From: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
To: Jintao Yin <nicememory@gmail.com>, phillip@squashfs.org.uk
Cc: bagasdotme@gmail.com, hsinyi@chromium.org,
linux-kernel@vger.kernel.org, marcmiltenberger@gmail.com,
regressions@leemhuis.info, regressions@lists.linux.dev,
srw@sladewatkins.net
Subject: Re: BISECT result: 6.0.0-RC kernels trigger Firefox snap bug with 6.0.0-rc3 through 6.0.0-rc7
Date: Thu, 20 Oct 2022 18:00:06 +0200 [thread overview]
Message-ID: <d2580643-f58e-c1b0-7671-c5bbb38c05d0@alu.unizg.hr> (raw)
In-Reply-To: <20221020135545.586-1-nicememory@gmail.com>
On 10/20/22 15:55, Jintao Yin wrote:
> Hi all,
>
> After review the details of page actor, the tail bytes may be written to
> a temp buffer instead the last used page. So before diff would wrongly
> memzero a page which is not the tail bytes in.
>
> In this diff fixes it by caculation of the real index the trailing bytes
> in and check if the last used page matches this index. If the page is
> the real tail bytes in, then memzero the trailing bypte of the page.
>
> Please help test and any feedbacks are welcome.
>
> Thanks,
>
> Jintao
Hi, Jintao,
I have very good news. The bug reproducing Firefox windows and tabs
setup that
crashed with core dump in your previous diff now works a OK.
The build from the previous email was v6.0.2+ and this one is 6.1-rc1+.
As a newbie I cannot say anything of importance, but I feel good about this
being done.
Have a nice day!
Mirsad
> diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
> index e56510964b22..e1fafd10a850 100644
> --- a/fs/squashfs/file.c
> +++ b/fs/squashfs/file.c
> @@ -506,8 +506,9 @@ static int squashfs_readahead_fragment(struct page **page,
> squashfs_i(inode)->fragment_size);
> struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
> unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
> + int res = buffer->error;
>
> - if (buffer->error)
> + if (res)
> goto out;
>
> expected += squashfs_i(inode)->fragment_offset;
> @@ -529,7 +530,7 @@ static int squashfs_readahead_fragment(struct page **page,
>
> out:
> squashfs_cache_put(buffer);
> - return buffer->error;
> + return res;
> }
>
> static void squashfs_readahead(struct readahead_control *ractl)
> @@ -557,6 +558,7 @@ static void squashfs_readahead(struct readahead_control *ractl)
> int res, bsize;
> u64 block = 0;
> unsigned int expected;
> + int nr_used_pages;
>
> nr_pages = __readahead_batch(ractl, pages, max_pages);
> if (!nr_pages)
> @@ -593,18 +595,21 @@ static void squashfs_readahead(struct readahead_control *ractl)
>
> res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
>
> - squashfs_page_actor_free(actor);
> + nr_used_pages = squashfs_page_actor_free(actor);
>
> if (res == expected) {
> int bytes;
> + pgoff_t bytes_index;
>
> /* Last page (if present) may have trailing bytes not filled */
> bytes = res % PAGE_SIZE;
> - if (pages[nr_pages - 1]->index == file_end && bytes)
> - memzero_page(pages[nr_pages - 1], bytes,
> + bytes_index = (index << shift) + ((res - bytes) >> PAGE_SHIFT);
> + if (bytes && nr_used_pages > 0 &&
> + pages[nr_used_pages - 1]->index == bytes_index)
> + memzero_page(pages[nr_used_pages - 1], bytes,
> PAGE_SIZE - bytes);
>
> - for (i = 0; i < nr_pages; i++) {
> + for (i = 0; i < nr_used_pages; i++) {
> flush_dcache_page(pages[i]);
> SetPageUptodate(pages[i]);
> }
> diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
> index f1ccad519e28..ee462ef380bf 100644
> --- a/fs/squashfs/file_direct.c
> +++ b/fs/squashfs/file_direct.c
> @@ -26,14 +26,14 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
