6.18-stable review patch. If anyone has any objections, please let me know.
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From: Akash Goel akash.goel@arm.com
[ Upstream commit 4492d54d59872bb72e119ff9f77969ab4d8a0e6b ]
This commit addresses a memleak issue of panthor_vma (or drm_gpuva) structure in Panthor driver, that can happen if the GPU page table update operation to map the pages fail. The issue is very unlikely to occur in practice.
v2: Add panthor_vm_op_ctx_return_vma() helper (Boris)
v3: Add WARN_ON_ONCE (Boris)
Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") Signed-off-by: Akash Goel akash.goel@arm.com Reviewed-by: Boris Brezillon boris.brezillon@collabora.com Reviewed-by: Steven Price steven.price@arm.com Signed-off-by: Steven Price steven.price@arm.com Link: https://patch.msgid.link/20251021081042.1377406-1-akash.goel@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 7870e7dbaa5d4..15961629872e1 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -1146,6 +1146,20 @@ static void panthor_vm_cleanup_op_ctx(struct panthor_vm_op_ctx *op_ctx, } }
+static void +panthor_vm_op_ctx_return_vma(struct panthor_vm_op_ctx *op_ctx, + struct panthor_vma *vma) +{ + for (u32 i = 0; i < ARRAY_SIZE(op_ctx->preallocated_vmas); i++) { + if (!op_ctx->preallocated_vmas[i]) { + op_ctx->preallocated_vmas[i] = vma; + return; + } + } + + WARN_ON_ONCE(1); +} + static struct panthor_vma * panthor_vm_op_ctx_get_vma(struct panthor_vm_op_ctx *op_ctx) { @@ -2085,8 +2099,10 @@ static int panthor_gpuva_sm_step_map(struct drm_gpuva_op *op, void *priv) ret = panthor_vm_map_pages(vm, op->map.va.addr, flags_to_prot(vma->flags), op_ctx->map.sgt, op->map.gem.offset, op->map.va.range); - if (ret) + if (ret) { + panthor_vm_op_ctx_return_vma(op_ctx, vma); return ret; + }
/* Ref owned by the mapping now, clear the obj field so we don't release the * pinning/obj ref behind GPUVA's back.