diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2024-12-12 11:18:47 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-12-19 20:23:53 +0300 |
| commit | 92b6919d7fb29691a8bc5aca49044056683542ca (patch) | |
| tree | b644dad8b98269defb42840a4236e3280b42d39a | |
| parent | 9d86c3c974348eb4220b637fae1a2466232078b7 (diff) | |
| download | linux-92b6919d7fb29691a8bc5aca49044056683542ca.tar.xz | |
arm64: Kconfig: force ARM64_PAN=y when enabling TTBR0 sw PAN
There are a couple of instances of Kconfig constraints where PAN must be
enabled too if TTBR0 sw PAN is enabled, primarily to avoid dealing with
the modified TTBR0_EL1 sysreg format that is used when 52-bit physical
addressing and/or CnP are enabled (support for either implies support
for hardware PAN as well, which will supersede PAN emulation if both are
available)
Let's simplify this, and always enable ARM64_PAN when enabling TTBR0 sw
PAN. This decouples the PAN configuration from the VA size selection,
permitting us to simplify the latter in subsequent patches. (Note that
PAN and TTBR0 sw PAN can still be disabled after this patch, but not
independently)
To avoid a convoluted circular Kconfig dependency involving KCSAN, make
ARM64_MTE select ARM64_PAN too, instead of depending on it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241212081841.2168124-13-ardb+git@google.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/Kconfig | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 100570a048c5..c1ca21adddc1 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1379,7 +1379,6 @@ config ARM64_VA_BITS_48 config ARM64_VA_BITS_52 bool "52-bit" - depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN help Enable 52-bit virtual addressing for userspace when explicitly requested via a hint to mmap(). The kernel will also use 52-bit @@ -1431,7 +1430,6 @@ config ARM64_PA_BITS_48 config ARM64_PA_BITS_52 bool "52-bit" depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 - depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN help Enable support for a 52-bit physical address space, introduced as part of the ARMv8.2-LPA extension. @@ -1681,6 +1679,7 @@ config RODATA_FULL_DEFAULT_ENABLED config ARM64_SW_TTBR0_PAN bool "Emulate Privileged Access Never using TTBR0_EL1 switching" depends on !KCSAN + select ARM64_PAN help Enabling this option prevents the kernel from accessing user-space memory directly by pointing TTBR0_EL1 to a reserved @@ -1937,7 +1936,6 @@ config ARM64_RAS_EXTN config ARM64_CNP bool "Enable support for Common Not Private (CNP) translations" default y - depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN help Common Not Private (CNP) allows translation table entries to be shared between different PEs in the same inner shareable @@ -2132,7 +2130,7 @@ config ARM64_MTE depends on AS_HAS_ARMV8_5 depends on AS_HAS_LSE_ATOMICS # Required for tag checking in the uaccess routines - depends on ARM64_PAN + select ARM64_PAN select ARCH_HAS_SUBPAGE_FAULTS select ARCH_USES_HIGH_VMA_FLAGS select ARCH_USES_PG_ARCH_2 |