diff options
| author | Andrea Parri <parri.andrea@gmail.com> | 2024-01-31 15:49:33 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-02-15 08:04:11 -0800 |
| commit | d6cfd1770f20392d7009ae1fdb04733794514fa9 (patch) | |
| tree | c2cd9f5a579cd13931cc7e78536e4211aa91eae0 /arch/riscv/mm/context.c | |
| parent | 6613476e225e090cc9aad49be7fa504e290dd33d (diff) | |
membarrier: riscv: Add full memory barrier in switch_mm()
The membarrier system call requires a full memory barrier after storing
to rq->curr, before going back to user-space. The barrier is only
needed when switching between processes: the barrier is implied by
mmdrop() when switching from kernel to userspace, and it's not needed
when switching from userspace to kernel.
Rely on the feature/mechanism ARCH_HAS_MEMBARRIER_CALLBACKS and on the
primitive membarrier_arch_switch_mm(), already adopted by the PowerPC
architecture, to insert the required barrier.
Fixes: fab957c11efe2f ("RISC-V: Atomic and Locking Code")
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20240131144936.29190-2-parri.andrea@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/mm/context.c')
| -rw-r--r-- | arch/riscv/mm/context.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c index 217fd4de6134..ba8eb3944687 100644 --- a/arch/riscv/mm/context.c +++ b/arch/riscv/mm/context.c @@ -323,6 +323,8 @@ void switch_mm(struct mm_struct *prev, struct mm_struct *next, if (unlikely(prev == next)) return; + membarrier_arch_switch_mm(prev, next, task); + /* * Mark the current MM context as inactive, and the next as * active. This is at least used by the icache flushing |