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authorRalf Baechle <ralf@linux-mips.org>2008-02-11 14:51:40 +0000
committerRalf Baechle <ralf@linux-mips.org>2008-02-19 17:01:31 +0000
commit2eaa7ec286db54cc1a864565ed9367966743bcbd (patch)
treeb764cafe754f065ea47e93c2e568836f76f3d339 /arch/mips/mm
parenteaf7943cc53d9688aa10267a226165356e956ec5 (diff)
[MIPS] Handle I-cache coherency in flush_cache_range()
So far flush_cache_range() did't consider the I-cache largely because it did rarely ever matter to real world code. This was working primarily because normally code and data are don't share the same pages - with the exception of MIPS16 code which uses address constants embedded between the code. The following sequence of events may break the code: o MIPS16 executable being loaded o dynamic linker relocates the address constants embedded into the code: o Uses mprotect(2) to make code pages PROT_READ|PROT_WRITE o Performs the actual relocations by writing to the pages which likely are COW. Because no PROT_EXEC is set I-cache coherence will not be considered. o Uses mprotect(2) to switch code pages back to PROT_READ|PROT_EXEC. This results in a call to flush_cache_range() which also does not consider I-caches. o => executing the page just having been relocated may now result in the I-cache getting refilled with stale data from memory. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
-rw-r--r--arch/mips/mm/c-r4k.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 53ec05267a9..2c4f7e11f0d 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -364,20 +364,23 @@ static inline int has_valid_asid(const struct mm_struct *mm)
static inline void local_r4k_flush_cache_range(void * args)
{
struct vm_area_struct *vma = args;
+ int exec = vma->vm_flags & VM_EXEC;
if (!(has_valid_asid(vma->vm_mm)))
return;
r4k_blast_dcache();
+ if (exec)
+ r4k_blast_icache();
}
static void r4k_flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
- if (!cpu_has_dc_aliases)
- return;
+ int exec = vma->vm_flags & VM_EXEC;
- r4k_on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1);
+ if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc))
+ r4k_on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1);
}
static inline void local_r4k_flush_cache_mm(void * args)