You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

Thomas Gleixner a7f4255f90 x86: Derandom delay_tsc for 64 bit ... Commit f0fbf0abc0 ("x86: integrate delay functions") converted delay_tsc() into a random delay generator for 64 bit. The reason is that it merged the mostly identical versions of delay_32.c and delay_64.c. Though the subtle difference of the result was: static void delay_tsc(unsigned long loops) { - unsigned bclock, now; + unsigned long bclock, now; Now the function uses rdtscl() which returns the lower 32bit of the TSC. On 32bit that's not problematic as unsigned long is 32bit. On 64 bit this fails when the lower 32bit are close to wrap around when bclock is read, because the following check if ((now - bclock) >= loops) break; evaluated to true on 64bit for e.g. bclock = 0xffffffff and now = 0 because the unsigned long (now - bclock) of these values results in 0xffffffff00000001 which is definitely larger than the loops value. That explains Tvortkos observation: "Because I am seeing udelay(500) (_occasionally_) being short, and that by delaying for some duration between 0us (yep) and 491us." Make those variables explicitely u32 again, so this works for both 32 and 64 bit. Reported-by: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # >= 2.6.27 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		13 years ago
..
alpha	alpha: fix 32/64-bit bug in futex support	13 years ago
arm	IOMMU fixes for Linux v3.3-rc6	13 years ago
avr32	avr32: select generic atomic64_t support	13 years ago
blackfin	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	13 years ago
c6x	C6X: fix KSTK_EIP and KSTK_ESP macros	13 years ago
cris	lib: use generic pci_iomap on all architectures	13 years ago
frv	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	13 years ago
h8300	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	13 years ago
hexagon	…
ia64	Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux	13 years ago
m32r	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	13 years ago
m68k	m68k: Do not set global share for non-kernel shared pages	13 years ago
microblaze	Revert "microblaze: Add topology init"	13 years ago
mips	MIPS: traps.c: Fix typo	13 years ago
mn10300	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	13 years ago
openrisc	openrisc: Fix up audit_syscall_[entry|exit]() usage	13 years ago
parisc	[PARISC] don't unconditionally override CROSS_COMPILE for 64 bit.	13 years ago
powerpc	powerpc: Fix various issues with return to userspace	13 years ago
s390	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux	13 years ago
score	score: fix off-by-one index into syscall table	13 years ago
sh	SuperH fixes for 3.3-rc5	13 years ago
sparc	lib: Fix multiple definitions of clz_tab	13 years ago
tile	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	13 years ago
um	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit	13 years ago
unicore32	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	13 years ago
x86	x86: Derandom delay_tsc for 64 bit	13 years ago
xtensa	xtensa: fix memscan()	13 years ago
.gitignore	…
Kconfig	mm,x86,um: move CMPXCHG_DOUBLE config option	13 years ago