Thread (5 messages) 5 messages, 2 authors, 2021-01-27

Re: [PATCH v3 1/2] bio: limit bio max size

From: Changheun Lee <hidden>
Date: 2021-01-27 06:07:26
Also in: lkml

Possibly related (same subject, not in this thread)

On 2021/01/27 9:36, Changheun Lee wrote:
quoted
quoted
quoted
+
 /**
  * bio_reset - reinitialize a bio
  * @bio:	bio to reset
@@ -877,7 +892,7 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page,
 		struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
 
 		if (page_is_mergeable(bv, page, len, off, same_page)) {
-			if (bio->bi_iter.bi_size > UINT_MAX - len) {
+			if (bio->bi_iter.bi_size > bio_max_size(bio) - len) {
 				*same_page = false;
 				return false;
 			}
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 1edda614f7ce..cdb134ca7bf5 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -100,6 +100,8 @@ static inline void *bio_data(struct bio *bio)
 	return NULL;
 }
 
+extern unsigned int bio_max_size(struct bio *);
No need for extern.
It's just for compile warning in my test environment.
I'll remove it too. But I think compile warning could be in the other
.c file which includes bio.h. Is it OK?
Hmmm... not having extern should not generate a compilation warning. There are
tons of functions declared without extern in header files in the kernel. What
compiler are you using ?
Compiler imformation is below.

CROSS_COMPILE: android/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android-
CC: android/prebuilts/clang/host/linux-x86/clang-r383902/bin/clang
CLANG_TRIPLE: android/prebuilts/clang/host/linux-x86/clang-r383902/bin/aarch64-linux-gnu-
CROSS_COMPILE_COMPAT: android/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi-

-- 
Damien Le Moal
Western Digital Research
---
Changheun Lee
Samsung Electronics
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