From ea3d28ec31d64cd059683947746ac71c8a90a1f9 Mon Sep 17 00:00:00 2001 From: Harald Seiler Date: Thu, 5 Jan 2023 01:08:47 +0100 Subject: [PATCH] Revert "time: add weak annotation to timer_read_counter declaration" This reverts commit 65ba7add0d609bbd035b8d42fafdaf428ac24751. A weak extern is a nasty sight to behold: If the symbol is never defined, on ARM, the linker will replace the function call with a NOP. This behavior isn't well documented but there are at least some hints to it [1]. When timer_read_counter() is not defined, this obviously does the wrong thing here and it does so silently. The consequence is that a board without timer_read_counter() will sleep for random amounts and generally have erratic get_ticks() values. Drop the __weak annotation of the extern so a linker error is raised when timer_read_counter() is not defined. This is okay, the original reason for the reverted change - breaking the sandbox build - no longer applies. Final sidenote: This was the only weak extern in the entire tree at this time as far as I can tell. I guess we should avoid introduction of them again as they are obviously a very big footgun. [1]: https://stackoverflow.com/questions/31203402/gcc-behavior-for-unresolved-weak-functions Fixes: 65ba7add0d60 ("time: add weak annotation to timer_read_counter declaration") Reported-by: Serge Bazanski Signed-off-by: Harald Seiler --- lib/time.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/time.c b/lib/time.c index 82350260ea..0c95d12f61 100644 --- a/lib/time.c +++ b/lib/time.c @@ -63,7 +63,7 @@ ulong timer_get_boot_us(void) } #else -extern unsigned long __weak timer_read_counter(void); +extern unsigned long timer_read_counter(void); #endif #if CONFIG_IS_ENABLED(TIMER) -- 2.39.5