arm64: Add support for function error injection

Inspired by the commit 7cd01b08d3 ("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.

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Leo Yan 2019-08-06 18:00:14 +08:00 committed by Will Deacon
parent 45880f7b7b
commit 42d038c4fb
4 changed files with 26 additions and 0 deletions

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@ -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

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@ -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

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@ -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

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@ -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);