Revision 38860b2c8bb1b92f61396eb06a63adff916fc31d authored by John David Anglin on 08 November 2021, 21:48:16 UTC, committed by Helge Deller on 13 November 2021, 21:10:56 UTC
For years, there have been random segmentation faults in userspace on SMP PA-RISC machines. It occurred to me that this might be a problem in set_pte_at(). MIPS and some other architectures do cache flushes when installing PTEs with the present bit set. Here I have adapted the code in update_mmu_cache() to flush the kernel mapping when the kernel flush is deferred, or when the kernel mapping may alias with the user mapping. This simplifies calls to update_mmu_cache(). I also changed the barrier in set_pte() from a compiler barrier to a full memory barrier. I know this change is not sufficient to fix the problem. It might not be needed. I have had a few days of operation with 5.14.16 to 5.15.1 and haven't seen any random segmentation faults on rp3440 or c8000 so far. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@kernel.org # 5.12+
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File | Mode | Size |
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alchemy | ||
ar7 | ||
ath25 | ||
ath79 | ||
bcm47xx | ||
bcm63xx | ||
bmips | ||
boot | ||
cavium-octeon | ||
cobalt | ||
configs | ||
crypto | ||
dec | ||
fw | ||
generic | ||
include | ||
ingenic | ||
jazz | ||
kernel | ||
kvm | ||
lantiq | ||
lib | ||
loongson2ef | ||
loongson32 | ||
loongson64 | ||
math-emu | ||
mm | ||
mti-malta | ||
n64 | ||
net | ||
pci | ||
pic32 | ||
power | ||
ralink | ||
rb532 | ||
sgi-ip22 | ||
sgi-ip27 | ||
sgi-ip30 | ||
sgi-ip32 | ||
sibyte | ||
sni | ||
tools | ||
txx9 | ||
vdso | ||
vr41xx | ||
Kbuild | -rw-r--r-- | 644 bytes |
Kbuild.platforms | -rw-r--r-- | 1.6 KB |
Kconfig | -rw-r--r-- | 83.3 KB |
Kconfig.debug | -rw-r--r-- | 5.6 KB |
Makefile | -rw-r--r-- | 19.2 KB |
Makefile.postlink | -rw-r--r-- | 963 bytes |
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