From: Catalin Marinas <catalin.marinas@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>,
Richard Earnshaw <Richard.Earnshaw@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
Peter Collingbourne <pcc@google.com>,
linux-mm@kvack.org, linux-arch@vger.kernel.org
Subject: Re: [PATCH v2 10/19] arm64: mte: Handle synchronous and asynchronous tag check faults
Date: Thu, 27 Feb 2020 11:50:31 +0000 [thread overview]
Message-ID: <20200227115031.GC3281767@arrakis.emea.arm.com> (raw)
In-Reply-To: <20200226180526.3272848-11-catalin.marinas@arm.com>
On Wed, Feb 26, 2020 at 06:05:17PM +0000, Catalin Marinas wrote:
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index fc6488660f64..d4a378bc0a60 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -63,6 +63,7 @@ obj-$(CONFIG_CRASH_CORE) += crash_core.o
> obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o
> obj-$(CONFIG_ARM64_SSBD) += ssbd.o
> obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o
> +obj-$(CONFIG_ARM64_MTE) += mte.o
>
> obj-y += vdso/ probes/
> obj-$(CONFIG_COMPAT_VDSO) += vdso32/
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 9461d812ae27..9338b340e869 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
[...]
> @@ -738,6 +763,8 @@ work_pending:
> */
> ret_to_user:
> disable_daif
> + /* Check for asynchronous tag check faults in the uaccess routines */
> + check_mte_async_tcf x1, x2
> gic_prio_kentry_setup tmp=x3
> ldr x1, [tsk, #TSK_TI_FLAGS]
> and x2, x1, #_TIF_WORK_MASK
I got this wrong, check_mte_async expects the flags as the first
argument (one may experience weird behaviour with overriding the TIF
flags; thanks to Kevin for debugging). The diff below should fix it:
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 9338b340e869..6e7f315911e8 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -764,9 +764,9 @@ work_pending:
ret_to_user:
disable_daif
/* Check for asynchronous tag check faults in the uaccess routines */
- check_mte_async_tcf x1, x2
gic_prio_kentry_setup tmp=x3
ldr x1, [tsk, #TSK_TI_FLAGS]
+ check_mte_async_tcf x1, x2
and x2, x1, #_TIF_WORK_MASK
cbnz x2, work_pending
finish_ret_to_user:
next prev parent reply other threads:[~2020-02-27 11:50 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 18:05 [PATCH v2 00/19] arm64: Memory Tagging Extension user-space support Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 01/19] arm64: alternative: Allow alternative_insn to always issue the first instruction Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 02/19] arm64: mte: system register definitions Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 03/19] arm64: mte: CPU feature detection and initial sysreg configuration Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 04/19] arm64: mte: Use Normal Tagged attributes for the linear map Catalin Marinas
2020-03-05 16:21 ` Steven Price
2020-03-05 16:38 ` Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 05/19] arm64: mte: Assembler macros and default architecture for .S files Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 06/19] arm64: mte: Tags-aware clear_page() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 07/19] arm64: mte: Tags-aware copy_page() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 08/19] arm64: Tags-aware memcmp_pages() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 09/19] arm64: mte: Add specific SIGSEGV codes Catalin Marinas
2020-02-26 19:05 ` Eric W. Biederman
2020-02-26 19:26 ` Catalin Marinas
2020-02-26 22:33 ` kbuild test robot
2020-02-27 11:05 ` Catalin Marinas
2020-02-27 15:20 ` Eric W. Biederman
2020-02-26 18:05 ` [PATCH v2 10/19] arm64: mte: Handle synchronous and asynchronous tag check faults Catalin Marinas
2020-02-27 11:50 ` Catalin Marinas [this message]
2020-02-26 18:05 ` [PATCH v2 11/19] mm: Introduce arch_calc_vm_flag_bits() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 12/19] arm64: mte: Add PROT_MTE support to mmap() and mprotect() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 13/19] mm: Introduce arch_validate_flags() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 14/19] arm64: mte: Validate the PROT_MTE request via arch_validate_flags() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 15/19] mm: Allow arm64 mmap(PROT_MTE) on RAM-based files Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 16/19] arm64: mte: Allow user control of the tag check mode via prctl() Catalin Marinas
2020-03-09 13:53 ` Kevin Brodsky
2020-02-26 18:05 ` [PATCH v2 17/19] arm64: mte: Allow user control of the generated random tags " Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 18/19] arm64: mte: Kconfig entry Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 19/19] arm64: mte: Add Memory Tagging Extension documentation Catalin Marinas
2020-03-09 14:30 ` Kevin Brodsky
2020-03-11 22:17 ` Richard Henderson
2020-03-12 9:50 ` Catalin Marinas
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