From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
Anshuman Khandual <anshuman.khandual@arm.com>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 163/348] arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
Date: Mon, 12 Jul 2021 08:09:07 +0200 [thread overview]
Message-ID: <20210712060722.570590411@linuxfoundation.org> (raw)
In-Reply-To: <20210712060659.886176320@linuxfoundation.org>
From: Anshuman Khandual <anshuman.khandual@arm.com>
[ 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>
---
arch/arm64/include/asm/mmu_context.h | 4 ++--
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 1355205e5da5..fb564de90aa7 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -184,9 +184,9 @@ 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 203a0c31f260..f55f4a15a905 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -356,7 +356,7 @@ void __init 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
#ifdef CONFIG_VT
--
2.30.2
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prev parent reply other threads:[~2021-07-12 6:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210712060659.886176320@linuxfoundation.org>
2021-07-12 6:08 ` [PATCH 5.4 143/348] media: I2C: change RST to "RSET" to fix multiple build errors Greg Kroah-Hartman
2021-07-12 6:09 ` Greg Kroah-Hartman [this message]
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