[PATCH] radeon: use kvcalloc for relocs and chunks

From: Chen Li <chenli@uniontech.com>
To: amd-gfx@lists.freedesktop.org
Cc: "Alex Deucher" <alexander.deucher@amd.com>,
	"\"Christian König\"" <christian.koenig@amd.com>
Subject: [PATCH] radeon: use kvcalloc for relocs and chunks
Date: Wed, 17 Mar 2021 14:22:22 +0800	[thread overview]
Message-ID: <87czvyz4dd.wl-chenli@uniontech.com> (raw)


kvmalloc_array + __GFP_ZERO is the same with kvcalloc.

As for p->chunks, it will be used in:
```
if (ib_chunk->kdata)
		memcpy(parser->ib.ptr, ib_chunk->kdata, ib_chunk->length_dw * 4);
```

If chunks doesn't zero out with __GFP_ZERO, it may point to somewhere else, e.g.,
```
Unable to handle kernel paging request at virtual address 0000000000010000
...
pc is at memcpy+0x84/0x250
ra is at radeon_cs_ioctl+0x368/0xb90 [radeon]
```

after allocating chunks with __GFP_KERNEL/kvcalloc, this bug is fixed.
Signed-off-by: Chen Li <chenli@uniontech.com>
---
 drivers/gpu/drm/radeon/radeon_cs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index fb736ef9f9aa..059431689c2d 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -93,8 +93,8 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
 	p->dma_reloc_idx = 0;
 	/* FIXME: we assume that each relocs use 4 dwords */
 	p->nrelocs = chunk->length_dw / 4;
-	p->relocs = kvmalloc_array(p->nrelocs, sizeof(struct radeon_bo_list),
-			GFP_KERNEL | __GFP_ZERO);
+	p->relocs = kvcalloc(p->nrelocs, sizeof(struct radeon_bo_list),
+			GFP_KERNEL);
 	if (p->relocs == NULL) {
 		return -ENOMEM;
 	}
@@ -299,7 +299,7 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 	}
 	p->cs_flags = 0;
 	p->nchunks = cs->num_chunks;
-	p->chunks = kvmalloc_array(p->nchunks, sizeof(struct radeon_cs_chunk), GFP_KERNEL);
+	p->chunks = kvcalloc(p->nchunks, sizeof(struct radeon_cs_chunk), GFP_KERNEL);
 	if (p->chunks == NULL) {
 		return -ENOMEM;
 	}
-- 
2.30.1



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