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| author | Marc Zyngier <Marc.Zyngier@arm.com> | 2013-11-04 20:14:58 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2013-11-05 09:33:57 +0000 |
| commit | 717321fcb58ed95169bf344ae47ac6098ba5dfbe (patch) | |
| tree | 288bb7a9d4e71c7161139cfad3181afc3d9d90b7 | |
| parent | 7ade67b5984d0a0434462fda733ab5138c63aae1 (diff) | |
| download | op-kernel-dev-717321fcb58ed95169bf344ae47ac6098ba5dfbe.zip op-kernel-dev-717321fcb58ed95169bf344ae47ac6098ba5dfbe.tar.gz | |
arm64: fix access to preempt_count from assembly code
preempt_count is defined as an int. Oddly enough, we access it
as a 64bit value. Things become interesting when running a BE
kernel, and looking at the current CPU number, which is stored
as an int next to preempt_count. Like in a per-cpu interrupt
handler, for example...
Using a 32bit access fixes the issue for good.
Cc: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/kernel/entry.S | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3881fd1..e116614 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -311,14 +311,14 @@ el1_irq: #endif #ifdef CONFIG_PREEMPT get_thread_info tsk - ldr x24, [tsk, #TI_PREEMPT] // get preempt count - add x0, x24, #1 // increment it - str x0, [tsk, #TI_PREEMPT] + ldr w24, [tsk, #TI_PREEMPT] // get preempt count + add w0, w24, #1 // increment it + str w0, [tsk, #TI_PREEMPT] #endif irq_handler #ifdef CONFIG_PREEMPT - str x24, [tsk, #TI_PREEMPT] // restore preempt count - cbnz x24, 1f // preempt count != 0 + str w24, [tsk, #TI_PREEMPT] // restore preempt count + cbnz w24, 1f // preempt count != 0 ldr x0, [tsk, #TI_FLAGS] // get flags tbz x0, #TIF_NEED_RESCHED, 1f // needs rescheduling? bl el1_preempt @@ -509,15 +509,15 @@ el0_irq_naked: #endif get_thread_info tsk #ifdef CONFIG_PREEMPT - ldr x24, [tsk, #TI_PREEMPT] // get preempt count - add x23, x24, #1 // increment it - str x23, [tsk, #TI_PREEMPT] + ldr w24, [tsk, #TI_PREEMPT] // get preempt count + add w23, w24, #1 // increment it + str w23, [tsk, #TI_PREEMPT] #endif irq_handler #ifdef CONFIG_PREEMPT - ldr x0, [tsk, #TI_PREEMPT] - str x24, [tsk, #TI_PREEMPT] - cmp x0, x23 + ldr w0, [tsk, #TI_PREEMPT] + str w24, [tsk, #TI_PREEMPT] + cmp w0, w23 b.eq 1f mov x1, #0 str x1, [x1] // BUG |
