On architectures with delay slot, architecture level instruction pointer (or program counter) in pt_regs may differ from where exception was triggered. Introduce exception_ip hook to invoke architecture code and determine actual instruction pointer to the exception. Link: https://lore.kernel.org/lkml/00d1b813-c55f-4365-8d81-d70258e10b16@xxxxxxxxxxxxxxxx/ Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> --- arch/mips/include/asm/ptrace.h | 2 ++ arch/mips/kernel/ptrace.c | 7 +++++++ include/linux/ptrace.h | 4 ++++ 3 files changed, 13 insertions(+) diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h index daf3cf244ea9..701a233583c2 100644 --- a/arch/mips/include/asm/ptrace.h +++ b/arch/mips/include/asm/ptrace.h @@ -154,6 +154,8 @@ static inline long regs_return_value(struct pt_regs *regs) } #define instruction_pointer(regs) ((regs)->cp0_epc) +extern unsigned long exception_ip(struct pt_regs *regs); +#define exception_ip(regs) exception_ip(regs) #define profile_pc(regs) instruction_pointer(regs) extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall); diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index d9df543f7e2c..59288c13b581 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -31,6 +31,7 @@ #include <linux/seccomp.h> #include <linux/ftrace.h> +#include <asm/branch.h> #include <asm/byteorder.h> #include <asm/cpu.h> #include <asm/cpu-info.h> @@ -48,6 +49,12 @@ #define CREATE_TRACE_POINTS #include <trace/events/syscalls.h> +unsigned long exception_ip(struct pt_regs *regs) +{ + return exception_epc(regs); +} +EXPORT_SYMBOL(exception_ip); + /* * Called by kernel/ptrace.c when detaching.. * diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index eaaef3ffec22..90507d4afcd6 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -393,6 +393,10 @@ static inline void user_single_step_report(struct pt_regs *regs) #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) #endif +#ifndef exception_ip +#define exception_ip(x) instruction_pointer(x) +#endif + extern int task_current_syscall(struct task_struct *target, struct syscall_info *info); extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact); -- 2.43.0
