From: Russell King Date: Sun, 25 Oct 2009 14:12:27 +0000 (+0000) Subject: ARM: I-cache: flush executable mappings in flush_cache_range() X-Git-Tag: firefly_0821_release~9833^2~3964^2~5^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6060e8df517847bf445ebc61de7d4d9c7faae990;p=firefly-linux-kernel-4.4.55.git ARM: I-cache: flush executable mappings in flush_cache_range() Dirk Behme reported instability on ARM11 SMP (VIPT non-aliasing cache) caused by the dynamic linker changing protection on text pages to write GOT entries. The problem is due to an interaction between the write faulting code providing new anonymous pages which are incoherent with the I-cache due to write buffering, and the I-cache not having been invalidated. a4db94d plugs the hole with the data cache coherency. This patch provides the other half of the fix by flushing the I-cache in flush_cache_range() for VM_EXEC VMAs (which is what we have when the region is being made executable again.) This ensures that the I-cache will be up to date with the newly COW'd pages. Note: if users are writing instructions, then they still need to use the ARM sys_cacheflush API to ensure that the caches are correctly synchronized. Signed-off-by: Russell King --- diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index f8feb5d919fe..329594e760cd 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -66,10 +66,9 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned : : "r" (0) : "cc"); - __flush_icache_all(); } - if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged()) + if (vma->vm_flags & VM_EXEC) __flush_icache_all(); }