From: vladimir.murzin@arm.com (Vladimir Murzin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: V7M: Preserve registers across switch from Thread to Handler mode
Date: Thu, 30 Mar 2017 09:09:51 +0100 [thread overview]
Message-ID: <1490861391-35484-2-git-send-email-vladimir.murzin@arm.com> (raw)
In-Reply-To: <1490861391-35484-1-git-send-email-vladimir.murzin@arm.com>
According to ARMv7 ARM, when exception is taken content of r0-r3, r12
is unknown (see ExceptionTaken() pseudocode). Even though existent
implementations keep these register unchanged, preserve them to be in
line with architecture.
Reported-by: Dobromir Stefanov <dobromir.stefanov@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
arch/arm/mm/proc-v7m.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
index 5049777..47a5acc 100644
--- a/arch/arm/mm/proc-v7m.S
+++ b/arch/arm/mm/proc-v7m.S
@@ -135,9 +135,11 @@ __v7m_setup_cont:
dsb
mov r6, lr @ save LR
ldr sp, =init_thread_union + THREAD_START_SP
+ stmia sp, {r0-r3, r12}
cpsie i
svc #0
1: cpsid i
+ ldmia sp, {r0-r3, r12}
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
mov lr, r6 @ restore LR
--
1.9.1
next prev parent reply other threads:[~2017-03-30 8:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-30 8:09 [PATCH] ARM: V7M: Do not corrupt vector table around v7m_invalidate_l1 call Vladimir Murzin
2017-03-30 8:09 ` Vladimir Murzin [this message]
2017-04-18 12:54 ` [PATCH] ARM: V7M: Preserve registers across switch from Thread to Handler mode Vladimir Murzin
2017-04-18 12:53 ` [PATCH] ARM: V7M: Do not corrupt vector table around v7m_invalidate_l1 call Vladimir Murzin
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