[PATCH] arm64: ftrace: don't dereference a probably invalid address
From: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Date: 2021-06-07 03:24:43
Also in:
linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), function hooks (ftrace), the rest · Maintainers:
Catalin Marinas, Will Deacon, Steven Rostedt, Masami Hiramatsu, Linus Torvalds
Address in __mcount_loc may be invalid if somthing goes wrong. On our arm64 platform, the bug in recordmcount make kernel crash in ftrace_init(). https://lore.kernel.org/lkml/20210607023839.26387-1-mark-pk.tsai@mediatek.com/ (local) Return -EFAULT if we are dealing with out-of-range condition to prevent dereference the invalid address in ftrace_bug(), then the kernel can disable ftrace safely for problematic __mcount_loc. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> --- arch/arm64/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index b5d3ddaf69d9..98bec8445a58 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c@@ -201,7 +201,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, preempt_enable(); if (WARN_ON(!mod)) - return -EINVAL; + return -EFAULT; } /*
--
2.18.0
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