From: Felix Kuehling Felix.Kuehling@amd.com

[ Upstream commit 726be40607264b180a2b336c81e1dcff941de618 ]

Add null-pointer check after the last svm_range_new call. This was originally reported by Zhou Qingyang zhou1615@umn.edu based on a static analyzer.

To avoid duplicating the unwinding code from svm_range_handle_overlap, I merged the two functions into one.

Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com Cc: Zhou Qingyang zhou1615@umn.edu Reviewed-by: Philip Yang Philip.Yang@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 138 ++++++++++----------------- 1 file changed, 49 insertions(+), 89 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 5a674235ae41a..830809b694dd9 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -936,7 +936,7 @@ svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last, }

static int -svm_range_split_tail(struct svm_range *prange, struct svm_range *new, +svm_range_split_tail(struct svm_range *prange, uint64_t new_last, struct list_head *insert_list) { struct svm_range *tail; @@ -948,7 +948,7 @@ svm_range_split_tail(struct svm_range *prange, struct svm_range *new, }

static int -svm_range_split_head(struct svm_range *prange, struct svm_range *new, +svm_range_split_head(struct svm_range *prange, uint64_t new_start, struct list_head *insert_list) { struct svm_range *head; @@ -1755,49 +1755,54 @@ static struct svm_range *svm_range_clone(struct svm_range *old) }

/** - * svm_range_handle_overlap - split overlap ranges - * @svms: svm range list header - * @new: range added with this attributes - * @start: range added start address, in pages - * @last: range last address, in pages - * @update_list: output, the ranges attributes are updated. For set_attr, this - * will do validation and map to GPUs. For unmap, this will be - * removed and unmap from GPUs - * @insert_list: output, the ranges will be inserted into svms, attributes are - * not changes. For set_attr, this will add into svms. - * @remove_list:output, the ranges will be removed from svms - * @left: the remaining range after overlap, For set_attr, this will be added - * as new range. + * svm_range_add - add svm range and handle overlap + * @p: the range add to this process svms + * @start: page size aligned + * @size: page size aligned + * @nattr: number of attributes + * @attrs: array of attributes + * @update_list: output, the ranges need validate and update GPU mapping + * @insert_list: output, the ranges need insert to svms + * @remove_list: output, the ranges are replaced and need remove from svms * - * Total have 5 overlap cases. + * Check if the virtual address range has overlap with any existing ranges, + * split partly overlapping ranges and add new ranges in the gaps. All changes + * should be applied to the range_list and interval tree transactionally. If + * any range split or allocation fails, the entire update fails. Therefore any + * existing overlapping svm_ranges are cloned and the original svm_ranges left + * unchanged. * - * This function handles overlap of an address interval with existing - * struct svm_ranges for applying new attributes. This may require - * splitting existing struct svm_ranges. All changes should be applied to - * the range_list and interval tree transactionally. If any split operation - * fails, the entire update fails. Therefore the existing overlapping - * svm_ranges are cloned and the original svm_ranges left unchanged. If the - * transaction succeeds, the modified clones are added and the originals - * freed. Otherwise the clones are removed and the old svm_ranges remain. + * If the transaction succeeds, the caller can update and insert clones and + * new ranges, then free the originals. * - * Context: The caller must hold svms->lock + * Otherwise the caller can free the clones and new ranges, while the old + * svm_ranges remain unchanged. + * + * Context: Process context, caller must hold svms->lock + * + * Return: + * 0 - OK, otherwise error code */ static int -svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new, - unsigned long start, unsigned long last, - struct list_head *update_list, - struct list_head *insert_list, - struct list_head *remove_list, - unsigned long *left) +svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size, + uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs, + struct list_head *update_list, struct list_head *insert_list, + struct list_head *remove_list) { + unsigned long last = start + size - 1UL; + struct svm_range_list *svms = &p->svms; struct interval_tree_node *node; + struct svm_range new = {0}; struct svm_range *prange; struct svm_range *tmp; int r = 0;

+ pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last); + INIT_LIST_HEAD(update_list); INIT_LIST_HEAD(insert_list); INIT_LIST_HEAD(remove_list); + svm_range_apply_attrs(p, &new, nattr, attrs);

node = interval_tree_iter_first(&svms->objects, start, last); while (node) { @@ -1825,14 +1830,14 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new,

if (node->start < start) { pr_debug("change old range start\n"); - r = svm_range_split_head(prange, new, start, + r = svm_range_split_head(prange, start, insert_list); if (r) goto out; } if (node->last > last) { pr_debug("change old range last\n"); - r = svm_range_split_tail(prange, new, last, + r = svm_range_split_tail(prange, last, insert_list); if (r) goto out; @@ -1844,7 +1849,7 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new, prange = old; }

- if (!svm_range_is_same_attrs(prange, new)) + if (!svm_range_is_same_attrs(prange, &new)) list_add(&prange->update_list, update_list);

/* insert a new node if needed */ @@ -1864,8 +1869,16 @@ svm_range_handle_overlap(struct svm_range_list *svms, struct svm_range *new, start = next_start; }

- if (left && start <= last) - *left = last - start + 1; + /* add a final range at the end if needed */ + if (start <= last) { + prange = svm_range_new(svms, start, last); + if (!prange) { + r = -ENOMEM; + goto out; + } + list_add(&prange->insert_list, insert_list); + list_add(&prange->update_list, update_list); + }

out: if (r) @@ -2693,59 +2706,6 @@ svm_range_is_valid(struct mm_struct *mm, uint64_t start, uint64_t size) return true; }

-/** - * svm_range_add - add svm range and handle overlap - * @p: the range add to this process svms - * @start: page size aligned - * @size: page size aligned - * @nattr: number of attributes - * @attrs: array of attributes - * @update_list: output, the ranges need validate and update GPU mapping - * @insert_list: output, the ranges need insert to svms - * @remove_list: output, the ranges are replaced and need remove from svms - * - * Check if the virtual address range has overlap with the registered ranges, - * split the overlapped range, copy and adjust pages address and vram nodes in - * old and new ranges. - * - * Context: Process context, caller must hold svms->lock - * - * Return: - * 0 - OK, otherwise error code - */ -static int -svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size, - uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs, - struct list_head *update_list, struct list_head *insert_list, - struct list_head *remove_list) -{ - uint64_t last = start + size - 1UL; - struct svm_range_list *svms; - struct svm_range new = {0}; - struct svm_range *prange; - unsigned long left = 0; - int r = 0; - - pr_debug("svms 0x%p [0x%llx 0x%llx]\n", &p->svms, start, last); - - svm_range_apply_attrs(p, &new, nattr, attrs); - - svms = &p->svms; - - r = svm_range_handle_overlap(svms, &new, start, last, update_list, - insert_list, remove_list, &left); - if (r) - return r; - - if (left) { - prange = svm_range_new(svms, last - left + 1, last); - list_add(&prange->insert_list, insert_list); - list_add(&prange->update_list, update_list); - } - - return 0; -} - /** * svm_range_best_prefetch_location - decide the best prefetch location * @prange: svm range structure