linux/include/asm-generic
Mathieu Desnoyers 6549864629 tracepoints: Fix section alignment using pointer array
Make the tracepoints more robust, making them solid enough to handle compiler
changes by not relying on anything based on compiler-specific behavior with
respect to structure alignment. Implement an approach proposed by David Miller:
use an array of const pointers to refer to the individual structures, and export
this pointer array through the linker script rather than the structures per se.
It will consume 32 extra bytes per tracepoint (24 for structure padding and 8
for the pointers), but are less likely to break due to compiler changes.

History:

commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
added the aligned(32) type and variable attribute to the tracepoint structures
to deal with gcc happily aligning statically defined structures on 32-byte
multiples.

One attempt was to use a 8-byte alignment for tracepoint structures by applying
both the variable and type attribute to tracepoint structures definitions and
declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5.

The reason is that the "aligned" attribute only specify the _minimum_ alignment
for a structure, leaving both the compiler and the linker free to align on
larger multiples. Because tracepoint.c expects the structures to be placed as an
array within each section, up-alignment cause NULL-pointer exceptions due to the
extra unexpected padding.

(this patch applies on top of -tip)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <20110126222622.GA10794@Krystal>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-03 09:28:46 -05:00
..
bitops bitops: remove duplicated extern declarations 2010-10-09 21:51:45 +02:00
4level-fixup.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
atomic64.h lib: Provide generic atomic64_t implementation 2009-06-15 13:27:38 +10:00
atomic-long.h asm-generic: merge branch 'master' of torvalds/linux-2.6 2009-06-12 11:32:58 +02:00
atomic.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 2010-10-22 11:17:06 -07:00
audit_change_attr.h audit: make link()/linkat() match "attribute change" predicate 2010-10-30 08:45:43 -04:00
audit_dir_write.h
audit_read.h
audit_signal.h [PATCH] add SIGNAL syscall class (v3) 2007-05-11 05:38:25 -04:00
audit_write.h [PATCH] asm/generic: fix bug - kernel fails to build when enable some common audit code on Blackfin 2008-12-09 02:27:39 -05:00
auxvec.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
bitops.h asm-generic: make bitops.h usable 2009-06-11 21:02:31 +02:00
bitsperlong.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
bug.h panic: Allow warnings to set different taint flags 2010-05-19 08:36:48 +01:00
bugs.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
cache.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
cacheflush.h block: add helpers to run flush_dcache_page() against a bio and a request's pages 2009-11-26 09:16:19 +01:00
checksum.h add generic lib/checksum.c 2009-06-11 21:02:51 +02:00
cmpxchg-local.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
cmpxchg.h Add cmpxchg_local to asm-generic for per cpu atomic operations 2008-02-07 08:42:30 -08:00
cputime.h taskstats: use real microsecond granularity for CPU times 2010-10-27 18:03:17 -07:00
current.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
delay.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
device.h Driver Core: Add platform device arch data V3 2009-07-22 00:28:38 +02:00
div64.h rename div64_64 to div64_u64 2008-05-01 08:03:58 -07:00
dma-coherent.h generic: per-device coherent dma allocator 2008-06-30 12:51:05 +02:00
dma-mapping-broken.h dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
dma-mapping-common.h dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops 2010-05-27 09:12:52 -07:00
dma.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
emergency-restart.h
errno-base.h
errno.h cfg80211: add rfkill support 2009-06-03 14:06:14 -04:00
fb.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
fcntl.h asm-generic: fcntl: make exported headers use strict posix types 2010-10-09 21:51:43 +02:00
futex.h remove __KERNEL__ tests of unexported headers under asm-generic/ 2008-04-30 08:29:54 -07:00
getorder.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
gpio.h Revert "gpiolib: annotate gpio-intialization with __must_check" 2011-01-13 17:26:46 -08:00
hardirq.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
hw_irq.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
ide_iops.h
int-l64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
int-ll64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
io.h asm-generic/io.h: add reads[bwl]/writes[bwl] helpers 2011-01-10 07:18:03 -05:00
ioctl.h Make ioctl.h compatible with userland 2008-08-12 16:07:31 -07:00
ioctls.h TTY: Add tty ioctl to figure device node of the system console. 2010-12-16 16:18:28 -08:00
iomap.h generic: add ioremap_wc() interface wrapper 2008-04-24 23:40:47 +02:00
ipcbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
