user/sven/linux.git/include/linux/kernel.h, branch v3.0.85

sched/x86: Fix overflow in cyc2ns_offset

2012-04-13T15:14:08Z

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

BUILD_BUG_ON_ZERO: fix sparse breakage

2011-06-16T03:04:00Z

BUILD_BUG_ON_ZERO and BUILD_BUG_ON_NULL must return values, even in the CHECKER case otherwise various users of it become syntactically invalid. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: add kstrto*_from_user()

2011-05-25T15:39:52Z

There is quite a lot of code which does copy_from_user() + strict_strto*() or simple_strto*() combo in slightly different ways. Before doing conversions all over tree, let's get final API correct. Enter kstrtoull_from_user() and friends. Typical code which uses them looks very simple: TYPE val; int rv; rv = kstrtoTYPE_from_user(buf, count, 0, &val); if (rv < 0) return rv; [use val] return count; There is a tiny semantic difference from the plain kstrto*() API -- the latter allows any amount of leading zeroes, while the former copies data into buffer on stack and thus allows leading zeroes as long as it fits into buffer. This shouldn't be a problem for typical usecase "echo 42 > /proc/x". The point is to make reading one integer from userspace _very_ simple and very bug free. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sparse: define dummy BUILD_BUG_ON definition for sparse

2011-05-25T15:39:46Z

BUILD_BUG_ON() causes a syntax error to detect coding errors. So it causes sparse to detect an error too. This reduces sparse's usefulness. This patch makes a dummy BUILD_BUG_ON() definition for sparse. Signed-off-by: KOSAKI Motohiro Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ftrace: Allow dynamically allocated function tracers

2011-05-18T19:29:51Z

Now that functions may be selected individually, it only makes sense that we should allow dynamically allocated trace structures to be traced. This will allow perf to allocate a ftrace_ops structure at runtime and use it to pick and choose which functions that structure will trace. Note, a dynamically allocated ftrace_ops will always be called indirectly instead of being called directly from the mcount in entry.S. This is because there's no safe way to prevent mcount from being preempted before calling the function, unless we modify every entry.S to do so (not likely). Thus, dynamically allocated functions will now be called by the ftrace_ops_list_func() that loops through the ops that are allocated if there are more than one op allocated at a time. This loop is protected with a preempt_disable. To determine if an ftrace_ops structure is allocated or not, a new util function was added to the kernel/extable.c called core_kernel_data(), which returns 1 if the address is between _sdata and _edata. Cc: Paul E. McKenney Signed-off-by: Steven Rostedt

kstrto*: converting strings to integers done (hopefully) right

2011-03-23T00:44:14Z

1. simple_strto*() do not contain overflow checks and crufty, libc way to indicate failure. 2. strict_strto*() also do not have overflow checks but the name and comments pretend they do. 3. Both families have only "long long" and "long" variants, but users want strtou8() 4. Both "simple" and "strict" prefixes are wrong: Simple doesn't exactly say what's so simple, strict should not exist because conversion should be strict by default. The solution is to use "k" prefix and add convertors for more types. Enter kstrtoull() kstrtoll() kstrtoul() kstrtol() kstrtouint() kstrtoint() kstrtou64() kstrtos64() kstrtou32() kstrtos32() kstrtou16() kstrtos16() kstrtou8() kstrtos8() Include runtime testsuite (somewhat incomplete) as well. strict_strto*() become deprecated, stubbed to kstrto*() and eventually will be removed altogether. Use kstrto*() in code today! Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if they'll be unused at runtime. This is temporarily solution, because I don't want to hardcode list of archs where these functions aren't needed. Current solution with sizeof() and __alignof__ at least always works. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel.h: fix kernel-doc warning

2011-01-31T22:23:22Z

Fix kernel-doc warning in kernel.h from commit 7ef88ad56145 ("BUILD_BUG_ON: make it handle more cases"): Warning(include/linux/kernel.h:605): No description found for parameter 'condition' Warning(include/linux/kernel.h:605): Excess function parameter 'cond' description in 'BUILD_BUG_ON' Signed-off-by: Randy Dunlap Signed-off-by: Linus Torvalds

Remove MAYBE_BUILD_BUG_ON

2011-01-24T04:15:11Z

Now BUILD_BUG_ON() can handle optimizable constants, we don't need MAYBE_BUILD_BUG_ON any more. Signed-off-by: Rusty Russell

BUILD_BUG_ON: make it handle more cases

2011-01-24T04:15:10Z

BUILD_BUG_ON used to use the optimizer to do code elimination or fail at link time; it was changed to first the size of a negative array (a nicer compile time error), then (in 8c87df457cb58fe75b9b893007917cf8095660a0) to a bitfield. This forced us to change some non-constant cases to MAYBE_BUILD_BUG_ON(); as Jan points out in that commit, it didn't work as intended anyway. bitfields: needs a literal constant at parse time, and can't be put under "if (__builtin_constant_p(x))" for example. negative array: can handle anything, but if the compiler can't tell it's a constant, silently has no effect. link time: breaks link if the compiler can't determine the value, but the linker output is not usually as informative as a compiler error. If we use the negative-array-size method *and* the link time trick, we get the ability to use BUILD_BUG_ON() under __builtin_constant_p() branches, and maximal ability for the compiler to detect errors at build time. We also document it thoroughly. Signed-off-by: Rusty Russell Cc: Jan Beulich Acked-by: Hollis Blanchard

lockdep: Move early boot local IRQ enable/disable status to init/main.c

2011-01-20T12:32:33Z

During early boot, local IRQ is disabled until IRQ subsystem is properly initialized. During this time, no one should enable local IRQ and some operations which usually are not allowed with IRQ disabled, e.g. operations which might sleep or require communications with other processors, are allowed. lockdep tracked this with early_boot_irqs_off/on() callbacks. As other subsystems need this information too, move it to init/main.c and make it generally available. While at it, toggle the boolean to early_boot_irqs_disabled instead of enabled so that it can be initialized with %false and %true indicates the exceptional condition. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Acked-by: Pekka Enberg Cc: Linus Torvalds LKML-Reference: <20110120110635.GB6036@htj.dyndns.org> Signed-off-by: Ingo Molnar