6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jiaxun Yang jiaxun.yang@flygoat.com
commit 11ba1728be3edb6928791f4c622f154ebe228ae6 upstream.
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@app.fastma... Signed-off-by: Jiaxun Yang jiaxun.yang@flygoat.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Cc: Salvatore Bonaccorso carnil@debian.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/include/asm/ptrace.h | 2 ++ arch/mips/kernel/ptrace.c | 7 +++++++ include/linux/ptrace.h | 4 ++++ 3 files changed, 13 insertions(+)
--- a/arch/mips/include/asm/ptrace.h +++ b/arch/mips/include/asm/ptrace.h @@ -155,6 +155,8 @@ static inline long regs_return_value(str }
#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); --- 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.. * --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -402,6 +402,10 @@ static inline void user_single_step_repo #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);