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SubjectRe: [patch] avoid unaligned access when accessing poll stack
Here's a slightly updated version of my patch: it changes the

if (size < sizeof(stack_fds) / 6)
to:
if (size <= sizeof(stack_fds) / 6)

Otherwise this is exactly the same as the version I just posted. The old
code had this problem too but before it only mattered if SELECT_STACK_ALLOC
was a multiple of six.

Signed-off-by: Mitchell Blank Jr <mitch@sfgoth.com>

diff --git a/fs/select.c b/fs/select.c
index 071660f..c46d40c 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -311,7 +311,8 @@ static int core_sys_select(int n, fd_set
{
fd_set_bits fds;
char *bits;
- int ret, size, max_fdset;
+ int ret, max_fdset;
+ unsigned int size;
struct fdtable *fdt;
/* Allocate small arguments on the stack to save memory and be faster */
long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
@@ -335,8 +336,8 @@ static int core_sys_select(int n, fd_set
*/
ret = -ENOMEM;
size = FDS_BYTES(n);
- if (6*size < SELECT_STACK_ALLOC)
- bits = stack_fds;
+ if (size <= sizeof(stack_fds) / 6)
+ bits = (char *) stack_fds;
else
bits = kmalloc(6 * size, GFP_KERNEL);
if (!bits)
@@ -373,7 +374,7 @@ static int core_sys_select(int n, fd_set
ret = -EFAULT;

out:
- if (bits != stack_fds)
+ if (bits != (char *) stack_fds)
kfree(bits);
out_nofds:
return ret;
-
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