[PATCH 2/2] asmlinkage_protect sys_io_getevents

From: Roland McGrath
Date: Thu Apr 10 2008 - 18:39:02 EST


Use asmlinkage_protect in sys_io_getevents, because GCC for i386 with
CONFIG_FRAME_POINTER=n can decide to clobber an argument word on the
stack, i.e. the user struct pt_regs. Here the problem is not a tail
call, but just the compiler's use of the stack when it inlines and
optimizes the body of the called function. This seems to avoid it.

Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
---
fs/aio.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 6af9219..60a4cd4 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1790,6 +1790,7 @@ asmlinkage long sys_io_getevents(aio_context_t ctx_id,
put_ioctx(ioctx);
}

+ asmlinkage_protect(5, ret, ctx_id, min_nr, nr, events, timeout);
return ret;
}

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