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+
1 parent f0d1cfa
Kbuild.platforms
# SPDX-License-Identifier: GPL-2.0
# All platforms listed in alphabetic order
platform-$(CONFIG_MIPS_ALCHEMY) += alchemy/
platform-$(CONFIG_AR7) += ar7/
platform-$(CONFIG_ATH25) += ath25/
platform-$(CONFIG_ATH79) += ath79/
platform-$(CONFIG_BCM47XX) += bcm47xx/
platform-$(CONFIG_BCM63XX) += bcm63xx/
platform-$(CONFIG_BMIPS_GENERIC) += bmips/
platform-$(CONFIG_CAVIUM_OCTEON_SOC) += cavium-octeon/
platform-$(CONFIG_MIPS_COBALT) += cobalt/
platform-$(CONFIG_MACH_DECSTATION) += dec/
platform-$(CONFIG_MIPS_GENERIC) += generic/
platform-$(CONFIG_MACH_JAZZ) += jazz/
platform-$(CONFIG_LANTIQ) += lantiq/
platform-$(CONFIG_MACH_LOONGSON2EF) += loongson2ef/
platform-$(CONFIG_MACH_LOONGSON32) += loongson32/
platform-$(CONFIG_MACH_LOONGSON64) += loongson64/
platform-$(CONFIG_MIPS_MALTA) += mti-malta/
platform-$(CONFIG_MACH_NINTENDO64) += n64/
platform-$(CONFIG_PIC32MZDA) += pic32/
platform-$(CONFIG_RALINK) += ralink/
platform-$(CONFIG_MIKROTIK_RB532) += rb532/
platform-$(CONFIG_SGI_IP22) += sgi-ip22/
platform-$(CONFIG_SGI_IP27) += sgi-ip27/
platform-$(CONFIG_SGI_IP28) += sgi-ip22/
platform-$(CONFIG_SGI_IP30) += sgi-ip30/
platform-$(CONFIG_SGI_IP32) += sgi-ip32/
platform-$(CONFIG_SIBYTE_BCM112X) += sibyte/
platform-$(CONFIG_SIBYTE_SB1250) += sibyte/
platform-$(CONFIG_SIBYTE_BCM1x55) += sibyte/
platform-$(CONFIG_SIBYTE_BCM1x80) += sibyte/
platform-$(CONFIG_SNI_RM) += sni/
platform-$(CONFIG_MACH_TX39XX) += txx9/
platform-$(CONFIG_MACH_TX49XX) += txx9/
platform-$(CONFIG_MACH_VR41XX) += vr41xx/
# include the platform specific files
include $(patsubst %/, $(srctree)/arch/mips/%/Platform, $(platform-y))
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