summaryrefslogtreecommitdiff
path: root/arch/parisc/include
diff options
context:
space:
mode:
authorJohn David Anglin <dave.anglin@bell.net>2022-03-09 21:14:36 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-08 14:23:56 +0200
commitb3ea76bda7f7f84b2fb9e0b66fbd9f3e059458df (patch)
tree98658d07f483737253dc8d6dab813f55bdab1c3a /arch/parisc/include
parentc29642ba72f87c0a3d7449f7db5d6d76a7ed53c3 (diff)
parisc: Fix handling off probe non-access faults
[ Upstream commit e00b0a2ab8ec019c344e53bfc76e31c18bb587b7 ] Currently, the parisc kernel does not fully support non-access TLB fault handling for probe instructions. In the fast path, we set the target register to zero if it is not a shadowed register. The slow path is not implemented, so we call do_page_fault. The architecture indicates that non-access faults should not cause a page fault from disk. This change adds to code to provide non-access fault support for probe instructions. It also modifies the handling of faults on userspace so that if the address lies in a valid VMA and the access type matches that for the VMA, the probe target register is set to one. Otherwise, the target register is set to zero. This was done to make probe instructions more useful for userspace. Probe instructions are not very useful if they set the target register to zero whenever a page is not present in memory. Nominally, the purpose of the probe instruction is determine whether read or write access to a given address is allowed. This fixes a problem in function pointer comparison noticed in the glibc testsuite (stdio-common/tst-vfprintf-user-type). The same problem is likely in glibc (_dl_lookup_address). V2 adds flush and lpa instruction support to handle_nadtlb_fault. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/parisc/include')
-rw-r--r--arch/parisc/include/asm/traps.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/traps.h b/arch/parisc/include/asm/traps.h
index 8ecc1f0c0483..d0e090a2c000 100644
--- a/arch/parisc/include/asm/traps.h
+++ b/arch/parisc/include/asm/traps.h
@@ -17,6 +17,7 @@ void die_if_kernel(char *str, struct pt_regs *regs, long err);
const char *trap_name(unsigned long code);
void do_page_fault(struct pt_regs *regs, unsigned long code,
unsigned long address);
+int handle_nadtlb_fault(struct pt_regs *regs);
#endif
#endif