[v1] Simplify, reorganize and clean up the x86 text-patching code (alternative.c)

[PATCH 26/53] x86/alternatives: Assert input parameters in smp_text_poke_batch_process()

Posted by Ingo Molnar 8 months, 1 week ago

At this point the 'tp' input parameter must always be the
global 'tp_vec' array, and 'nr_entries' must always be equal
to 'tp_vec_nr'.

Assert these conditions - which will allow the removal of
a layer of indirection between these values.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/alternative.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index aa369870dfce..ee6ff7660563 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2627,6 +2627,9 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
 
 	lockdep_assert_held(&text_mutex);
 
+	WARN_ON_ONCE(tp != tp_vec);
+	WARN_ON_ONCE(nr_entries != tp_vec_nr);
+
 	int3_vec.vec = tp;
 	int3_vec.nr_entries = nr_entries;
 
-- 
2.45.2

[tip: x86/alternatives] x86/alternatives: Assert input parameters in smp_text_poke_batch_process()

Posted by tip-bot2 for Ingo Molnar 8 months, 1 week ago

The following commit has been merged into the x86/alternatives branch of tip:

Commit-ID:     37725b64a9912292841cea7e9aebfd0f084ed8c0
Gitweb:        https://git.kernel.org/tip/37725b64a9912292841cea7e9aebfd0f084ed8c0
Author:        Ingo Molnar <mingo@kernel.org>
AuthorDate:    Fri, 11 Apr 2025 07:40:38 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 11 Apr 2025 11:01:34 +02:00

x86/alternatives: Assert input parameters in smp_text_poke_batch_process()

At this point the 'tp' input parameter must always be the
global 'tp_vec' array, and 'nr_entries' must always be equal
to 'tp_vec_nr'.

Assert these conditions - which will allow the removal of
a layer of indirection between these values.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-27-mingo@kernel.org
---
 arch/x86/kernel/alternative.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 329f6ee..4fa26a4 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2627,6 +2627,9 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
 
 	lockdep_assert_held(&text_mutex);
 
+	WARN_ON_ONCE(tp != tp_vec);
+	WARN_ON_ONCE(nr_entries != tp_vec_nr);
+
 	int3_vec.vec = tp;
 	int3_vec.nr_entries = nr_entries;