kernel.git/include/linux/kernel.h, branch linux-2.6.32.y

sched/x86: Fix overflow in cyc2ns_offset

2012-10-07T21:37:38Z

commit 9993bc635d01a6ee7f6b833b4ee65ce7c06350b1 upstream. When a machine boots up, the TSC generally gets reset. However, when kexec is used to boot into a kernel, the TSC value would be carried over from the previous kernel. The computation of cycns_offset in set_cyc2ns_scale is prone to an overflow, if the machine has been up more than 208 days prior to the kexec. The overflow happens when we multiply *scale, even though there is enough room to store the final answer. We fix this issue by decomposing tsc_now into the quotient and remainder of division by CYC2NS_SCALE_FACTOR and then performing the multiplication separately on the two components. Refactor code to share the calculation with the previous fix in __cycles_2_ns(). Signed-off-by: Salman Qazi Acked-by: John Stultz Acked-by: Peter Zijlstra Cc: Paul Turner Cc: john stultz Link: http://lkml.kernel.org/r/20120310004027.19291.88460.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar Cc: Mike Galbraith Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

printk_ratelimited(): fix uninitialized spinlock

2012-03-04T17:49:19Z

commit d8521fcc5e0ad3e79bbc4231bb20a6cdc2b50164 upstream. ratelimit_state initialization of printk_ratelimited() seems broken. This fixes it by using DEFINE_RATELIMIT_STATE() to initialize spinlock properly. Signed-off-by: OGAWA Hirofumi Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Sven-Haegar Koch Signed-off-by: Greg Kroah-Hartman

kernel.h: fix wrong usage of __ratelimit()

2012-03-04T17:49:19Z

commit bb1dc0bacb8ddd7ba6a5906c678a5a5a110cf695 upstream. When __ratelimit() returns 1 this means that we can go ahead. Signed-off-by: Yong Zhang Cc: Ingo Molnar Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

kernel.h: add printk_ratelimited and pr__rl

2012-01-25T21:53:24Z

commit 8a64f336bc1d4aa203b138d29d5a9c414a9fbb47 upstream. Add a printk_ratelimited statement expression macro that uses a per-call ratelimit_state so that multiple subsystems output messages are not suppressed by a global __ratelimit state. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: s/_rl/_ratelimited/g] Signed-off-by: Joe Perches Cc: Naohiro Ooiwa Cc: Ingo Molnar Cc: Hiroshi Shimamoto Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

warn about use of uninstalled kernel headers

2009-10-11T21:21:25Z

User applications frequently hit problems when they try to use the kernel headers directly, rather than the exported headers. This adds an explicit warning for this case, and points to a URL holding an explanation of why this is wrong and what to do about it. Signed-off-by: Arnd Bergmann Signed-off-by: Sam Ravnborg

Make sure the value in abs() does not get truncated if it is greater than 2^32

2009-09-23T14:39:30Z

abs() will truncate the input if is it outside the 2^32 range. Fix that by assuming `long' input. This might generate worse code in the common case. Signed-off-by: Rolf Eike Beer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

BUILD_BUG_ON(): fix it and a couple of bogus uses of it

2009-09-23T14:39:29Z

gcc permitting variable length arrays makes the current construct used for BUILD_BUG_ON() useless, as that doesn't produce any diagnostic if the controlling expression isn't really constant. Instead, this patch makes it so that a bit field gets used here. Consequently, those uses where the condition isn't really constant now also need fixing. Note that in the gfp.h, kmemcheck.h, and virtio_config.h cases MAYBE_BUILD_BUG_ON() really just serves documentation purposes - even if the expression is compile time constant (__builtin_constant_p() yields true), the array is still deemed of variable length by gcc, and hence the whole expression doesn't have the intended effect. [akpm@linux-foundation.org: make arch/sparc/include/asm/vio.h compile] [akpm@linux-foundation.org: more nonsensical assertions in tpm.c..] Signed-off-by: Jan Beulich Cc: Andi Kleen Cc: Rusty Russell Cc: Catalin Marinas Cc: "David S. Miller" Cc: Rajiv Andrade Cc: Mimi Zohar Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

printk_once(): use bool for boolean flag

2009-09-23T14:39:29Z

Using the type bool (instead of int) for the __print_once flag in the printk_once() macro matches the intent of the code better, and allows the compiler to generate smaller code; eg a typical callsite with gcc 4.3.3 on i386: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-6 (-6) function old new delta static.__print_once 4 1 -3 get_cpu_vendor 146 143 -3 Saving 6 bytes of object size per callsite by slightly improving the readability of the source seems like a win to me. Signed-off-by: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

printk: add printk_delay to make messages readable for some scenarios

2009-09-23T14:39:28Z

When syslog is not possible, at the same time there's no serial/net console available, it will be hard to read the printk messages. For example oops/panic/warning messages in shutdown phase. Add a printk delay feature, we can make each printk message delay some milliseconds. Setting the delay by proc/sysctl interface: /proc/sys/kernel/printk_delay The value range from 0 - 10000, default value is 0 [akpm@linux-foundation.org: fix a few things] Signed-off-by: Dave Young Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sched: Add a preempt count base offset to __might_sleep()

2009-07-18T13:51:42Z

Add a preempt count base offset to compare against the current preempt level count. It prepares to pull up the might_sleep check from cond_resched() to cond_resched_lock() and cond_resched_bh(). For these two helpers, we need to respectively ensure that once we'll unlock the given spinlock / reenable local softirqs, we will reach a sleepable state. Signed-off-by: Frederic Weisbecker [ Move and rename preempt_count_equals() ] Signed-off-by: Peter Zijlstra LKML-Reference: <1247725694-6082-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar