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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, jeyu@kernel.org,
	alexei.starovoitov@gmail.com
Subject: [PATCH -v5 09/17] x86/alternative: Remove text_poke_loc::len
Date: Mon, 11 Nov 2019 14:13:01 +0100	[thread overview]
Message-ID: <20191111132457.989922744@infradead.org> (raw)
In-Reply-To: 20191111131252.921588318@infradead.org

Per the BUG_ON(len != insn.length) in text_poke_loc_init(), tp->len
must indeed be the same as text_opcode_size(tp->opcode). Use this to
remove this field from the structure.

Sadly, due to 8 byte alignment, this only increases the structure
padding.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/kernel/alternative.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -938,7 +938,6 @@ static void do_sync_core(void *info)
 
 struct text_poke_loc {
 	void *addr;
-	int len;
 	s32 rel32;
 	u8 opcode;
 	const u8 text[POKE_MAX_OPCODE_SIZE];
@@ -965,6 +964,7 @@ int notrace poke_int3_handler(struct pt_
 {
 	struct text_poke_loc *tp;
 	void *ip;
+	int len;
 
 	/*
 	 * Having observed our INT3 instruction, we now must observe
@@ -1004,7 +1004,8 @@ int notrace poke_int3_handler(struct pt_
 			return 0;
 	}
 
-	ip += tp->len;
+	len = text_opcode_size(tp->opcode);
+	ip += len;
 
 	switch (tp->opcode) {
 	case INT3_INSN_OPCODE:
@@ -1085,10 +1086,12 @@ static void text_poke_bp_batch(struct te
 	 * Second step: update all but the first byte of the patched range.
 	 */
 	for (do_sync = 0, i = 0; i < nr_entries; i++) {
-		if (tp[i].len - sizeof(int3) > 0) {
+		int len = text_opcode_size(tp[i].opcode);
+
+		if (len - sizeof(int3) > 0) {
 			text_poke((char *)tp[i].addr + sizeof(int3),
 				  (const char *)tp[i].text + sizeof(int3),
-				  tp[i].len - sizeof(int3));
+				  len - sizeof(int3));
 			do_sync++;
 		}
 	}
@@ -1141,7 +1144,6 @@ void text_poke_loc_init(struct text_poke
 	BUG_ON(len != insn.length);
 
 	tp->addr = addr;
-	tp->len = len;
 	tp->opcode = insn.opcode.bytes[0];
 
 	switch (tp->opcode) {



  parent reply	other threads:[~2019-11-11 14:48 UTC|newest]

