diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2023-01-31 07:50:22 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2023-03-02 20:32:31 +0300 |
| commit | a1179ac743e8f2044b67848b5109614619b65366 (patch) | |
| tree | 989ff8dc3f862c17d15a4df3ff631773df95612e /arch | |
| parent | d088af1e221c32bd67825c5dccf664f699e827b4 (diff) | |
| download | linux-a1179ac743e8f2044b67848b5109614619b65366.tar.xz | |
microblaze: fix livelock in uaccess
microblaze 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/microblaze/mm/fault.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c index 5c40c3ebe52f..687714db6f4d 100644 --- a/arch/microblaze/mm/fault.c +++ b/arch/microblaze/mm/fault.c @@ -219,8 +219,11 @@ 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)) + bad_page_fault(regs, address, SIGBUS); return; + } /* The fault is fully completed (including releasing mmap lock) */ if (fault & VM_FAULT_COMPLETED) |