> struct inode *inode = target_page->mapping->host;
> struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
>
> - int file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT;
> - int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
> - int start_index = target_page->index & ~mask;
> - int end_index = start_index | mask;
> - int i, n, pages, bytes, res = -ENOMEM;
> + pgoff_t file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT;
> + pgoff_t mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1;
> + pgoff_t start_index = target_page->index & ~mask;
> + pgoff_t end_index = start_index | mask;
> + int i, pages, used_pages, bytes, res = -ENOMEM;
> + pgoff_t n, bytes_index;
> struct page **page;
> struct squashfs_page_actor *actor;
> - void *pageaddr;
>
> if (end_index > file_end)
> end_index = file_end;
> @@ -74,7 +74,7 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
> /* Decompress directly into the page cache buffers */
> res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);
>
> - squashfs_page_actor_free(actor);
> + used_pages = squashfs_page_actor_free(actor);
>
> if (res < 0)
> goto mark_errored;
> @@ -86,16 +86,19 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
>
> /* Last page (if present) may have trailing bytes not filled */
> bytes = res % PAGE_SIZE;
> - if (page[pages - 1]->index == end_index && bytes) {
> - pageaddr = kmap_local_page(page[pages - 1]);
> - memset(pageaddr + bytes, 0, PAGE_SIZE - bytes);
> - kunmap_local(pageaddr);
> + bytes_index = start_index + ((res - bytes) >> PAGE_SHIFT);
> + if (used_pages > 0 && bytes &&
> + page[used_pages - 1]->index == bytes_index) {
> + memzero_page(page[used_pages - 1], bytes,
> + PAGE_SIZE - bytes);
> }
>
> /* Mark pages as uptodate, unlock and release */
> for (i = 0; i < pages; i++) {
> - flush_dcache_page(page[i]);
> - SetPageUptodate(page[i]);
> + if (i < used_pages) {
> + flush_dcache_page(page[i]);
> + SetPageUptodate(page[i]);
> + }
> unlock_page(page[i]);
> if (page[i] != target_page)
> put_page(page[i]);
> @@ -112,8 +115,10 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
> for (i = 0; i < pages; i++) {
> if (page[i] == NULL || page[i] == target_page)
> continue;
> - flush_dcache_page(page[i]);
> - SetPageError(page[i]);
> + if (i < used_pages) {
> + flush_dcache_page(page[i]);
> + SetPageError(page[i]);
> + }
> unlock_page(page[i]);
> put_page(page[i]);
> }
> diff --git a/fs/squashfs/page_actor.h b/fs/squashfs/page_actor.h
> index 95ffbb543d91..c2c5c3937ef9 100644
> --- a/fs/squashfs/page_actor.h
> +++ b/fs/squashfs/page_actor.h
> @@ -29,10 +29,12 @@ extern struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
> extern struct squashfs_page_actor *squashfs_page_actor_init_special(
> struct squashfs_sb_info *msblk,
> struct page **page, int pages, int length);
> -static inline void squashfs_page_actor_free(struct squashfs_page_actor *actor)
> +static inline int squashfs_page_actor_free(struct squashfs_page_actor *actor)
> {
> + int res = actor->next_page;
> kfree(actor->tmp_buffer);
> kfree(actor);
> + return res;
> }
> static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
> {
--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
--
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
prev parent reply other threads:[~2022-10-20 16:00 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 17:57 6.0.0-RC kernels trigger Firefox snap bug with 6.0.0-rc3 through 6.0.0-rc7 Mirsad Goran Todorovac
2022-09-30 10:48 ` BUG: " Mirsad Todorovac
2022-09-30 11:21 ` Slade Watkins
