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arm64/sve: Delay freeing memory in fpsimd_flush_thread()

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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 <bigeasy@linutronix.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220505163207.85751-2-bigeasy@linutronix.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Sebastian Andrzej Siewior 2022-05-05 18:32:05 +02:00 committed by Catalin Marinas
parent d158a0608e
commit a1259dd807
1 changed files with 15 additions and 2 deletions

17
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 fpsimd_flush_thread(void)
{ {
void *sve_state = NULL;
void *za_state = NULL;
if (!system_supports_fpsimd()) if (!system_supports_fpsimd())
return; return;
@ -1573,18 +1576,28 @@ void fpsimd_flush_thread(void)
if (system_supports_sve()) { if (system_supports_sve()) {
clear_thread_flag(TIF_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); fpsimd_flush_thread_vl(ARM64_VEC_SVE);
} }
if (system_supports_sme()) { if (system_supports_sme()) {
clear_thread_flag(TIF_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); fpsimd_flush_thread_vl(ARM64_VEC_SME);
current->thread.svcr = 0; current->thread.svcr = 0;
} }
put_cpu_fpsimd_context(); put_cpu_fpsimd_context();
kfree(sve_state);
kfree(za_state);
} }
/* /*