49 lines
1.4 KiB
Diff
49 lines
1.4 KiB
Diff
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Wed, 28 Jun 2023 09:36:10 +0200
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Subject: [PATCH 3/4] ARM: vfp: Use vfp_lock() in vfp_support_entry().
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.11/older/patches-6.11-rt7.tar.xz
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vfp_entry() is invoked from exception handler and is fully preemptible.
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It uses local_bh_disable() to remain uninterrupted while checking the
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VFP state.
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This is not working on PREEMPT_RT because local_bh_disable()
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synchronizes the relevant section but the context remains fully
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preemptible.
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Use vfp_lock() for uninterrupted access.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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arch/arm/vfp/vfpmodule.c | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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--- a/arch/arm/vfp/vfpmodule.c
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+++ b/arch/arm/vfp/vfpmodule.c
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@@ -708,7 +708,7 @@ static int vfp_support_entry(struct pt_r
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if (!user_mode(regs))
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return vfp_kmode_exception(regs, trigger);
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- local_bh_disable();
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+ vfp_lock();
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fpexc = fmrx(FPEXC);
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/*
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@@ -787,7 +787,7 @@ static int vfp_support_entry(struct pt_r
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if (!(fpscr & FPSCR_IXE)) {
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if (!(fpscr & FPSCR_LENGTH_MASK)) {
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pr_debug("not VFP\n");
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- local_bh_enable();
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+ vfp_unlock();
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return -ENOEXEC;
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}
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fpexc |= FPEXC_DEX;
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@@ -797,7 +797,7 @@ bounce: regs->ARM_pc += 4;
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VFP_bounce(trigger, fpexc, regs);
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}
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- local_bh_enable();
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+ vfp_unlock();
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return 0;
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}
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