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authorAl Viro <viro@zeniv.linux.org.uk>2023-01-30 23:52:40 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2023-03-02 12:32:44 -0500
commitcaa82ae7ef52b7cf5f80a2b2fbcbdbcfd16426cc (patch)
treefe59f45376e19cd3bcaa3e6362ff9a4216bbe3f4 /arch
parente902e508c5b280488c62f119a05ad88f9f7eb1cb (diff)
openrisc: fix livelock in uaccess
openrisc equivalent of 26178ec11ef3 "x86: mm: consolidate VM_FAULT_RETRY handling" If e.g. get_user() triggers a page fault and a fatal signal is caught, we might end up with handle_mm_fault() returning VM_FAULT_RETRY and not doing anything to page tables. In such case we must *not* return to the faulting insn - that would repeat the entire thing without making any progress; what we need instead is to treat that as failed (user) memory access. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/openrisc/mm/fault.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index b4762d66e9ef..6734fee3134f 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -162,8 +162,11 @@ good_area:
fault = handle_mm_fault(vma, address, flags, regs);
- if (fault_signal_pending(fault, regs))
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
return;
+ }
/* The fault is fully completed (including releasing mmap lock) */
if (fault & VM_FAULT_COMPLETED)