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authorNathan Chancellor <nathan@kernel.org>2024-10-30 09:14:49 -0700
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>2024-10-31 11:00:58 +0900
commit3fbff988892993a144d0f47db0348c18b4621393 (patch)
tree2f6cc97c4d457e696cecddd8b2f5a94250297609
parentda93dd931baa921ee31796e0cd6402d995e1e4fc (diff)
downloadlwn-3fbff988892993a144d0f47db0348c18b4621393.tar.gz
lwn-3fbff988892993a144d0f47db0348c18b4621393.zip
kprobes: Use struct_size() in __get_insn_slot()
__get_insn_slot() allocates 'struct kprobe_insn_page' using a custom structure size calculation macro, KPROBE_INSN_PAGE_SIZE. Replace KPROBE_INSN_PAGE_SIZE with the struct_size() macro, which is the preferred way to calculate the size of flexible structures in the kernel because it handles overflow and makes it easier to change and audit how flexible structures are allocated across the entire tree. Link: https://lore.kernel.org/all/20241030-kprobes-fix-counted-by-annotation-v1-2-8f266001fad0@kernel.org/ (Masami modofied this to be applicable without the 1st patch in the series.) Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
-rw-r--r--kernel/kprobes.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 5381c6571fa2..b027a4030976 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -95,10 +95,6 @@ struct kprobe_insn_page {
char slot_used[];
};
-#define KPROBE_INSN_PAGE_SIZE(slots) \
- (offsetof(struct kprobe_insn_page, slot_used) + \
- (sizeof(char) * (slots)))
-
static int slots_per_page(struct kprobe_insn_cache *c)
{
return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t));
@@ -175,7 +171,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
goto retry;
/* All out of space. Need to allocate a new page. */
- kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL);
+ kip = kmalloc(struct_size(kip, slot_used, slots_per_page(c)), GFP_KERNEL);
if (!kip)
goto out;