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| author | Al Viro <viro@zeniv.linux.org.uk> | 2023-01-30 23:47:28 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2023-03-02 12:32:27 -0500 |
| commit | d088af1e221c32bd67825c5dccf664f699e827b4 (patch) | |
| tree | be718bd73e7d461089e86dc50f08e63f9c029c9d | |
| parent | 79c54c97c7735e09f9e2193a713f30e56eec00dc (diff) | |
| download | iio-d088af1e221c32bd67825c5dccf664f699e827b4.tar.gz | |
ia64: fix livelock in uaccess
ia64 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>
| -rw-r--r-- | arch/ia64/mm/fault.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index ef78c2d66cdde2..85c4d9ac8686d8 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -136,8 +136,11 @@ retry: */ 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) |