linux_dsm_epyc7002/arch/arm64
Anshuman Khandual a0509313d5 arm64/mm: Drop mmap_sem before calling __do_kernel_fault()
There is an inconsistency between down_read_trylock() success and failure
paths while dealing with kernel access for non exception table areas where
it calls __do_kernel_fault(). In case of failure it just bails out without
holding mmap_sem but when it succeeds it does so while holding mmap_sem.
Fix this inconsistency by just dropping mmap_sem in success path as well.

__do_kernel_fault() calls die_kernel_fault() which then calls show_pte().
show_pte() in this path might become bit more unreliable without holding
mmap_sem. But there are already instances [1] in do_page_fault() where
die_kernel_fault() gets called without holding mmap_sem. show_pte() can
be made more robust independently but in a later patch.

[1] Conditional block for (is_ttbr0_addr && is_el1_permission_fault)

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-04 15:26:18 +01:00
..
boot treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
configs ARM: SoC defconfig updates 2019-05-16 09:35:26 -07:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
include arm64/mm: Simplify protection flag creation for kernel huge mappings 2019-06-04 13:49:58 +01:00
kernel arm64: kernel: use aff3 instead of aff2 in comment 2019-06-04 14:51:01 +01:00
kvm arm64/fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use it 2019-06-04 13:17:30 +01:00
lib arm64: Makefile: Replace -pg with CC_FLAGS_FTRACE 2019-04-09 10:34:59 +01:00
mm arm64/mm: Drop mmap_sem before calling __do_kernel_fault() 2019-06-04 15:26:18 +01:00
net treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xen treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig arm64: mm: make CONFIG_ZONE_DMA32 configurable 2019-06-04 13:58:28 +01:00
Kconfig.debug treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.platforms treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile kasan, arm64: adjust shadow size for tag-based mode 2018-12-28 12:11:43 -08:00