Thread overview: 106+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-11 13:12 [PATCH -v5 00/17] Rewrite x86/ftrace to use text_poke (and more) Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 01/17] x86/alternatives: Teach text_poke_bp() to emulate instructions Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 02/17] x86/alternatives: Update int3_emulate_push() comment Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 03/17] x86/alternatives,jump_label: Provide better text_poke() batching interface Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] x86/alternatives, jump_label: " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 04/17] x86/alternatives: Add and use text_gen_insn() helper Peter Zijlstra
2019-11-12 17:10   ` Steven Rostedt
2019-11-12 22:25     ` Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 05/17] x86/ftrace: Use text_poke() Peter Zijlstra
2019-11-12 18:25   ` Steven Rostedt
2019-11-12 22:24     ` Peter Zijlstra
2019-11-12 22:48       ` Steven Rostedt
2019-11-13  9:01         ` Peter Zijlstra
2019-11-13 14:27           ` Steven Rostedt
2019-11-14 13:18             ` Peter Zijlstra
2019-11-14 13:56               ` Steven Rostedt
2019-11-14 14:05                 ` Peter Zijlstra
2019-11-13  8:53       ` Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-11-16 20:46     ` Borislav Petkov
2019-11-18 17:35       ` [PATCH] x86/ftrace: Mark ftrace_modify_code_direct() __ref Borislav Petkov
2019-11-18 17:52         ` Steven Rostedt
2019-11-19  9:55       ` [tip: core/kprobes] " tip-bot2 for Borislav Petkov
2019-12-04  8:33       ` tip-bot2 for Borislav Petkov
2019-12-04  8:33   ` [tip: core/kprobes] x86/ftrace: Use text_poke() tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 06/17] x86/mm: Remove set_kernel_text_r[ow]() Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 07/17] x86/alternative: Add text_opcode_size() Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 08/17] x86/ftrace: Use text_gen_insn() Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` Peter Zijlstra [this message]
2019-11-15  9:43   ` [tip: core/kprobes] x86/alternative: Remove text_poke_loc::len tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 10/17] x86/alternative: Shrink text_poke_loc Peter Zijlstra
2019-11-15  9:43   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 11/17] x86/kprobes: Convert to text-patching.h Peter Zijlstra
2019-11-19 16:56   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 12/17] x86/kprobes: Fix ordering Peter Zijlstra
2019-11-13 14:31   ` Paul E. McKenney
2019-11-13 15:42   ` Mathieu Desnoyers
2019-11-14 13:53     ` Peter Zijlstra
2019-11-14 15:06       ` Mathieu Desnoyers
2019-11-14 15:13         ` Paul E. McKenney
2019-11-14 15:22           ` Mathieu Desnoyers
2019-11-14 15:28             ` Peter Zijlstra
2019-11-14 15:30               ` Mathieu Desnoyers
2019-11-14 15:42                 ` Peter Zijlstra
2019-11-14 15:58                   ` Peter Zijlstra
2019-11-19 16:56   ` [tip: core/kprobes] x86/kprobes: Fix ordering while text-patching tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 13/17] arm/ftrace: Use __patch_text_real() Peter Zijlstra
2019-11-11 16:47   ` Will Deacon
2019-11-11 17:19     ` Peter Zijlstra
2019-11-11 17:25       ` Peter Zijlstra
2019-11-12 11:29         ` Will Deacon
2019-11-13  9:26           ` [PATCH -v5mkII 13/17] arm/ftrace: Use __patch_text() Peter Zijlstra
2019-11-19 16:56             ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33             ` tip-bot2 for Peter Zijlstra
2020-01-22 21:26               ` Dmitry Osipenko
2020-02-07 10:17                 ` Peter Zijlstra
2020-02-07 10:26                   ` Peter Zijlstra
2020-02-07 11:27                 ` Peter Zijlstra
2020-02-07 16:47                   ` Dmitry Osipenko
2020-01-08 12:22             ` [PATCH -v5mkII 13/17] " Arnd Bergmann
2020-01-08 14:16               ` Steven Rostedt
2020-01-08 14:22                 ` Arnd Bergmann
2019-11-11 13:13 ` [PATCH -v5 14/17] module: Remove set_all_modules_text_*() Peter Zijlstra
2019-11-19 16:56   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 15/17] ftrace: Rework event_create_dir() Peter Zijlstra
2019-11-14 14:07   ` Steven Rostedt
2019-11-19 16:56   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 16/17] x86/kprobe: Add comments to arch_{,un}optimize_kprobes() Peter Zijlstra
2019-11-19 16:56   ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 17/17] x86/alternative: Use INT3_INSN_SIZE Peter Zijlstra
2019-11-19 16:56   ` [tip: core/kprobes] x86/alternatives: " tip-bot2 for Peter Zijlstra
2019-12-04  8:33   ` tip-bot2 for Peter Zijlstra
2019-11-11 19:47 ` [PATCH -v5 00/17] Rewrite x86/ftrace to use text_poke (and more) Alexei Starovoitov
2019-11-11 20:39   ` Peter Zijlstra
2019-11-11 20:42   ` Peter Zijlstra
2019-11-11 20:56     ` Alexei Starovoitov
2019-11-12 18:26 ` Steven Rostedt
2019-11-25  3:55 ` Masami Hiramatsu
2019-11-25  6:47   ` Masami Hiramatsu
2019-11-25 17:32   ` Steven Rostedt
2019-11-26  0:11     ` Masami Hiramatsu
2019-11-26  8:58       ` Masami Hiramatsu
2019-11-26  9:58         ` Masami Hiramatsu
2019-11-26 23:48           ` Masami Hiramatsu
     [not found]             ` <CAADnVQK4twuXzFhD-qLHmCVK0n1h-GDENQLu+4PVV3Hp++R6kQ@mail.gmail.com>
2019-11-27  4:32               ` Alexei Starovoitov
2019-11-27  5:01                 ` Alexei Starovoitov
2019-11-27  6:41                 ` Masami Hiramatsu

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