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From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Borislav Petkov <bp@alien8.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 22/53] x86/alternatives: Use non-inverted logic instead of 'tp_order_fail()'
Date: Fri, 11 Apr 2025 07:40:34 +0200	[thread overview]
Message-ID: <20250411054105.2341982-23-mingo@kernel.org> (raw)
In-Reply-To: <20250411054105.2341982-1-mingo@kernel.org>

tp_order_fail() uses inverted logic: it returns true in case something
is false, which is only a plus at the IOCCC.

Instead rename it to regular parity as 'text_poke_addr_ordered()',
and adjust the code accordingly.

Also add a comment explaining how the address ordering should be
understood.

No change in functionality intended.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/alternative.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index d3d250dcefca..c9fd31d512b0 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2841,28 +2841,34 @@ static void text_poke_int3_loc_init(struct smp_text_poke_loc *tp, void *addr,
  * We hard rely on the tp_vec being ordered; ensure this is so by flushing
  * early if needed.
  */
-static bool tp_order_fail(void *addr)
+static bool text_poke_addr_ordered(void *addr)
 {
 	struct smp_text_poke_loc *tp;
 
 	if (!tp_vec_nr)
-		return false;
+		return true;
 
 	if (!addr) /* force */
-		return true;
+		return false;
 
-	tp = &tp_vec[tp_vec_nr - 1];
+	/*
+	 * If the last current entry's address is higher than the
+	 * new entry's address we'd like to add, then ordering
+	 * is violated and we must first flush all pending patching
+	 * requests:
+	 */
+	tp = &tp_vec[tp_vec_nr-1];
 	if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr)
-		return true;
+		return false;
 
-	return false;
+	return true;
 }
 
 static void smp_text_poke_batch_flush(void *addr)
 {
 	lockdep_assert_held(&text_mutex);
 
-	if (tp_vec_nr == TP_VEC_MAX || tp_order_fail(addr)) {
+	if (tp_vec_nr == TP_VEC_MAX || !text_poke_addr_ordered(addr)) {
 		smp_text_poke_batch_process(tp_vec, tp_vec_nr);
 		tp_vec_nr = 0;
 	}
-- 
2.45.2


  parent reply	other threads:[~2025-04-11  5:42 UTC|newest]

