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authorGuo Ren <guoren@linux.alibaba.com>2020-12-17 16:01:45 +0000
committerPalmer Dabbelt <palmerdabbelt@google.com>2021-01-14 15:09:09 -0800
commitee55ff803b383e03d0855661d3416aa1763e54f9 (patch)
tree68784ade3682f8fdec69c72497155dee098fc83d
parent74784081aac8a0f3636965fc230e2d3b7cc123c6 (diff)
riscv: Add support for function error injection
Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error injection"), this patch supports function error injection for riscv. 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. Test log: cd /sys/kernel/debug/fail_function echo sys_clone > inject echo 100 > probability echo 1 > interval ls / [ 313.176875] FAULT_INJECTION: forcing a failure. [ 313.176875] name fail_function, interval 1, probability 100, space 0, times 1 [ 313.184357] CPU: 0 PID: 87 Comm: sh Not tainted 5.8.0-rc5-00007-g6a758cc #117 [ 313.187616] Call Trace: [ 313.189100] [<ffffffe0002036b6>] walk_stackframe+0x0/0xc2 [ 313.191626] [<ffffffe00020395c>] show_stack+0x40/0x4c [ 313.193927] [<ffffffe000556c60>] dump_stack+0x7c/0x96 [ 313.194795] [<ffffffe0005522e8>] should_fail+0x140/0x142 [ 313.195923] [<ffffffe000299ffc>] fei_kprobe_handler+0x2c/0x5a [ 313.197687] [<ffffffe0009e2ec4>] kprobe_breakpoint_handler+0xb4/0x18a [ 313.200054] [<ffffffe00020357e>] do_trap_break+0x36/0xca [ 313.202147] [<ffffffe000201bca>] ret_from_exception+0x0/0xc [ 313.204556] [<ffffffe000201bbc>] ret_from_syscall+0x0/0x2 -sh: can't fork: Invalid argument Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
-rw-r--r--arch/riscv/Kconfig1
-rw-r--r--arch/riscv/include/asm/ptrace.h6
-rw-r--r--arch/riscv/lib/Makefile2
-rw-r--r--arch/riscv/lib/error-inject.c10
4 files changed, 19 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7b5bb48055e7..18d293f84318 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -67,6 +67,7 @@ config RISCV
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS if MMU
select HAVE_EBPF_JIT if MMU
+ select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_GCC_PLUGINS
select HAVE_GENERIC_VDSO if MMU && 64BIT
diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h
index 23372bbcfde8..cb4abb639e8d 100644
--- a/arch/riscv/include/asm/ptrace.h
+++ b/arch/riscv/include/asm/ptrace.h
@@ -109,6 +109,12 @@ static inline unsigned long regs_return_value(struct pt_regs *regs)
return regs->a0;
}
+static inline void regs_set_return_value(struct pt_regs *regs,
+ unsigned long val)
+{
+ regs->a0 = val;
+}
+
extern int regs_query_register_offset(const char *name);
extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
unsigned int n);
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index ac6171e9c19e..25d5c9664e57 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -5,3 +5,5 @@ lib-y += memset.o
lib-y += memmove.o
lib-$(CONFIG_MMU) += uaccess.o
lib-$(CONFIG_64BIT) += tishift.o
+
+obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/arch/riscv/lib/error-inject.c b/arch/riscv/lib/error-inject.c
new file mode 100644
index 000000000000..d667ade2bc41
--- /dev/null
+++ b/arch/riscv/lib/error-inject.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/error-injection.h>
+#include <linux/kprobes.h>
+
+void override_function_with_return(struct pt_regs *regs)
+{
+ instruction_pointer_set(regs, regs->ra);
+}
+NOKPROBE_SYMBOL(override_function_with_return);