All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: peterz@infradead.org, linux-kernel@vger.kernel.org,
	rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com,
	jbaron@akamai.com, torvalds@linux-foundation.org,
	tglx@linutronix.de, mingo@kernel.org, namit@vmware.com,
	hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org,
	jpoimboe@redhat.com
Subject: [RESEND][PATCH v3 13/17] x86/alternatives: Teach text_poke_bp() to emulate RET
Date: Tue, 24 Mar 2020 14:56:16 +0100	[thread overview]
Message-ID: <20200324142246.066152557@infradead.org> (raw)
In-Reply-To: 20200324135603.483964896@infradead.org

Future patches will need to poke a RET instruction, provide the
infrastructure required for this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/text-patching.h |   17 +++++++++++++++++
 arch/x86/kernel/alternative.c        |    5 +++++
 2 files changed, 22 insertions(+)

--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -53,6 +53,9 @@ extern void text_poke_finish(void);
 #define INT3_INSN_SIZE		1
 #define INT3_INSN_OPCODE	0xCC
 
+#define RET_INSN_SIZE		1
+#define RET_INSN_OPCODE		0xC3
+
 #define CALL_INSN_SIZE		5
 #define CALL_INSN_OPCODE	0xE8
 
@@ -73,6 +76,7 @@ static inline int text_opcode_size(u8 op
 
 	switch(opcode) {
 	__CASE(INT3);
+	__CASE(RET);
 	__CASE(CALL);
 	__CASE(JMP32);
 	__CASE(JMP8);
@@ -138,11 +142,24 @@ static inline void int3_emulate_push(str
 	*(unsigned long *)regs->sp = val;
 }
 
+static inline unsigned long int3_emulate_pop(struct pt_regs *regs)
+{
+	unsigned long val = *(unsigned long *)regs->sp;
+	regs->sp += sizeof(unsigned long);
+	return val;
+}
+
 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);
 }
+
+static inline void int3_emulate_ret(struct pt_regs *regs)
+{
+	unsigned long ip = int3_emulate_pop(regs);
+	int3_emulate_jmp(regs, ip);
+}
 #endif /* !CONFIG_UML_X86 */
 
 #endif /* _ASM_X86_TEXT_PATCHING_H */
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1045,6 +1045,10 @@ int notrace poke_int3_handler(struct pt_
 		 */
 		goto out_put;
 
+	case RET_INSN_OPCODE:
+		int3_emulate_ret(regs);
+		break;
+
 	case CALL_INSN_OPCODE:
 		int3_emulate_call(regs, (long)ip + tp->rel32);
 		break;
@@ -1187,6 +1191,7 @@ void text_poke_loc_init(struct text_poke
 
 	switch (tp->opcode) {
 	case INT3_INSN_OPCODE:
+	case RET_INSN_OPCODE:
 		break;
 
 	case CALL_INSN_OPCODE:



  parent reply	other threads:[~2020-03-24 14:25 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-24 13:56 [RESEND][PATCH v3 00/17] Add static_call() Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 01/17] notifier: Fix broken error handling pattern Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 02/17] module: Fix up module_notifier return values Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 03/17] module: Properly propagate MODULE_STATE_COMING failure Peter Zijlstra
2020-03-25 17:35   ` Jessica Yu
2020-03-27  4:51     ` Josh Poimboeuf
2020-03-27 12:04     ` Miroslav Benes
2020-03-24 13:56 ` [RESEND][PATCH v3 04/17] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 05/17] compiler.h: Make __ADDRESSABLE() symbol truly unique Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 06/17] static_call: Add basic static call infrastructure Peter Zijlstra
2020-03-26 16:42   ` Nadav Amit
2020-03-26 17:01     ` Peter Zijlstra
2020-03-26 18:09       ` Nadav Amit
2020-03-26 18:28         ` Peter Zijlstra
2020-03-26 19:02           ` Nadav Amit
2020-03-26 19:13             ` Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 07/17] static_call: Add inline " Peter Zijlstra
2020-03-26 15:54   ` Borislav Petkov
2020-03-24 13:56 ` [RESEND][PATCH v3 08/17] static_call: Avoid kprobes on inline static_call()s Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 09/17] x86/static_call: Add out-of-line static call implementation Peter Zijlstra
2020-03-26 14:57   ` Borislav Petkov
2020-04-06  1:08   ` Fangrui Song
2020-04-06 11:04     ` Peter Zijlstra
2020-04-06 18:29       ` Nick Desaulniers
2020-03-24 13:56 ` [RESEND][PATCH v3 10/17] x86/static_call: Add inline static call implementation for x86-64 Peter Zijlstra
2020-03-26 15:17   ` Borislav Petkov
2020-03-26 16:06   ` Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 11/17] static_call: Simple self-test Peter Zijlstra
2020-03-26 15:44   ` Borislav Petkov
2020-03-26 17:08     ` Peter Zijlstra
2020-03-26 17:33       ` Borislav Petkov
2020-03-24 13:56 ` [RESEND][PATCH v3 12/17] tracepoint: Optimize using static_call() Peter Zijlstra
2020-03-24 13:56 ` Peter Zijlstra [this message]
2020-03-24 13:56 ` [RESEND][PATCH v3 14/17] static_call: Add static_cond_call() Peter Zijlstra
2020-03-24 16:14   ` Linus Torvalds
2020-03-24 16:22     ` Andy Lutomirski
2020-03-24 16:33       ` Linus Torvalds
2020-03-24 17:03         ` Peter Zijlstra
2020-03-25 18:13           ` Peter Zijlstra
2020-03-25 18:26             ` Linus Torvalds
2020-03-25 19:34         ` hpa
2020-03-25 20:52           ` Linus Torvalds
2020-03-25 22:07             ` Peter Zijlstra
2020-03-24 16:54     ` Peter Zijlstra
2020-03-26 23:37   ` Rasmus Villemoes
2020-03-27 10:08     ` Peter Zijlstra
2020-03-27 13:25       ` Rasmus Villemoes
2020-03-24 13:56 ` [RESEND][PATCH v3 15/17] static_call: Handle tail-calls Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 16/17] static_call: Allow early init Peter Zijlstra
2020-03-24 13:56 ` [RESEND][PATCH v3 17/17] x86/perf, static_call: Optimize x86_pmu methods Peter Zijlstra
2020-03-25 17:49 ` [RESEND][PATCH v3 00/17] Add static_call() Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200324142246.066152557@infradead.org \
    --to=peterz@infradead.org \
    --cc=ard.biesheuvel@linaro.org \
    --cc=bristot@redhat.com \
    --cc=hpa@zytor.com \
    --cc=jbaron@akamai.com \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=namit@vmware.com \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.