[PATCH 21/41] x86/alternatives: Assert that text_poke_int3_handler() can only ever handle 'tp_vec[]' based requests
From: Ingo Molnar
Date: Thu Mar 27 2025 - 17:00:20 EST
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/alternative.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index f75806d699be..883c2146ce54 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2510,6 +2510,10 @@ static __always_inline int patch_cmp(const void *key, const void *elt)
return 0;
}
+#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct text_poke_int3_loc))
+static struct text_poke_int3_loc tp_vec[TP_VEC_MAX];
+static int tp_vec_nr;
+
noinstr int text_poke_int3_handler(struct pt_regs *regs)
{
struct text_poke_int3_vec *desc;
@@ -2534,6 +2538,8 @@ noinstr int text_poke_int3_handler(struct pt_regs *regs)
if (!desc)
return 0;
+ WARN_ON_ONCE(desc->vec != tp_vec);
+
/*
* Discount the INT3. See text_poke_int3_batch().
*/
@@ -2592,10 +2598,6 @@ noinstr int text_poke_int3_handler(struct pt_regs *regs)
return ret;
}
-#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct text_poke_int3_loc))
-static struct text_poke_int3_loc tp_vec[TP_VEC_MAX];
-static int tp_vec_nr;
-
/**
* text_poke_int3_batch() -- update instructions on live kernel on SMP
* @tp: vector of instructions to patch
--
2.45.2