diff options
| -rw-r--r-- | arch/arm64/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 16 |
3 files changed, 14 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index e2f575dbdddd..c6fddb005dc2 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -107,6 +107,7 @@ struct thread_struct { struct fpsimd_state fpsimd_state; void *sve_state; /* SVE registers, if any */ unsigned int sve_vl; /* SVE vector length */ + unsigned int sve_vl_onexec; /* SVE vl after next exec */ unsigned long fault_address; /* fault info */ unsigned long fault_code; /* ESR_EL1 value */ struct debug_info debug; /* debugging */ diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 92b7b48576c8..eb431286bacd 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -95,6 +95,7 @@ void arch_release_task_struct(struct task_struct *tsk); #define TIF_SINGLESTEP 21 #define TIF_32BIT 22 /* 32bit process */ #define TIF_SVE 23 /* Scalable Vector Extension in use */ +#define TIF_SVE_VL_INHERIT 24 /* Inherit sve_vl_onexec across exec */ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 000b5f9215c6..c7531b85b303 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -111,6 +111,9 @@ */ static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state); +/* Default VL for tasks that don't set it explicitly: */ +static int sve_default_vl = SVE_VL_MIN; + /* * Call __sve_free() directly only if you know task can't be scheduled * or preempted. @@ -474,15 +477,20 @@ void fpsimd_flush_thread(void) * If a bug causes this to go wrong, we make some noise and * try to fudge thread.sve_vl to a safe value here. */ - vl = current->thread.sve_vl; - - if (vl == 0) - vl = SVE_VL_MIN; + vl = current->thread.sve_vl_onexec ? + current->thread.sve_vl_onexec : sve_default_vl; if (WARN_ON(!sve_vl_valid(vl))) vl = SVE_VL_MIN; current->thread.sve_vl = vl; + + /* + * If the task is not set to inherit, ensure that the vector + * length will be reset by a subsequent exec: + */ + if (!test_thread_flag(TIF_SVE_VL_INHERIT)) + current->thread.sve_vl_onexec = 0; } set_thread_flag(TIF_FOREIGN_FPSTATE); |