drm/amdkfd: Fix possible infinite loop

When the loop predicating timeout parameter passed happens to
not be a multiple of 20 the unsigned integer will overflow and
the loop will become unbounded.

Signed-off-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
index 362bedc..1a0a5f7 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
@@ -103,11 +103,11 @@ static bool kgd_hqd_is_occupied(struct kgd_dev *kgd, uint64_t queue_address,
                                uint32_t pipe_id, uint32_t queue_id);
 
 static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
-                               unsigned int timeout, uint32_t pipe_id,
+                               unsigned int utimeout, uint32_t pipe_id,
                                uint32_t queue_id);
 static bool kgd_hqd_sdma_is_occupied(struct kgd_dev *kgd, void *mqd);
 static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
-                               unsigned int timeout);
+                               unsigned int utimeout);
 static int kgd_address_watch_disable(struct kgd_dev *kgd);
 static int kgd_address_watch_execute(struct kgd_dev *kgd,
                                        unsigned int watch_point_id,
@@ -437,11 +437,12 @@ static bool kgd_hqd_sdma_is_occupied(struct kgd_dev *kgd, void *mqd)
 }
 
 static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
-                               unsigned int timeout, uint32_t pipe_id,
+                               unsigned int utimeout, uint32_t pipe_id,
                                uint32_t queue_id)
 {
        struct amdgpu_device *adev = get_amdgpu_device(kgd);
        uint32_t temp;
+       int timeout = utimeout;
 
        acquire_queue(kgd, pipe_id, queue_id);
        WREG32(mmCP_HQD_PQ_DOORBELL_CONTROL, 0);
@@ -452,9 +453,8 @@ static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
                temp = RREG32(mmCP_HQD_ACTIVE);
                if (temp & CP_HQD_ACTIVE__ACTIVE_MASK)
                        break;
-               if (timeout == 0) {
-                       pr_err("kfd: cp queue preemption time out (%dms)\n",
-                               temp);
+               if (timeout <= 0) {
+                       pr_err("kfd: cp queue preemption time out.\n");
                        release_queue(kgd);
                        return -ETIME;
                }
@@ -467,12 +467,13 @@ static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
 }
 
 static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
-                               unsigned int timeout)
+                               unsigned int utimeout)
 {
        struct amdgpu_device *adev = get_amdgpu_device(kgd);
        struct cik_sdma_rlc_registers *m;
        uint32_t sdma_base_addr;
        uint32_t temp;
+       int timeout = utimeout;
 
        m = get_sdma_mqd(mqd);
        sdma_base_addr = get_sdma_base_addr(m);
@@ -485,7 +486,7 @@ static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
                temp = RREG32(sdma_base_addr + mmSDMA0_RLC0_CONTEXT_STATUS);
                if (temp & SDMA0_STATUS_REG__RB_CMD_IDLE__SHIFT)
                        break;
-               if (timeout == 0)
+               if (timeout <= 0)
                        return -ETIME;
                msleep(20);
                timeout -= 20;

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
index 04b744d..6697612 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
@@ -62,10 +62,10 @@ static bool kgd_hqd_is_occupied(struct kgd_dev *kgd, uint64_t queue_address,
                uint32_t pipe_id, uint32_t queue_id);
 static bool kgd_hqd_sdma_is_occupied(struct kgd_dev *kgd, void *mqd);
 static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
-                               unsigned int timeout, uint32_t pipe_id,
+                               unsigned int utimeout, uint32_t pipe_id,
                                uint32_t queue_id);
 static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
-                               unsigned int timeout);
+                               unsigned int utimeout);
 static void write_vmid_invalidate_request(struct kgd_dev *kgd, uint8_t vmid);
 static int kgd_address_watch_disable(struct kgd_dev *kgd);
 static int kgd_address_watch_execute(struct kgd_dev *kgd,
@@ -349,11 +349,12 @@ static bool kgd_hqd_sdma_is_occupied(struct kgd_dev *kgd, void *mqd)
 }
 
 static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
-                               unsigned int timeout, uint32_t pipe_id,
+                               unsigned int utimeout, uint32_t pipe_id,
                                uint32_t queue_id)
 {
        struct amdgpu_device *adev = get_amdgpu_device(kgd);
        uint32_t temp;
+       int timeout = utimeout;
 
        acquire_queue(kgd, pipe_id, queue_id);
 
@@ -363,9 +364,8 @@ static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
                temp = RREG32(mmCP_HQD_ACTIVE);
                if (temp & CP_HQD_ACTIVE__ACTIVE_MASK)
                        break;
-               if (timeout == 0) {
-                       pr_err("kfd: cp queue preemption time out (%dms)\n",
-                               temp);
+               if (timeout <= 0) {
+                       pr_err("kfd: cp queue preemption time out.\n");
                        release_queue(kgd);
                        return -ETIME;
                }
@@ -378,12 +378,13 @@ static int kgd_hqd_destroy(struct kgd_dev *kgd, uint32_t reset_type,
 }
 
 static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
-                               unsigned int timeout)
+                               unsigned int utimeout)
 {
        struct amdgpu_device *adev = get_amdgpu_device(kgd);
        struct cik_sdma_rlc_registers *m;
        uint32_t sdma_base_addr;
        uint32_t temp;
+       int timeout = utimeout;
 
        m = get_sdma_mqd(mqd);
        sdma_base_addr = get_sdma_base_addr(m);
@@ -396,7 +397,7 @@ static int kgd_hqd_sdma_destroy(struct kgd_dev *kgd, void *mqd,
                temp = RREG32(sdma_base_addr + mmSDMA0_RLC0_CONTEXT_STATUS);
                if (temp & SDMA0_STATUS_REG__RB_CMD_IDLE__SHIFT)
                        break;
-               if (timeout == 0)
+               if (timeout <= 0)
                        return -ETIME;
                msleep(20);
                timeout -= 20;