user/sven/linux.git/fs/select.c, branch v3.3.4

sys_poll: fix incorrect type for 'timeout' parameter

2012-02-22T01:24:20Z

The 'poll()' system call timeout parameter is supposed to be 'int', not 'long'. Now, the reason this matters is that right now 32-bit compat mode is broken on at least x86-64, because the 32-bit code just calls 'sys_poll()' directly on x86-64, and the 32-bit argument will have been zero-extended, turning a signed 'int' into a large unsigned 'long' value. We could just introduce a 'compat_sys_poll()' function for this, and that may eventually be what we have to do, but since the actual standard poll() semantics is *supposed* to be 'int', and since at least on x86-64 glibc sign-extends the argument before invocing the system call (so nobody can actually use a 64-bit timeout value in user space _anyway_, even in 64-bit binaries), the simpler solution would seem to be to just fix the definition of the system call to match what it should have been from the very start. If it turns out that somebody somehow circumvents the user-level libc 64-bit sign extension and actually uses a large unsigned 64-bit timeout despite that not being how poll() is supposed to work, we will need to do the compat_sys_poll() approach. Reported-by: Thomas Meyer Acked-by: Eric Dumazet Signed-off-by: Linus Torvalds

select: remove unused MAX_SELECT_SECONDS

2011-03-21T04:16:08Z

Remove the leftover from the commit 8ff3e8e85fa6 ("select: switch select() and poll() over to hrtimers"). Signed-off-by: Namhyung Kim Acked-by: Arjan van de Ven Signed-off-by: Al Viro

fs/select.c: fix information leak to userspace

2011-01-13T16:03:12Z

On some architectures __kernel_suseconds_t is int. On these archs struct timeval has padding bytes at the end. This struct is copied to userspace with these padding bytes uninitialized. This leads to leaking of contents of kernel stack memory. This bug was added with v2.6.27-rc5-286-gb773ad4. [akpm@linux-foundation.org: avoid the memset on architectures which don't need it] Signed-off-by: Vasiliy Kulikov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

epoll: make epoll_wait() use the hrtimer range feature

2010-10-28T01:03:18Z

This make epoll use hrtimers for the timeout value which prevents epoll_wait() from timing out up to a millisecond early. This mirrors the behavior of select() and poll(). Signed-off-by: Shawn Bohrer Cc: Al Viro Acked-by: Davide Libenzi Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

select: rename estimate_accuracy() to select_estimate_accuracy()

2010-10-28T01:03:18Z

Make it a subsystem-specific identifier because we wish to amke it non-static in the next patch ("epoll: make epoll_wait() use the hrtimer range feature"). Cc: Shawn Bohrer Cc: Al Viro Cc: Davide Libenzi Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Add generic sys_old_select()

2010-03-12T23:52:32Z

Add a generic implementation of the old select() syscall, which expects its argument in a memory block and switch all architectures over to use it. Signed-off-by: Christoph Hellwig Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mundt Cc: Jeff Dike Cc: Hirokazu Takata Cc: Thomas Gleixner Cc: Ingo Molnar Reviewed-by: H. Peter Anvin Cc: Al Viro Cc: Arnd Bergmann Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: "Luck, Tony" Cc: James Morris Acked-by: Andreas Schwab Acked-by: Russell King Acked-by: Greg Ungerer Acked-by: David Howells Cc: Andreas Schwab Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: use rlimit helpers

2010-03-06T19:26:29Z

Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby Cc: Alexander Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

headers: remove sched.h from poll.h

2009-10-04T22:05:10Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds

poll/select: avoid arithmetic overflow in __estimate_accuracy()

2009-09-23T14:39:27Z

__estimate_accuracy() was prone to integer overflow, for example if *tv == {2147, 483648000} on a 32 bit computer (or even for delays as small as {429, 500000000} if the task is niced). Because the result was already forced between 0 and 100ms, the effect of the overflow was not too problematic, but the use of the hrtimer range feature was not optimal in overflow cases. This patch ensures that there can not be an integer overflow in this function. Signed-off-by: Guillaume Knispel Cc: Alexander Viro Cc: Arjan van de Ven Cc: Thomas Gleixner Cc: Heiko Carstens Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

poll/select: initialize triggered field of struct poll_wqueues

2009-08-16T01:40:11Z

The triggered field of struct poll_wqueues introduced in commit 5f820f648c92a5ecc771a96b3c29aa6e90013bba ("poll: allow f_op->poll to sleep"). It was first set to 1 in pollwake() (now __pollwake() ), tested and later set to 0 in poll_schedule_timeout(), but not initialized before. As a result when the process needs to sleep, triggered was likely to be non-zero even if pollwake() is not called before the first poll_schedule_timeout(), meaning schedule_hrtimeout_range() would not be called and an extra loop calling all ->poll() would be done. This patch initialize triggered to 0 in poll_initwait() so the ->poll() are not called twice before the process goes to sleep when it needs to. Signed-off-by: Guillaume Knispel Acked-by: Thomas Gleixner Acked-by: Tejun Heo Cc: stable@kernel.org Signed-off-by: Linus Torvalds