From c608906165355089a4de3c9133c72e81e011096c Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 24 Nov 2017 23:54:22 +0000 Subject: ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code Avoid adding kprobes to any of the kernel entry/exit or startup assembly code, or code in the identity-mapped region. This code does not conform to the standard C conventions, which means that the expectations of the kprobes code is not forfilled. Placing kprobes at some of these locations results in the kernel trying to return to userspace addresses while retaining the CPU in kernel mode. Tested-by: Naresh Kamboju Signed-off-by: Russell King --- arch/arm/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel/traps.c') diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 5cf04888c581..e344bdd2e5ac 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -72,7 +72,7 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); #endif - if (in_exception_text(where)) + if (in_entry_text(from)) dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); } @@ -433,7 +433,7 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr) return fn ? fn(regs, instr) : 1; } -asmlinkage void __exception do_undefinstr(struct pt_regs *regs) +asmlinkage void do_undefinstr(struct pt_regs *regs) { unsigned int instr; siginfo_t info; -- cgit v1.2.1