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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, jpoimboe@redhat.com, jbaron@akamai.com,
	rostedt@goodmis.org, ardb@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org
Subject: [PATCH 08/13] jump_label: Free jump_entry::key bit1 for build use
Date: Thu, 06 May 2021 21:34:00 +0200	[thread overview]
Message-ID: <20210506194157.906893264@infradead.org> (raw)
In-Reply-To: 20210506193352.719596001@infradead.org

Have jump_label_init() set jump_entry::key bit1 to either 0 ot 1
unconditionally. This makes it available for build-time games.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/jump_label.h |    7 +++++--
 kernel/jump_label.c        |   10 ++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)

--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -171,9 +171,12 @@ static inline bool jump_entry_is_init(co
 	return (unsigned long)entry->key & 2UL;
 }
 
-static inline void jump_entry_set_init(struct jump_entry *entry)
+static inline void jump_entry_set_init(struct jump_entry *entry, bool set)
 {
-	entry->key |= 2;
+	if (set)
+		entry->key |= 2;
+	else
+		entry->key &= ~2;
 }
 
 static inline int jump_entry_size(struct jump_entry *entry)
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -475,13 +475,14 @@ void __init jump_label_init(void)
 
 	for (iter = iter_start; iter < iter_stop; iter++) {
 		struct static_key *iterk;
+		bool in_init;
 
 		/* rewrite NOPs */
 		if (jump_label_type(iter) == JUMP_LABEL_NOP)
 			arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
 
-		if (init_section_contains((void *)jump_entry_code(iter), 1))
-			jump_entry_set_init(iter);
+		in_init = init_section_contains((void *)jump_entry_code(iter), 1);
+		jump_entry_set_init(iter, in_init);
 
 		iterk = jump_entry_key(iter);
 		if (iterk == key)
@@ -626,9 +627,10 @@ static int jump_label_add_module(struct
 
 	for (iter = iter_start; iter < iter_stop; iter++) {
 		struct static_key *iterk;
+		bool in_init;
 
-		if (within_module_init(jump_entry_code(iter), mod))
-			jump_entry_set_init(iter);
+		in_init = within_module_init(jump_entry_code(iter), mod);
+		jump_entry_set_init(iter, in_init);
 
 		iterk = jump_entry_key(iter);
 		if (iterk == key)



  parent reply	other threads:[~2021-05-06 19:44 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-06 19:33 [PATCH 00/13] jump_label: Yet another attempt at variable sized jump_labels Peter Zijlstra
2021-05-06 19:33 ` [PATCH 01/13] objtool: Rewrite hashtable sizing Peter Zijlstra
2021-05-12 10:41   ` Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-06-10 18:14   ` [PATCH 01/13] " Nathan Chancellor
2021-06-10 18:43     ` Peter Zijlstra
2021-06-10 18:54       ` Nathan Chancellor
2021-06-10 18:50     ` Sami Tolvanen
2021-06-10 19:33       ` Peter Zijlstra
2021-06-10 19:43         ` Sami Tolvanen
2021-06-10 20:59         ` Nathan Chancellor
2021-06-14 13:19         ` [tip: objtool/core] objtool: Improve reloc hash size guestimate tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 02/13] x86,objtool: Dont exclude arch/x86/realmode/ Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] x86, objtool: " tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 03/13] jump_label, x86: Strip ASM jump_label support Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 04/13] jump_label, x86: Factor out the __jump_table generation Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 05/13] jump_label, x86: Improve error when we fail expected text Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 06/13] jump_label, x86: Introduce jump_entry_size() Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:33 ` [PATCH 07/13] jump_label, x86: Add variable length patching support Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-13 14:16   ` [PATCH 07.5/13] jump_label,x86: Remove unused JUMP_LABEL_NOP_SIZE Peter Zijlstra
2021-05-14  7:01     ` [tip: objtool/core] jump_label/x86: " tip-bot2 for Peter Zijlstra
2021-05-06 19:34 ` Peter Zijlstra [this message]
2021-05-12 13:19   ` [tip: objtool/core] jump_label: Free jump_entry::key bit1 for build use tip-bot2 for Peter Zijlstra
2021-05-06 19:34 ` [PATCH 09/13] jump_label,x86: Emit short JMP Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] jump_label, x86: " tip-bot2 for Peter Zijlstra
2021-05-06 19:34 ` [PATCH 10/13] objtool: Decode jump_entry::key addend Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:34 ` [PATCH 11/13] objtool: Rewrite jump_label instructions Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-06 19:34 ` [PATCH 12/13] objtool: Provide stats for jump_labels Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] " tip-bot2 for Peter Zijlstra
2021-05-13 14:15   ` [PATCH 12.5/13] objtool: Reflow handle_jump_alt() Peter Zijlstra
2021-05-06 19:34 ` [PATCH 13/13] jump_label,x86: Allow short NOPs Peter Zijlstra
2021-05-06 19:49   ` Peter Zijlstra
2021-05-12 13:19   ` [tip: objtool/core] jump_label, x86: " tip-bot2 for Peter Zijlstra
2021-05-18 19:50     ` Peter Zijlstra
2021-05-18 20:24       ` Peter Zijlstra
2021-05-19  0:44         ` Josh Poimboeuf
2021-05-19  6:56           ` Peter Zijlstra
2021-06-29 20:00             ` Matthew Wilcox
2021-06-29 20:35               ` Matthew Wilcox
2021-06-30  7:07                 ` Peter Zijlstra
2021-06-30  7:38                   ` Peter Zijlstra

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