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| author |   Mark Brown <broonie@kernel.org> | 2022-08-17 19:23:23 +0100 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2022-08-23 11:29:11 +0100 |
| commit | 826a4fdd2ada9e5923c58bdd168f31a42e958ffc (patch) | |
| tree | 99b8ee0f5ed1e99549981dd8346e9ffbf51658dc /arch/arm64/kernel/ptrace.c | |
| parent | arm64/signal: Flush FPSIMD register state when disabling streaming mode (diff) | |
| download | linux-dev-826a4fdd2ada9e5923c58bdd168f31a42e958ffc.tar.xz linux-dev-826a4fdd2ada9e5923c58bdd168f31a42e958ffc.zip | |
arm64/sme: Don't flush SVE register state when allocating SME storage
Currently when taking a SME access trap we allocate storage for the SVE
register state in order to be able to handle storage of streaming mode SVE.
Due to the original usage in a purely SVE context the SVE register state
allocation this also flushes the register state for SVE if storage was
already allocated but in the SME context this is not desirable. For a SME
access trap to be taken the task must not be in streaming mode so either
there already is SVE register state present for regular SVE mode which would
be corrupted or the task does not have TIF_SVE and the flush is redundant.
Fix this by adding a flag to sve_alloc() indicating if we are in a SVE
context and need to flush the state. Freshly allocated storage is always
zeroed either way.
Fixes: 8bd7f91c03d8 ("arm64/sme: Implement traps and syscall handling for SME")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220817182324.638214-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/ptrace.c')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 21da83187a60..eb7c08dfb834 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -882,7 +882,7 @@ static int sve_set_common(struct task_struct *target, * state and ensure there's storage. */ if (target->thread.svcr != old_svcr) - sve_alloc(target); + sve_alloc(target, true); } /* Registers: FPSIMD-only case */ @@ -912,7 +912,7 @@ static int sve_set_common(struct task_struct *target, goto out; } - sve_alloc(target); + sve_alloc(target, true); if (!target->thread.sve_state) { ret = -ENOMEM; clear_tsk_thread_flag(target, TIF_SVE); @@ -1082,7 +1082,7 @@ static int za_set(struct task_struct *target, /* Ensure there is some SVE storage for streaming mode */ if (!target->thread.sve_state) { - sve_alloc(target); + sve_alloc(target, false); if (!target->thread.sve_state) { clear_thread_flag(TIF_SME); ret = -ENOMEM; |