From a1259dd807192917eb98603f8bc7b43f70cea5b9 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 5 May 2022 18:32:05 +0200 Subject: [PATCH] arm64/sve: Delay freeing memory in fpsimd_flush_thread() fpsimd_flush_thread() invokes kfree() via sve_free()+sme_free() within a preempt disabled section which is not working on -RT. Delay freeing of memory until preemption is enabled again. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20220505163207.85751-2-bigeasy@linutronix.de Signed-off-by: Catalin Marinas --- arch/arm64/kernel/fpsimd.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 64431bc62472..6e53badff8a6 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1562,6 +1562,9 @@ static void fpsimd_flush_thread_vl(enum vec_type type) void fpsimd_flush_thread(void) { + void *sve_state = NULL; + void *za_state = NULL; + if (!system_supports_fpsimd()) return; @@ -1573,18 +1576,28 @@ void fpsimd_flush_thread(void) if (system_supports_sve()) { clear_thread_flag(TIF_SVE); - sve_free(current); + + /* Defer kfree() while in atomic context */ + sve_state = current->thread.sve_state; + current->thread.sve_state = NULL; + fpsimd_flush_thread_vl(ARM64_VEC_SVE); } if (system_supports_sme()) { clear_thread_flag(TIF_SME); - sme_free(current); + + /* Defer kfree() while in atomic context */ + za_state = current->thread.za_state; + current->thread.za_state = NULL; + fpsimd_flush_thread_vl(ARM64_VEC_SME); current->thread.svcr = 0; } put_cpu_fpsimd_context(); + kfree(sve_state); + kfree(za_state); } /*