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-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/ptrace.h5
-rw-r--r--arch/arm64/lib/Makefile2
-rw-r--r--arch/arm64/lib/error-inject.c18
4 files changed, 26 insertions, 0 deletions
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 1dcf63a9ac1f..fbebb411ae20 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);