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| author | Al Viro <viro@zeniv.linux.org.uk> | 2023-01-31 07:46:10 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2023-03-02 20:30:21 +0300 |
| commit | 0b92ed09cb9ffada29ca05510ef28252b6059d6d (patch) | |
| tree | b6c8a7a33d74b5e06b75e1f7022f83da37b3fa6b | |
| parent | d835eb3a57de50d16dd4a6b53f95dbc2bfa8ef48 (diff) | |
| download | linux-0b92ed09cb9ffada29ca05510ef28252b6059d6d.tar.xz | |
hexagon: fix livelock in uaccess
hexagon 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.
Acked-by: Brian Cain <bcain@quicinc.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | arch/hexagon/mm/vm_fault.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c index f73c7cbfe326..4b578d02fd01 100644 --- a/arch/hexagon/mm/vm_fault.c +++ b/arch/hexagon/mm/vm_fault.c @@ -93,8 +93,11 @@ 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) |