kernel_samsung_sm7125

jenna

History

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
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boot	…
configs	…
crypto	…
ia32	aout: move setup_arg_pages() prior to reading/mapping the binary	13 years ago
include/asm	perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled	13 years ago
kernel	perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled	13 years ago
kvm	perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled	13 years ago
lguest	…
lib	x86: Derandom delay_tsc for 64 bit	13 years ago
math-emu	…
mm	x86: fix typo in recent find_vma_prev purge	13 years ago
net	…
oprofile	…
pci	x86/PCI: do not tie MSI MS-7253 use_crs quirk to BIOS version	13 years ago
platform	…
power	…
syscalls	…
tools	…
um	…
vdso	…
video	…
xen	…
.gitignore	…
Kbuild	…
Kconfig	…
Kconfig.cpu	…
Kconfig.debug	…
Makefile	…
Makefile.um	…
Makefile_32.cpu	…