linux-kernel - [PATCH 06/15] x86_32: Allow int3_emulate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190605131944.888069781@infradead.org>
Date:   Wed, 05 Jun 2019 15:07:59 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     x86@...nel.org
Cc:     linux-kernel@...r.kernel.org,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Andy Lutomirski <luto@...nel.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Jason Baron <jbaron@...mai.com>, Jiri Kosina <jkosina@...e.cz>,
        David Laight <David.Laight@...LAB.COM>,
        Borislav Petkov <bp@...en8.de>,
        Julia Cartwright <julia@...com>, Jessica Yu <jeyu@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>, Nadav Amit <namit@...are.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Edward Cree <ecree@...arflare.com>,
        Daniel Bristot de Oliveira <bristot@...hat.com>
Subject: [PATCH 06/15] x86_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@...radead.org>
---
 arch/x86/include/asm/text-patching.h |    2 --
 arch/x86/kernel/ftrace.c             |    7 -------
 2 files changed, 9 deletions(-)

--- 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(stru
 #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(str
 	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 */
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -300,7 +300,6 @@ int ftrace_int3_handler(struct pt_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 *
 		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;
 }