irq_regs.h core: Replace __get_cpu_var with __this_cpu_read if not used for an address. 2010-12-17 15:07:19 +01:00
irq.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
irqflags.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
Kbuild include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
Kbuild.asm include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
kdebug.h asm-generic: kdebug.h: Checkpatch cleanup 2010-10-09 21:51:44 +02:00
kmap_types.h include/asm-generic/kmap_types.h: add helpful reminder 2010-05-25 08:07:03 -07:00
libata-portmap.h libata-portmap: Remove unused definitions 2007-10-12 14:55:37 -04:00
linkage.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
local64.h arch: Implement local64_t 2010-06-09 11:12:36 +02:00
local.h local_t: Remove cpu_local_xx macros 2010-01-05 15:34:49 +09:00
memory_model.h tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
mm_hooks.h
mman-common.h thp: mm: define MADV_NOHUGEPAGE 2011-01-13 17:32:47 -08:00
mman.h mm: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions 2009-09-22 07:17:41 -07:00
mmu_context.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
mmu.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
module.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
msgbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
mutex-dec.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex-null.h
mutex-xchg.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
page.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
param.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
parport.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
pci-dma-compat.h dma-mapping: pci: move pci_set_dma_mask and pci_set_consistent_dma_mask to pci-dma-compat.h 2010-03-12 15:52:42 -08:00
pci.h PCI: remove pcibios_scan_all_fns() 2009-09-09 13:29:18 -07:00
percpu.h percpu: Optimize __get_cpu_var() 2010-09-10 10:56:51 +02:00
pgalloc.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
pgtable-nopmd.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable-nopud.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable.h fix non-x86 build failure in pmdp_get_and_clear 2011-01-16 15:05:44 -08:00
poll.h Consolidate asm/poll.h 2007-05-11 08:29:34 -07:00
posix_types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
resource.h sched: SCHED_FIFO/SCHED_RR watchdog timer 2008-01-25 21:08:27 +01:00
rtc.h asm-generic: make get_rtc_time overridable 2009-06-11 21:02:18 +02:00
scatterlist.h asm-generic: remove ARCH_HAS_SG_CHAIN in scatterlist.h 2010-05-27 09:12:54 -07:00
sections.h asm/sections: add text/data checking functions for arches to override 2009-09-23 07:39:30 -07:00
segment.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
sembuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
serial.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
setup.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
shmbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
shmparam.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
siginfo.h HWPOISON: Add new SIGBUS error codes for hardware poison signals 2009-09-16 11:50:06 +02:00
signal-defs.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
signal.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
socket.h net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
sockios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
spinlock.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
stat.h asm-generic/stat.h: support 64-bit file time_t for stat() 2010-11-01 15:31:29 -04:00
statfs.h add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
string.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
swab.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
syscall.h asm-generic: syscall_get_nr returns int 2009-09-22 19:56:50 -07:00
syscalls.h Fix the declaration of sys_execve() in asm-generic/syscalls.h 2010-08-18 12:12:38 -07:00
system.h asm-generic: cmpxchg does not handle non-long arguments 2010-10-09 21:51:27 +02:00
termbits.h tty: Add EXTPROC support for LINEMODE 2010-08-10 13:47:39 -07:00
termios-base.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
termios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
timex.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
tlb.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
tlbflush.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
topology.h topology: alternate fix for ia64 tiger_defconfig build breakage 2010-08-09 20:44:57 -07:00
types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
uaccess-unaligned.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
uaccess.h asm-generic: uaccess: fix up local access_ok() usage 2009-06-19 14:58:08 +02:00
ucontext.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
unaligned.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
unistd.h Add fanotify syscalls to <asm-generic/unistd.h>. 2010-08-13 08:08:37 -04:00
user.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
vga.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
vmlinux.lds.h tracepoints: Fix section alignment using pointer array 2011-02-03 09:28:46 -05:00
xor.h