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, pbonzini@redhat.com,
mathieu.desnoyers@efficios.com
Subject: [PATCH v4 13/18] x86/alternatives: Teach text_poke_bp() to emulate RET
Date: Fri, 01 May 2020 22:29:02 +0200 [thread overview]
Message-ID: <20200501202944.536135282@infradead.org> (raw)
In-Reply-To: 20200501202849.647891881@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:
next prev parent reply other threads:[~2020-05-01 20:32 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 20:28 [PATCH v4 00/18] Add static_call() Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 01/18] notifier: Fix broken error handling pattern Peter Zijlstra
2020-05-01 23:35 ` Steven Rostedt
2020-05-01 20:28 ` [PATCH v4 02/18] module: Fix up module_notifier return values Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 03/18] module: Properly propagate MODULE_STATE_COMING failure Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 04/18] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 05/18] compiler.h: Make __ADDRESSABLE() symbol truly unique Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 06/18] static_call: Add basic static call infrastructure Peter Zijlstra
2020-05-05 21:21 ` Josh Poimboeuf
2020-05-01 20:28 ` [PATCH v4 07/18] static_call: Add inline " Peter Zijlstra
2020-05-05 22:10 ` Josh Poimboeuf
2020-05-06 16:15 ` Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 08/18] static_call: Avoid kprobes on inline static_call()s Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 09/18] x86/static_call: Add out-of-line static call implementation Peter Zijlstra
2020-05-06 16:16 ` Peter Zijlstra
2020-05-01 20:28 ` [PATCH v4 10/18] x86/static_call: Add inline static call implementation for x86-64 Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 11/18] static_call: Simple self-test Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 12/18] tracepoint: Optimize using static_call() Peter Zijlstra
2020-05-13 8:48 ` [tracepoint] 01edfaf177: WARNING:at_kernel/static_call.c:#__static_call_update kernel test robot
2020-05-15 17:13 ` Peter Zijlstra
2020-05-01 20:29 ` Peter Zijlstra [this message]
2020-05-01 20:29 ` [PATCH v4 14/18] static_call: Add static_cond_call() Peter Zijlstra
2020-05-02 13:08 ` Rasmus Villemoes
2020-05-03 12:58 ` Peter Zijlstra
2020-05-04 7:20 ` Rasmus Villemoes
2020-05-04 20:14 ` Peter Zijlstra
2020-05-05 7:50 ` Rasmus Villemoes
2020-05-05 9:38 ` Peter Zijlstra
2020-05-05 9:36 ` Peter Zijlstra
2020-05-05 18:13 ` Nick Desaulniers
2020-05-05 18:27 ` Nick Desaulniers
2020-05-05 18:48 ` Linus Torvalds
2020-05-05 19:00 ` Mathieu Desnoyers
2020-05-05 19:57 ` Nick Desaulniers
2020-05-05 20:27 ` Mathieu Desnoyers
2020-05-06 13:55 ` Peter Zijlstra
2020-05-06 14:01 ` Mathieu Desnoyers
2020-05-06 16:18 ` Peter Zijlstra
2020-05-06 13:51 ` Peter Zijlstra
2020-05-06 16:00 ` Peter Zijlstra
2020-05-06 17:16 ` Linus Torvalds
2020-05-06 19:57 ` Andy Lutomirski
2020-05-06 17:24 ` Josh Poimboeuf
2020-05-06 17:58 ` Peter Zijlstra
2020-05-06 18:09 ` Josh Poimboeuf
2020-05-06 18:16 ` Peter Zijlstra
2020-05-08 15:27 ` Peter Zijlstra
2020-05-08 15:47 ` Josh Poimboeuf
2020-05-08 16:17 ` Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 15/18] static_call: Handle tail-calls Peter Zijlstra
2020-05-06 18:10 ` Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 16/18] static_call: Allow early init Peter Zijlstra
2020-05-06 21:15 ` Josh Poimboeuf
2020-05-08 13:31 ` Peter Zijlstra
2020-05-08 14:27 ` Josh Poimboeuf
2020-05-08 15:30 ` Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 17/18] x86/perf, static_call: Optimize x86_pmu methods Peter Zijlstra
2020-05-01 20:29 ` [PATCH v4 18/18] objtool: Clean up elf_write() condition Peter Zijlstra
2020-05-06 17:32 ` [PATCH v4 00/18] Add static_call() Josh Poimboeuf
2020-05-06 18:05 ` Peter Zijlstra
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