Patch "ptrace: Introduce exception_ip arch hook" has been added to the 6.7-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ptrace: Introduce exception_ip arch hook

to the 6.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ptrace-introduce-exception_ip-arch-hook.patch
and it can be found in the queue-6.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 084b23b3367c7bcfc1e89c51abb708f48c65a10c
Author: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Date:   Fri Feb 2 12:30:26 2024 +0000

    ptrace: Introduce exception_ip arch hook
    
    [ Upstream commit 11ba1728be3edb6928791f4c622f154ebe228ae6 ]
    
    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>
    Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
    Stable-dep-of: 8fa507083388 ("mm/memory: Use exception ip to search exception tables")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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);