From d73610211eec8aa027850982b1a48980aa1bc96e Mon Sep 17 00:00:00 2001 From: Qu Huang Date: Sun, 21 Mar 2021 16:28:18 +0800 Subject: [PATCH] drm/amdkfd: Fix cat debugfs hang_hws file causes system crash bug Here is the system crash log: [ 1272.884438] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1272.884444] IP: [< (null)>] (null) [ 1272.884447] PGD 825b09067 PUD 8267c8067 PMD 0 [ 1272.884452] Oops: 0010 [#1] SMP [ 1272.884509] CPU: 13 PID: 3485 Comm: cat Kdump: loaded Tainted: G [ 1272.884515] task: ffff9a38dbd4d140 ti: ffff9a37cd3b8000 task.ti: ffff9a37cd3b8000 [ 1272.884517] RIP: 0010:[<0000000000000000>] [< (null)>] (null) [ 1272.884520] RSP: 0018:ffff9a37cd3bbe68 EFLAGS: 00010203 [ 1272.884522] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000014d5f [ 1272.884524] RDX: fffffffffffffff4 RSI: 0000000000000001 RDI: ffff9a38aca4d200 [ 1272.884526] RBP: ffff9a37cd3bbed0 R08: ffff9a38dcd5f1a0 R09: ffff9a31ffc07300 [ 1272.884527] R10: ffff9a31ffc07300 R11: ffffffffaddd5e9d R12: ffff9a38b4e0fb00 [ 1272.884529] R13: 0000000000000001 R14: ffff9a37cd3bbf18 R15: ffff9a38aca4d200 [ 1272.884532] FS: 00007feccaa67740(0000) GS:ffff9a38dcd40000(0000) knlGS:0000000000000000 [ 1272.884534] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1272.884536] CR2: 0000000000000000 CR3: 00000008267c0000 CR4: 00000000003407e0 [ 1272.884537] Call Trace: [ 1272.884544] [] ? seq_read+0x130/0x440 [ 1272.884548] [] vfs_read+0x9f/0x170 [ 1272.884552] [] SyS_read+0x7f/0xf0 [ 1272.884557] [] system_call_fastpath+0x22/0x27 [ 1272.884558] Code: Bad RIP value. [ 1272.884562] RIP [< (null)>] (null) [ 1272.884564] RSP [ 1272.884566] CR2: 0000000000000000 Signed-off-by: Qu Huang Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c index 511712c2e382..673d5e34f213 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c @@ -33,6 +33,11 @@ static int kfd_debugfs_open(struct inode *inode, struct file *file) return single_open(file, show, NULL); } +static int kfd_debugfs_hang_hws_read(struct seq_file *m, void *data) +{ + seq_printf(m, "echo gpu_id > hang_hws\n"); + return 0; +} static ssize_t kfd_debugfs_hang_hws_write(struct file *file, const char __user *user_buf, size_t size, loff_t *ppos) @@ -94,7 +99,7 @@ void kfd_debugfs_init(void) debugfs_create_file("rls", S_IFREG | 0444, debugfs_root, kfd_debugfs_rls_by_device, &kfd_debugfs_fops); debugfs_create_file("hang_hws", S_IFREG | 0200, debugfs_root, - NULL, &kfd_debugfs_hang_hws_fops); + kfd_debugfs_hang_hws_read, &kfd_debugfs_hang_hws_fops); } void kfd_debugfs_fini(void) -- 2.11.0