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author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2006-04-20 06:41:39 +0900 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-19 16:27:18 -0700 |
commit | 5a7b46b369419493bab4de67b1526e9f76b22a7f (patch) | |
tree | c6c25e52dfd063db53db93d756da77ab67550ec6 /Documentation/magic-number.txt | |
parent | 52824b6b5fa0533e2b2adc9df396d0e9ff6fb02a (diff) | |
download | blackbird-op-linux-5a7b46b369419493bab4de67b1526e9f76b22a7f.tar.gz blackbird-op-linux-5a7b46b369419493bab4de67b1526e9f76b22a7f.zip |
[PATCH] Add more prevent_tail_call()
Those also break userland regs like following.
00000000 <sys_chown16>:
0: 0f b7 44 24 0c movzwl 0xc(%esp),%eax
5: 83 ca ff or $0xffffffff,%edx
8: 0f b7 4c 24 08 movzwl 0x8(%esp),%ecx
d: 66 83 f8 ff cmp $0xffffffff,%ax
11: 0f 44 c2 cmove %edx,%eax
14: 66 83 f9 ff cmp $0xffffffff,%cx
18: 0f 45 d1 cmovne %ecx,%edx
1b: 89 44 24 0c mov %eax,0xc(%esp)
1f: 89 54 24 08 mov %edx,0x8(%esp)
23: e9 fc ff ff ff jmp 24 <sys_chown16+0x24>
where the tailcall at the end overwrites the incoming stack-frame.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
[ I would _really_ like to have a way to tell gcc about calling
conventions. The "prevent_tail_call()" macro is pretty ugly ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation/magic-number.txt')
0 files changed, 0 insertions, 0 deletions