2022-09-30 11:44 ` Mirsad Todorovac
2022-09-30 12:03 ` Slade Watkins
2022-09-30 18:27 ` Slade Watkins
2022-10-03 8:18 ` Mirsad Goran Todorovac
2022-10-07 8:47 ` Slade Watkins
2022-10-07 10:55 ` Mirsad Goran Todorovac
2022-10-06 10:39 ` Marc Miltenberger
2022-10-06 16:27 ` Slade Watkins
2022-10-06 12:00 ` Thorsten Leemhuis
2022-10-06 12:25 ` Thorsten Leemhuis
2022-10-06 12:43 ` Mirsad Todorovac
2022-10-06 13:23 ` Thorsten Leemhuis
[not found] ` <c05134cc-92fa-dac2-e738-cf6fae194521@alu.unizg.hr>
2022-10-06 16:58 ` Thorsten Leemhuis
[not found] ` <f23494b5-b4ea-a32a-e260-4541039dedc8@alu.unizg.hr>
2022-10-07 6:09 ` Mirsad Goran Todorovac
2022-10-07 6:31 ` Mirsad Goran Todorovac
2022-10-08 13:41 ` Mirsad Goran Todorovac
2022-10-08 16:46 ` Mirsad Goran Todorovac
[not found] ` <c40786ab-8b3b-9b64-683f-dac589c024df@alu.unizg.hr>
2022-10-09 6:45 ` BUG reproduced: " Thorsten Leemhuis
2022-10-09 22:45 ` Slade Watkins
2022-10-11 17:53 ` Mirsad Goran Todorovac
2022-10-12 6:05 ` Mirsad Todorovac
2022-10-12 22:58 ` Slade Watkins
2022-10-06 12:38 ` Mirsad Todorovac
2022-10-12 7:46 ` Bagas Sanjaya
2022-10-13 13:24 ` Mirsad Goran Todorovac
2022-10-14 10:32 ` Mirsad Todorovac
2022-10-14 12:28 ` Bagas Sanjaya
2022-10-14 15:06 ` Mirsad Todorovac
2022-10-14 21:44 ` Mirsad Goran Todorovac
[not found] ` <ddf13e46-c091-80b2-3b57-c43ac45435f0@alu.unizg.hr>
2022-10-15 14:59 ` Fwd: BISECT result: " Mirsad Goran Todorovac
2022-10-15 15:32 ` Thorsten Leemhuis
2022-10-15 20:59 ` Phillip Lougher
2022-10-16 12:21 ` Bagas Sanjaya
2022-10-16 12:24 ` Bagas Sanjaya
2022-10-16 12:43 ` Thorsten Leemhuis
2022-11-04 12:06 ` BISECT result: 6.0.0-RC kernels trigger Firefox snap bug with 6.0.0-rc3 through 6.0.0-rc7 #forregzbot Thorsten Leemhuis
2022-10-17 9:45 ` BISECT result: 6.0.0-RC kernels trigger Firefox snap bug with 6.0.0-rc3 through 6.0.0-rc7 Bagas Sanjaya
2022-10-17 12:32 ` Bagas Sanjaya
2022-10-17 17:25 ` Phillip Lougher
2022-10-18 1:38 ` Bagas Sanjaya
2022-10-18 8:35 ` Bagas Sanjaya
2022-10-16 15:55 ` Mirsad Goran Todorovac
2022-10-16 19:55 ` Phillip Lougher
2022-10-16 20:19 ` Phillip Lougher
2022-10-17 2:03 ` Bagas Sanjaya
2022-10-17 2:41 ` Mirsad Goran Todorovac
2022-10-17 4:15 ` Bagas Sanjaya
2022-10-17 8:32 ` Mirsad Goran Todorovac
2022-10-17 13:22 ` Mirsad Goran Todorovac
2022-10-17 13:59 ` Phillip Lougher
2022-10-18 5:49 ` Mirsad Todorovac
2022-10-18 2:15 ` Jintao Yin
2022-10-18 6:52 ` Mirsad Todorovac
2022-10-18 8:24 ` Hsin-Yi Wang
2022-10-18 9:23 ` Mirsad Todorovac
2022-10-18 12:59 ` Bagas Sanjaya
2022-10-18 13:38 ` Phillip Lougher
2022-10-18 13:36 ` Phillip Lougher
2022-10-18 7:23 ` Bagas Sanjaya
2022-10-18 8:33 ` Bagas Sanjaya
2022-10-18 17:15 ` Phillip Lougher
2022-10-18 17:41 ` Mirsad Goran Todorovac
2022-10-18 17:41 ` Phillip Lougher
[not found] ` <1b41bf99-754e-8b90-cc2c-67f50642e2dc@alu.unizg.hr>
2022-10-18 21:34 ` Mirsad Goran Todorovac
2022-10-19 5:17 ` Slade Watkins
2022-10-19 11:07 ` Mirsad Goran Todorovac
2022-10-19 7:53 ` Bagas Sanjaya
2022-10-20 6:59 ` Jintao Yin
2022-10-20 7:43 ` Jintao Yin
2022-10-20 9:51 ` Mirsad Goran Todorovac
2022-10-20 13:02 ` Bagas Sanjaya
2022-10-20 13:55 ` Jintao Yin
2022-10-20 15:00 ` Mirsad Todorovac
2022-10-20 15:45 ` Phillip Lougher
2022-10-20 23:23 ` Bagas Sanjaya
2022-10-20 23:44 ` Slade Watkins
2022-10-21 1:48 ` Phillip Lougher
2022-10-21 7:12 ` Mirsad Goran Todorovac
2022-10-21 8:33 ` Mirsad Goran Todorovac
2022-10-21 3:09 ` Jintao Yin
2022-10-20 15:49 ` Phillip Lougher
2022-10-20 16:00 ` Mirsad Todorovac [this message]
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