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
---
Changes in v3:
- Fix a build error for asmlinkage on i386 by including compiler.h
- Fix "CONFIG_FUNCTION_ERROR_INJECT" typo.
- Separate CONFIG_MODULES dependent code
- Add CONFIG_KPROBES dependency for arch_deref_entry_point()
- Call error-injection init function in late_initcall stage.
- Fix read-side mutex lock
- Some cosmetic cleanups
Changes in v4:
- Include error-injection.h for each ALLOW_ERROR_INJECTION
macro user, instead of bpf.h
---
arch/Kconfig |2
arch/x86/Kconfig |2
arch/x86/include/asm/error-injection.h | 13 ++
arch/x86/kernel/kprobes/core.c | 14 --
arch/x86/lib/Makefile |1
arch/x86/lib/error-inject.c| 19 +++
fs/btrfs/disk-io.c |4 -
fs/btrfs/free-space-cache.c|4 -
include/asm-generic/error-injection.h | 20 +++
include/asm-generic/vmlinux.lds.h | 14 +-
include/linux/bpf.h| 11 --
include/linux/error-injection.h| 21 +++
include/linux/kprobes.h|1
include/linux/module.h |6 -
kernel/kprobes.c | 163
kernel/module.c|8 +
kernel/trace/Kconfig |2
kernel/trace/bpf_trace.c |4 -
kernel/trace/trace_kprobe.c|3
lib/Kconfig.debug |4 +
lib/Makefile |1
lib/error-inject.c | 213
22 files changed, 317 insertions(+), 213 deletions(-)
create mode 100644 arch/x86/include/asm/error-injection.h
create mode 100644 arch/x86/lib/error-inject.c
create mode 100644 include/asm-generic/error-injection.h
create mode 100644 include/linux/error-injection.h
create mode 100644 lib/error-inject.c
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 ..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
+#include
+#include
+#include
+
+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-i
