user/sven/linux.git/include/linux/compiler-gcc.h, branch v3.9.8

compiler-gcc.h: Add gcc-recommended GCC_VERSION macro

2013-02-22T01:22:15Z

Throughout compiler*.h, many version checks are made. These can be simplified by using the macro that gcc's documentation recommends. However, my primary reason for adding this is that I need bug-check macros that are enabled at certain gcc versions and it's cleaner to use this macro than the tradition method: #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ => 2) If you add patch level, it gets this ugly: #if __GNUC__ > 4 || (__GNUC__ == 4 && (__GNUC_MINOR__ > 2 || \ __GNUC_MINOR__ == 2 __GNUC_PATCHLEVEL__ >= 1)) As opposed to: #if GCC_VERSION >= 40201 While having separate headers for gcc 3 & 4 eliminates some of this verbosity, they can still be cleaned up by this. See also: http://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html Signed-off-by: Daniel Santos Acked-by: Borislav Petkov Acked-by: David Rientjes Cc: Andi Kleen Cc: Joe Perches Cc: Josh Triplett Cc: Paul Gortmaker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ftrace: Make all inline tags also include notrace

2012-06-18T13:47:00Z

Commit 5963e317b1e9d2a ("ftrace/x86: Do not change stacks in DEBUG when calling lockdep") prevented lockdep calls from the int3 breakpoint handler from reseting the stack if a function that was called was in the process of being converted for tracing and had a breakpoint on it. The idea is, before calling the lockdep code, do a load_idt() to the special IDT that kept the breakpoint stack from reseting. This worked well as a quick fix for this kernel release, until a certain config caused a lockup in the function tracer start up tests. Investigating it, I found that the load_idt that was used to prevent the int3 from changing stacks was itself being traced! Even though the config had CONFIG_OPTIMIZE_INLINING disabled, and all 'inline' tags were set to always inline, there were still cases that it did not inline! This was caused by CONFIG_PARAVIRT_GUEST, where it would add a pointer to the native_load_idt() which made that function to be traced. Commit 45959ee7aa645815a ("ftrace: Do not function trace inlined functions") only touched the 'inline' tags when CONFIG_OPMITIZE_INLINING was enabled. PARAVIRT_GUEST shows that this was not enough and we need to also mark always_inline with notrace as well. Reported-by: Fengguang Wu Tested-by: Fengguang Wu Signed-off-by: Steven Rostedt

include/ and checkpatch: prefer scanf to attribute__((format(scanf,...)

2012-03-23T23:58:36Z

It's equivalent to __printf, so prefer __scanf. Signed-off-by: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ftrace: Do not function trace inlined functions

2011-12-21T12:14:34Z

When gcc inlines a function, it does not mark it with the mcount prologue, which in turn means that inlined functions are not traced by the function tracer. But if CONFIG_OPTIMIZE_INLINING is set, then gcc is allowed not to inline a function that is marked inline. Depending on the options and the compiler, a function may or may not be traced by the function tracer, depending on whether gcc decides to inline a function or not. This has caused several problems in the pass becaues gcc is not always consistent with what it decides to inline between different gcc versions. Some places should not be traced (like paravirt native_* functions) and these are mostly marked as inline. When gcc decides not to inline the function, and if that function should not be traced, then the ftrace function tracer will suddenly break when it use to work fine. This becomes even harder to debug when different versions of gcc will not inline that function, making the same kernel and config work for some gcc versions and not work for others. By making all functions marked inline to not be traced will remove the ambiguity that gcc adds when it comes to tracing functions marked inline. All gcc versions will be consistent with what functions are traced and having volatile working code will be removed. Note, only the inline macro when CONFIG_OPTIMIZE_INLINING is set needs to have notrace added, as the attribute __always_inline will force the function to be inlined and then not traced. Signed-off-by: Steven Rostedt

sparse: define __must_be_array() for CHECKER

2011-05-25T15:39:46Z

commit c5e631cf65f ("ARRAY_SIZE: check for type") added __must_be_array(). But sparse can't parse this gcc extention. Now make C=2 makes following sparse errors a lot. kernel/futex.c:2699:25: error: No right hand side of '+'-expression Because __must_be_array() is used for ARRAY_SIZE() macro and it is used very widely. This patch fixes it. Signed-off-by: KOSAKI Motohiro Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/linux/compiler-gcc*.h: unify macro definitions

2011-03-23T00:44:10Z

Unify identical gcc3.x and gcc4.x macros. Signed-off-by: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/linux/compiler-gcc.h: use __same_type() in __must_be_array()

2010-08-10T03:45:04Z

We should use the __same_type() helper in __must_be_array(). Signed-off-by: Rusty Russell Reported-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

compiler-gcc.h: gcc-4.5 needs noclone and noinline on __naked functions

2010-06-29T22:29:31Z

A __naked function is defined in C but with a body completely implemented by asm(), including any prologue and epilogue. These asm() bodies expect standard calling conventions for parameter passing. Older GCCs implement that correctly, but 4.[56] currently do not, see GCC PR44290. In the Linux kernel this breaks ARM, causing most arch/arm/mm/copypage-*.c modules to get miscompiled, resulting in kernel crashes during bootup. Part of the kernel fix is to augment the __naked function attribute to also imply noinline and noclone. This patch implements that, and has been verified to fix boot failures with gcc-4.5 compiled 2.6.34 and 2.6.35-rc1 kernels. The patch is a no-op with older GCCs. Signed-off-by: Mikael Pettersson Signed-off-by: Khem Raj Cc: Russell King Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

compiler: Introduce __always_unused

2009-11-02T14:47:54Z

I wrote some code which is used as compile-time checker, and the code should be elided after compile. So I need to annotate the code as "always unused", compared to "maybe unused". Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Linus Torvalds LKML-Reference: <4AEE2CEC.8040206@cn.fujitsu.com> Signed-off-by: Ingo Molnar

[ARM] 5421/1: ftrace: fix crash due to tracing of __naked functions

2009-03-12T21:33:03Z

This is a fix for the following crash observed in 2.6.29-rc3: http://lkml.org/lkml/2009/1/29/150 On ARM it doesn't make sense to trace a naked function because then mcount is called without stack and frame pointer being set up and there is no chance to restore the lr register to the value before mcount was called. Reported-by: Matthias Kaehlcke Tested-by: Matthias Kaehlcke Cc: Abhishek Sagar Cc: Steven Rostedt Cc: Ingo Molnar Signed-off-by: Uwe Kleine-König Signed-off-by: Russell King