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From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
	"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: [tip: core/kprobes] x86/alternative: Shrink text_poke_loc
Date: Fri, 15 Nov 2019 09:43:08 -0000	[thread overview]
Message-ID: <157381098810.29467.5756130583510586766.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20191111132458.047052889@infradead.org>

The following commit has been merged into the core/kprobes branch of tip:

Commit-ID:     54d41ef26da6820cf31b243357108dbbf11c6129
Gitweb:        https://git.kernel.org/tip/54d41ef26da6820cf31b243357108dbbf11c6129
Author:        Peter Zijlstra <peterz@infradead.org>
AuthorDate:    Wed, 09 Oct 2019 12:26:53 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 15 Nov 2019 09:07:43 +01:00

x86/alternative: Shrink text_poke_loc

Employ the fact that all text must be within a s32 displacement of one
another to shrink the text_poke_loc::addr field. Make it relative to
_stext.

This then shrinks struct text_poke_loc to 16 bytes, and consequently
increases TP_VEC_MAX from 170 to 256.

Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132458.047052889@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/alternative.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 6e3ee73..526cc5f 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -937,7 +937,7 @@ static void do_sync_core(void *info)
 }
 
 struct text_poke_loc {
-	void *addr;
+	s32 rel_addr; /* addr := _stext + rel_addr */
 	s32 rel32;
 	u8 opcode;
 	const u8 text[POKE_MAX_OPCODE_SIZE];
@@ -948,13 +948,18 @@ static struct bp_patching_desc {
 	int nr_entries;
 } bp_patching;
 
+static inline void *text_poke_addr(struct text_poke_loc *tp)
+{
+	return _stext + tp->rel_addr;
+}
+
 static int notrace patch_cmp(const void *key, const void *elt)
 {
 	struct text_poke_loc *tp = (struct text_poke_loc *) elt;
 
-	if (key < tp->addr)
+	if (key < text_poke_addr(tp))
 		return -1;
-	if (key > tp->addr)
+	if (key > text_poke_addr(tp))
 		return 1;
 	return 0;
 }
@@ -1000,7 +1005,7 @@ int notrace poke_int3_handler(struct pt_regs *regs)
 			return 0;
 	} else {
 		tp = bp_patching.vec;
-		if (tp->addr != ip)
+		if (text_poke_addr(tp) != ip)
 			return 0;
 	}
 
@@ -1078,7 +1083,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries
 	 * First step: add a int3 trap to the address that will be patched.
 	 */
 	for (i = 0; i < nr_entries; i++)
-		text_poke(tp[i].addr, &int3, sizeof(int3));
+		text_poke(text_poke_addr(&tp[i]), &int3, sizeof(int3));
 
 	on_each_cpu(do_sync_core, NULL, 1);
 
@@ -1089,7 +1094,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries
 		int len = text_opcode_size(tp[i].opcode);
 
 		if (len - sizeof(int3) > 0) {
-			text_poke((char *)tp[i].addr + sizeof(int3),
+			text_poke(text_poke_addr(&tp[i]) + sizeof(int3),
 				  (const char *)tp[i].text + sizeof(int3),
 				  len - sizeof(int3));
 			do_sync++;
@@ -1113,7 +1118,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries
 		if (tp[i].text[0] == INT3_INSN_OPCODE)
 			continue;
 
-		text_poke(tp[i].addr, tp[i].text, sizeof(int3));
+		text_poke(text_poke_addr(&tp[i]), tp[i].text, sizeof(int3));
 		do_sync++;
 	}
 
@@ -1143,7 +1148,7 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 	BUG_ON(!insn_complete(&insn));
 	BUG_ON(len != insn.length);
 
-	tp->addr = addr;
+	tp->rel_addr = addr - (void *)_stext;
 	tp->opcode = insn.opcode.bytes[0];
 
 	switch (tp->opcode) {
@@ -1192,7 +1197,7 @@ static bool tp_order_fail(void *addr)
 		return true;
 
 	tp = &tp_vec[tp_vec_nr - 1];
-	if ((unsigned long)tp->addr > (unsigned long)addr)
+	if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr)
 		return true;
 
 	return false;

  reply	other threads:[~2019-11-15  9:43 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 ` [PATCH -v5 09/17] x86/alternative: Remove text_poke_loc::len 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 10/17] x86/alternative: Shrink text_poke_loc Peter Zijlstra
2019-11-15  9:43   ` tip-bot2 for Peter Zijlstra [this message]
2019-12-04  8:33   ` [tip: core/kprobes] " 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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