From 83d18e9d9c0150d98dc24e3642ea93f5e245322c Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Thu, 13 Oct 2022 15:55:13 -0700 Subject: drm/msm/a6xx: Fix kvzalloc vs state_kcalloc usage adreno_show_object() is a trap! It will re-allocate the pointer it is passed on first call, when the data is ascii85 encoded, using kvmalloc/ kvfree(). Which means the data *passed* to it must be kvmalloc'd, ie. we cannot use the state_kcalloc() helper. This partially reverts commit ec8f1813bf8d ("drm/msm/a6xx: Replace kcalloc() with kvzalloc()"), but adds the missing kvfree() to fix the memory leak that was present previously. And adds a warning comment. Fixes: ec8f1813bf8d ("drm/msm/a6xx: Replace kcalloc() with kvzalloc()") Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/20 Signed-off-by: Rob Clark Reviewed-by: Chia-I Wu Reviewed-by: Akhil P Oommen Patchwork: https://patchwork.freedesktop.org/patch/507014/ Link: https://lore.kernel.org/r/20221013225520.371226-2-robdclark@gmail.com --- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/msm/adreno/adreno_gpu.c') diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index 382fb7f9e497..5a0e8491cd3a 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -729,7 +729,12 @@ static char *adreno_gpu_ascii85_encode(u32 *src, size_t len) return buf; } -/* len is expected to be in bytes */ +/* len is expected to be in bytes + * + * WARNING: *ptr should be allocated with kvmalloc or friends. It can be free'd + * with kvfree() and replaced with a newly kvmalloc'd buffer on the first call + * when the unencoded raw data is encoded + */ void adreno_show_object(struct drm_printer *p, void **ptr, int len, bool *encoded) { -- cgit v1.2.3