From: Peter Zijlstra <peterz@infradead.org>
Date: Wed, 8 May 2019 07:40:54 +0000 (+0200)
Subject: x86/stackframe/32: Allow int3_emulate_push()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=faeedb0679bee39ebffc6d53111e86932dea189a;p=openwrt%2Fstaging%2Fblogic.git

x86/stackframe/32: Allow int3_emulate_push()

Now that x86_32 has an unconditional gap on the kernel stack frame,
the int3_emulate_push() thing will work without further changes.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h
index 880b5515b1d6..ebf185fa30bc 100644
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -51,7 +51,6 @@ static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip)
 #define INT3_INSN_SIZE 1
 #define CALL_INSN_SIZE 5
 
-#ifdef CONFIG_X86_64
 static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val)
 {
 	/*
@@ -69,7 +68,6 @@ static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func)
 	int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE);
 	int3_emulate_jmp(regs, func);
 }
-#endif /* CONFIG_X86_64 */
 #endif /* !CONFIG_UML_X86 */
 
 #endif /* _ASM_X86_TEXT_PATCHING_H */
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 0927bb158ffc..a4eea7bad4a1 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -300,7 +300,6 @@ int ftrace_int3_handler(struct pt_regs *regs)
 
 	ip = regs->ip - INT3_INSN_SIZE;
 
-#ifdef CONFIG_X86_64
 	if (ftrace_location(ip)) {
 		int3_emulate_call(regs, (unsigned long)ftrace_regs_caller);
 		return 1;
@@ -312,12 +311,6 @@ int ftrace_int3_handler(struct pt_regs *regs)
 		int3_emulate_call(regs, ftrace_update_func_call);
 		return 1;
 	}
-#else
-	if (ftrace_location(ip) || is_ftrace_caller(ip)) {
-		int3_emulate_jmp(regs, ip + CALL_INSN_SIZE);
-		return 1;
-	}
-#endif
 
 	return 0;
 }