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authorMasami Hiramatsu <mhiramat@kernel.org>2018-01-13 02:55:03 +0900
committerAlexei Starovoitov <ast@kernel.org>2018-01-12 17:33:38 -0800
commit540adea3809f61115d2a1ea4ed6e627613452ba1 (patch)
tree03ba07d13807d06d52053b2d02565075f210c2e2 /arch
parenttracing/kprobe: bpf: Compare instruction pointer with original one (diff)
downloadlinux-dev-540adea3809f61115d2a1ea4ed6e627613452ba1.tar.xz
linux-dev-540adea3809f61115d2a1ea4ed6e627613452ba1.zip
error-injection: Separate error-injection from kprobe
Since error-injection framework is not limited to be used by kprobes, nor bpf. Other kernel subsystems can use it freely for checking safeness of error-injection, e.g. livepatch, ftrace etc. So this separate error-injection framework from kprobes. Some differences has been made: - "kprobe" word is removed from any APIs/structures. - BPF_ALLOW_ERROR_INJECTION() is renamed to ALLOW_ERROR_INJECTION() since it is not limited for BPF too. - CONFIG_FUNCTION_ERROR_INJECTION is the config item of this feature. It is automatically enabled if the arch supports error injection feature for kprobe or ftrace etc. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to '')
-rw-r--r--arch/Kconfig2
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--arch/x86/include/asm/error-injection.h13
-rw-r--r--arch/x86/kernel/kprobes/core.c14
-rw-r--r--arch/x86/lib/Makefile1
-rw-r--r--arch/x86/lib/error-inject.c19
6 files changed, 35 insertions, 16 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index d3f4aaf9cb7a..97376accfb14 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -196,7 +196,7 @@ config HAVE_OPTPROBES
config HAVE_KPROBES_ON_FTRACE
bool
-config HAVE_KPROBE_OVERRIDE
+config HAVE_FUNCTION_ERROR_INJECTION
bool
config HAVE_NMI
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 45dc6233f2b9..366b19cb79b7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -154,7 +154,7 @@ config X86
select HAVE_KERNEL_XZ
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
- select HAVE_KPROBE_OVERRIDE
+ select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_KRETPROBES
select HAVE_KVM
select HAVE_LIVEPATCH if X86_64
diff --git a/arch/x86/include/asm/error-injection.h b/arch/x86/include/asm/error-injection.h
new file mode 100644
index 000000000000..47b7a1296245
--- /dev/null
+++ b/arch/x86/include/asm/error-injection.h
@@ -0,0 +1,13 @@
+/* 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/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index b02a377d5905..bd36f3c33cd0 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1183,17 +1183,3 @@ int arch_trampoline_kprobe(struct kprobe *p)
{
return 0;
}
-
-asmlinkage void override_func(void);
-asm(
- ".type override_func, @function\n"
- "override_func:\n"
- " ret\n"
- ".size override_func, .-override_func\n"
-);
-
-void arch_kprobe_override_function(struct pt_regs *regs)
-{
- regs->ip = (unsigned long)&override_func;
-}
-NOKPROBE_SYMBOL(arch_kprobe_override_function);
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 7b181b61170e..171377b83be1 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -26,6 +26,7 @@ lib-y += memcpy_$(BITS).o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
+lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
diff --git a/arch/x86/lib/error-inject.c b/arch/x86/lib/error-inject.c
new file mode 100644
index 000000000000..7b881d03d0dd
--- /dev/null
+++ b/arch/x86/lib/error-inject.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+asmlinkage void just_return_func(void);
+
+asm(
+ ".type just_return_func, @function\n"
+ "just_return_func:\n"
+ " ret\n"
+ ".size just_return_func, .-just_return_func\n"
+);
+
+void override_function_with_return(struct pt_regs *regs)
+{
+ regs->ip = (unsigned long)&just_return_func;
+}
+NOKPROBE_SYMBOL(override_function_with_return);