6.18-stable review patch. If anyone has any objections, please let me know.
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From: Mark Brown broonie@kernel.org
commit 98a97bf41528ef738b06eb07ec2b2eb1cfde6ce6 upstream.
When we exec a new task we forget to flush the set of locked GCS mode bits. Since we do flush the rest of the state this means that if GCS is locked the new task will be unable to enable GCS, it will be locked as being disabled. Add the expected flush.
Fixes: fc84bc5378a8 ("arm64/gcs: Context switch GCS state for EL0") Cc: stable@vger.kernel.org # 6.13.x Reported-by: Yury Khrustalev Yury.Khrustalev@arm.com Signed-off-by: Mark Brown broonie@kernel.org Tested-by: Yury Khrustalev yury.khrustalev@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/process.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -292,6 +292,7 @@ static void flush_gcs(void) current->thread.gcs_base = 0; current->thread.gcs_size = 0; current->thread.gcs_el0_mode = 0; + current->thread.gcs_el0_locked = 0; write_sysreg_s(GCSCRE0_EL1_nTR, SYS_GCSCRE0_EL1); write_sysreg_s(0, SYS_GCSPR_EL0); }