https://github.com/torvalds/linux
Revision 5ae2efb1dea9f537453e841714e3ee2757595aec authored by Oscar Salvador on 29 March 2019, 03:44:01 UTC, committed by Linus Torvalds on 29 March 2019, 17:01:37 UTC
While debugging something, I added a dump_page() into do_swap_page(), and I got the splat from below. The issue happens when dereferencing mapping->host in __dump_page(): ... else if (mapping) { pr_warn("%ps ", mapping->a_ops); if (mapping->host->i_dentry.first) { struct dentry *dentry; dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias); pr_warn("name:\"%pd\" ", dentry); } } ... Swap address space does not contain an inode information, and so mapping->host equals NULL. Although the dump_page() call was added artificially into do_swap_page(), I am not sure if we can hit this from any other path, so it looks worth fixing it. We can easily do that by checking mapping->host first. Link: http://lkml.kernel.org/r/20190318072931.29094-1-osalvador@suse.de Fixes: 1c6fb1d89e73c ("mm: print more information about mapping in __dump_page") Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a7f40cf
Tip revision: 5ae2efb1dea9f537453e841714e3ee2757595aec authored by Oscar Salvador on 29 March 2019, 03:44:01 UTC
mm/debug.c: fix __dump_page when mapping->host is not set
mm/debug.c: fix __dump_page when mapping->host is not set
Tip revision: 5ae2efb
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kernel | ||
lib | ||
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net | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
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.gitattributes | -rw-r--r-- | 30 bytes |
.gitignore | -rw-r--r-- | 1.5 KB |
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COPYING | -rw-r--r-- | 423 bytes |
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Makefile | -rw-r--r-- | 58.4 KB |
README | -rw-r--r-- | 727 bytes |
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