_SYMBOL(override_function_with_return);
> > > --
> > > 2.17.1
> > >
> >
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
> According to speedtest.net: 11.9Mbps down 500kbps up