From 661c715c3b0e9586ff0aaedbe73a2a6d596ddb50 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Tue, 30 Aug 2022 18:27:44 +0800 Subject: [PATCH] um: use fallback for random_get_entropy() instead of zero stable inclusion from stable-v5.10.119 commit a5092be129cf950aefcfd31789dba81f4d9337ac category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6BB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a5092be129cf950aefcfd31789dba81f4d9337ac -------------------------------- commit 9f13fb0cd11ed2327abff69f6501a2c124c88b5a upstream. In the event that random_get_entropy() can't access a cycle counter or similar, falling back to returning 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. This is accomplished by just including the asm-generic code like on other architectures, which means we can get rid of the empty stub function here. Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: Richard Weinberger Cc: Anton Ivanov Acked-by: Johannes Berg Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- arch/um/include/asm/timex.h | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/um/include/asm/timex.h b/arch/um/include/asm/timex.h index e392a9a5bc9b..9f27176adb26 100644 --- a/arch/um/include/asm/timex.h +++ b/arch/um/include/asm/timex.h @@ -2,13 +2,8 @@ #ifndef __UM_TIMEX_H #define __UM_TIMEX_H -typedef unsigned long cycles_t; - -static inline cycles_t get_cycles (void) -{ - return 0; -} - #define CLOCK_TICK_RATE (HZ) +#include + #endif -- GitLab