From 2677a7680e773195a4fdabd163d756cac1b9abd7 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 28 Jul 2016 15:21:26 -0400 Subject: [PATCH] IB/hfi1: Fix memory leak during unexpected shutdown During an unexpected shutdown, references to tid_rb_node were NULL'ed out without properly being released. Fix this by calling clear_tid_node in the mmu notifier remove callback rather than after these callbacks are called. Reviewed-by: Dean Luick Signed-off-by: Ira Weiny Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/user_exp_rcv.c | 44 ++++++++++++++++------- 1 file changed, 31 insertions(+), 13 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c index 8717e11fe3f5..64d26525435a 100644 --- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c +++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c @@ -87,13 +87,15 @@ static u32 find_phys_blocks(struct page **, unsigned, struct tid_pageset *); static int set_rcvarray_entry(struct file *, unsigned long, u32, struct tid_group *, struct page **, unsigned); static int tid_rb_insert(void *, struct mmu_rb_node *); +static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata, + struct tid_rb_node *tnode); static void tid_rb_remove(void *, struct mmu_rb_node *); static int tid_rb_invalidate(void *, struct mmu_rb_node *); static int program_rcvarray(struct file *, unsigned long, struct tid_group *, struct tid_pageset *, unsigned, u16, struct page **, u32 *, unsigned *, unsigned *); static int unprogram_rcvarray(struct file *, u32, struct tid_group **); -static void clear_tid_node(struct hfi1_filedata *, struct tid_rb_node *); +static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node); static struct mmu_rb_ops tid_rb_ops = { .insert = tid_rb_insert, @@ -899,14 +901,15 @@ static int unprogram_rcvarray(struct file *fp, u32 tidinfo, node = fd->entry_to_rb[rcventry]; if (!node || node->rcventry != (uctxt->expected_base + rcventry)) return -EBADF; + + if (grp) + *grp = node->grp; + if (!fd->handler) - tid_rb_remove(fd, &node->mmu); + cacheless_tid_rb_remove(fd, node); else hfi1_mmu_rb_remove(fd->handler, &node->mmu); - if (grp) - *grp = node->grp; - clear_tid_node(fd, node); return 0; } @@ -943,6 +946,10 @@ static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node) kfree(node); } +/* + * As a simple helper for hfi1_user_exp_rcv_free, this function deals with + * clearing nodes in the non-cached case. + */ static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt, struct exp_tid_set *set, struct hfi1_filedata *fd) @@ -962,17 +969,20 @@ static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt, uctxt->expected_base]; if (!node || node->rcventry != rcventry) continue; - if (!fd->handler) - tid_rb_remove(fd, &node->mmu); - else - hfi1_mmu_rb_remove(fd->handler, - &node->mmu); - clear_tid_node(fd, node); + + cacheless_tid_rb_remove(fd, node); } } } } +/* + * Always return 0 from this function. A non-zero return indicates that the + * remove operation will be called and that memory should be unpinned. + * However, the driver cannot unpin out from under PSM. Instead, retain the + * memory (by returning 0) and inform PSM that the memory is going away. PSM + * will call back later when it has removed the memory from its list. + */ static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode) { struct hfi1_filedata *fdata = arg; @@ -1027,12 +1037,20 @@ static int tid_rb_insert(void *arg, struct mmu_rb_node *node) return 0; } +static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata, + struct tid_rb_node *tnode) +{ + u32 base = fdata->uctxt->expected_base; + + fdata->entry_to_rb[tnode->rcventry - base] = NULL; + clear_tid_node(fdata, tnode); +} + static void tid_rb_remove(void *arg, struct mmu_rb_node *node) { struct hfi1_filedata *fdata = arg; struct tid_rb_node *tnode = container_of(node, struct tid_rb_node, mmu); - u32 base = fdata->uctxt->expected_base; - fdata->entry_to_rb[tnode->rcventry - base] = NULL; + cacheless_tid_rb_remove(fdata, tnode); } -- 2.20.1