tree 37019047caf24df91f617677f72b378d1e23d82e
parent 7c7e9425f114a109b07be2c2c1c6c169e34e9bb3
author Jeremy Fitzhardinge <jeremy@goop.org> 1166778681 -0800
committer Linus Torvalds <torvalds@woody.osdl.org> 1166806551 -0800

[PATCH] ptrace: Fix EFL_OFFSET value according to i386 pda changes

The PDA patches introduced a bug in ptrace: it reads eflags from the wrong
place on the target's stack, but writes it back to the correct place.  The
result is a corrupted eflags, which is most visible when it turns interrupts
off unexpectedly.

This patch fixes this by making the ptrace code a little less fragile.  It
changes [gs]et_stack_long to take a straightforward byte offset into struct
pt_regs, rather than requiring all callers to do a sizeof(struct pt_regs)
offset adjustment.  This means that the eflag's offset (EFL_OFFSET) on the
target stack can be simply computed with offsetof().

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Frederik Deweerdt <deweerdt@free.fr>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>