Thread overview: 105+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-11  5:40 [PATCH -v3 00/53] Simplify, reorganize and clean up the x86 text-patching code (alternative.c) Ingo Molnar
2025-04-11  5:40 ` [PATCH 01/53] x86/alternatives: Improve code-patching scalability by removing false sharing in poke_int3_handler() Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Eric Dumazet
2025-04-11  5:40 ` [PATCH 02/53] x86/alternatives: Document the text_poke_bp_batch() synchronization rules a bit more Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2025-04-11  5:40 ` [PATCH 03/53] x86/alternatives: Rename 'struct bp_patching_desc' to 'struct int3_patching_desc' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] x86/alternatives: Rename 'struct bp_patching_desc' to 'struct text_poke_int3_vec' tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 04/53] x86/alternatives: Rename 'bp_refs' to 'int3_refs' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] x86/alternatives: Rename 'bp_refs' to 'text_poke_array_refs' tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 05/53] x86/alternatives: Rename 'text_poke_bp_batch()' to 'smp_text_poke_batch_process()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 06/53] x86/alternatives: Rename 'text_poke_bp()' to 'smp_text_poke_single()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 07/53] x86/alternatives: Rename 'poke_int3_handler()' to 'smp_text_poke_int3_handler()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 08/53] x86/alternatives: Rename 'poking_mm' to 'text_poke_mm' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 09/53] x86/alternatives: Rename 'poking_addr' to 'text_poke_mm_addr' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 10/53] x86/alternatives: Rename 'bp_desc' to 'int3_desc' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 11/53] x86/alternatives: Remove duplicate 'text_poke_early()' prototype Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 12/53] x86/alternatives: Update comments in int3_emulate_push() Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 13/53] x86/alternatives: Remove the confusing, inaccurate & unnecessary 'temp_mm_state_t' abstraction Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 14/53] x86/alternatives: Rename 'text_poke_flush()' to 'smp_text_poke_batch_flush()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 15/53] x86/alternatives: Rename 'text_poke_finish()' to 'smp_text_poke_batch_finish()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 16/53] x86/alternatives: Rename 'text_poke_queue()' to 'smp_text_poke_batch_add()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 17/53] x86/alternatives: Rename 'text_poke_loc_init()' to 'text_poke_int3_loc_init()' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 18/53] x86/alternatives: Rename 'struct text_poke_loc' to 'struct smp_text_poke_loc' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 19/53] x86/alternatives: Rename 'struct int3_patching_desc' to 'struct text_poke_int3_vec' Ingo Molnar
2025-04-11  5:40 ` [PATCH 20/53] x86/alternatives: Rename 'int3_desc' to 'int3_vec' Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 21/53] x86/alternatives: Add text_mutex) assert to smp_text_poke_batch_flush() Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` Ingo Molnar [this message]
2025-04-11 10:02   ` [tip: x86/alternatives] x86/alternatives: Use non-inverted logic instead of 'tp_order_fail()' tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 23/53] x86/alternatives: Remove the 'addr == NULL means forced-flush' hack from smp_text_poke_batch_finish()/smp_text_poke_batch_flush()/text_poke_addr_ordered() Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 24/53] x86/alternatives: Simplify smp_text_poke_single() by using tp_vec and existing APIs Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 25/53] x86/alternatives: Assert that smp_text_poke_int3_handler() can only ever handle 'tp_vec[]' based requests Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 26/53] x86/alternatives: Assert input parameters in smp_text_poke_batch_process() Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 27/53] x86/alternatives: Introduce 'struct smp_text_poke_array' and move tp_vec and tp_vec_nr to it Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 28/53] x86/alternatives: Remove the tp_vec indirection Ingo Molnar
2025-04-11 10:02   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 29/53] x86/alternatives: Rename 'try_get_desc()' to 'try_get_text_poke_array()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 30/53] x86/alternatives: Rename 'put_desc()' to 'put_text_poke_array()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 31/53] x86/alternatives: Simplify try_get_text_poke_array() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 32/53] x86/alternatives: Simplify smp_text_poke_int3_handler() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 33/53] x86/alternatives: Simplify smp_text_poke_batch_process() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 34/53] x86/alternatives: Rename 'int3_refs' to 'text_poke_array_refs' Ingo Molnar
2025-04-11  5:40 ` [PATCH 35/53] x86/alternatives: Move the text_poke_array manipulation into text_poke_int3_loc_init() and rename it to __smp_text_poke_batch_add() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 36/53] x86/alternatives: Remove the mixed-patching restriction on smp_text_poke_single() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 37/53] x86/alternatives: Document 'smp_text_poke_single()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 38/53] x86/alternatives: Add documentation for smp_text_poke_batch_add() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 39/53] x86/alternatives: Move text_poke_array completion from smp_text_poke_batch_finish() and smp_text_poke_batch_flush() to smp_text_poke_batch_process() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 40/53] x86/alternatives: Rename 'text_poke_sync()' to 'smp_text_poke_sync_each_cpu()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 41/53] x86/alternatives: Simplify text_poke_addr_ordered() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 42/53] x86/alternatives: Constify text_poke_addr() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 43/53] x86/alternatives: Simplify and clean up patch_cmp() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 44/53] x86/alternatives: Standardize on 'tpl' local variable names for 'struct smp_text_poke_loc *' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 45/53] x86/alternatives: Rename 'TP_ARRAY_NR_ENTRIES_MAX' to 'TEXT_POKE_ARRAY_MAX' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 46/53] x86/alternatives: Rename 'POKE_MAX_OPCODE_SIZE' to 'TEXT_POKE_MAX_OPCODE_SIZE' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:40 ` [PATCH 47/53] x86/alternatives: Simplify the #include section Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 48/53] x86/alternatives: Move declarations of vmlinux.lds.S defined section symbols to <asm/alternative.h> Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 49/53] x86/alternatives: Remove 'smp_text_poke_batch_flush()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 50/53] x86/alternatives: Update the comments in smp_text_poke_batch_process() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 51/53] x86/alternatives: Rename 'apply_relocation()' to 'text_poke_apply_relocation()' Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 52/53] x86/alternatives: Add comment about noinstr expectations Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Ingo Molnar
2025-04-11  5:41 ` [PATCH 53/53] x86/alternatives: Make smp_text_poke_batch_process() subsume smp_text_poke_batch_finish() Ingo Molnar
2025-04-11 10:01   ` [tip: x86/alternatives] " tip-bot2 for Nikolay Borisov

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