Pavel Kozlov ba5f2f952e ARC: atomics: Add compiler barrier to atomic operations... ... commit 42f51fb24f upstream. ... to avoid unwanted gcc optimizations SMP kernels fail to boot with commit 596ff4a09b ("cpumask: re-introduce constant-sized cpumask optimizations"). | | percpu: BUG: failure at mm/percpu.c:2981/pcpu_build_alloc_info()! | The write operation performed by the SCOND instruction in the atomic inline asm code is not properly passed to the compiler. The compiler cannot correctly optimize a nested loop that runs through the cpumask in the pcpu_build_alloc_info() function. Fix this by add a compiler barrier (memory clobber in inline asm). Apparently atomic ops used to have memory clobber implicitly via surrounding smp_mb(). However commit b64be68369 ("ARC: atomics: implement relaxed variants") removed the smp_mb() for the relaxed variants, but failed to add the explicit compiler barrier. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/135 Cc: <stable@vger.kernel.org> # v6.3+ Fixes: b64be68369 ("ARC: atomics: implement relaxed variants") Signed-off-by: Pavel Kozlov <pavel.kozlov@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org> [vgupta: tweaked the changelog and added Fixes tag] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-09-19 12:30:22 +02:00
..
boot	arc: dts: Harmonize EHCI/OHCI DT nodes name	2022-10-17 16:32:12 -07:00
configs	mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED	2023-05-26 19:01:47 +02:00
include	ARC: atomics: Add compiler barrier to atomic operations...	2023-09-19 12:30:22 +02:00
kernel	SMP cross-CPU function-call updates for v6.4:	2023-04-28 15:03:43 -07:00
lib	…
mm	asm-generic updates for 6.5	2023-07-06 10:06:04 -07:00
plat-axs10x	…
plat-hsdk	…
plat-sim	…
plat-tb10x	…
Kbuild	…
Kconfig	mm/fault: convert remaining simple cases to lock_mm_and_find_vma()	2023-06-24 14:12:58 -07:00
Kconfig.debug	…
Makefile	…