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| author | Anshuman Khandual <anshuman.khandual@arm.com> | 2021-06-15 15:02:58 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 16:56:07 +0200 |
| commit | bb5e089df7008e452ad96a169dac221246cc2644 (patch) | |
| tree | ce364bd8384f075f9bb02452fe7794724ff242fe | |
| parent | 8d6acfe80da165cfc9a6fadee7d73f8fd67a43ea (diff) | |
| download | kernel_replicant_linux-bb5e089df7008e452ad96a169dac221246cc2644.tar.gz kernel_replicant_linux-bb5e089df7008e452ad96a169dac221246cc2644.tar.bz2 kernel_replicant_linux-bb5e089df7008e452ad96a169dac221246cc2644.zip | |
arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
[ Upstream commit 9163f01130304fab1f74683d7d44632da7bda637 ]
When using CONFIG_ARM64_SW_TTBR0_PAN, a task's thread_info::ttbr0 must be
the TTBR0_EL1 value used to run userspace. With 52-bit PAs, the PA must be
packed into the TTBR using phys_to_ttbr(), but we forget to do this in some
of the SW PAN code. Thus, if the value is installed into TTBR0_EL1 (as may
happen in the uaccess routines), this could result in UNPREDICTABLE
behaviour.
Since hardware with 52-bit PA support almost certainly has HW PAN, which
will be used in preference, this shouldn't be a practical issue, but let's
fix this for consistency.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Fixes: 529c4b05a3cb ("arm64: handle 52-bit addresses in TTBR")
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1623749578-11231-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/mmu_context.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/setup.c | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index 68028de06d18..5a54a5ab5f92 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -192,9 +192,9 @@ static inline void update_saved_ttbr0(struct task_struct *tsk, return; if (mm == &init_mm) - ttbr = __pa_symbol(reserved_pg_dir); + ttbr = phys_to_ttbr(__pa_symbol(reserved_pg_dir)); else - ttbr = virt_to_phys(mm->pgd) | ASID(mm) << 48; + ttbr = phys_to_ttbr(virt_to_phys(mm->pgd)) | ASID(mm) << 48; WRITE_ONCE(task_thread_info(tsk)->ttbr0, ttbr); } diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index c28a9ec76b11..eb4b24652c10 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -366,7 +366,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) * faults in case uaccess_enable() is inadvertently called by the init * thread. */ - init_task.thread_info.ttbr0 = __pa_symbol(reserved_pg_dir); + init_task.thread_info.ttbr0 = phys_to_ttbr(__pa_symbol(reserved_pg_dir)); #endif if (boot_args[1] || boot_args[2] || boot_args[3]) { |