Hi Babu,
On Fri, May 16, 2025 at 12:56 AM Babu Moger <babu.moger@xxxxxxx> wrote:
> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
> index 8d970b99bbbd..ea1782723f81 100644
> --- a/fs/resctrl/rdtgroup.c
> +++ b/fs/resctrl/rdtgroup.c
> @@ -2126,6 +2126,168 @@ static int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file
> return ret;
> }
>
> +/*
> + * mbm_get_mon_event_by_name() - Return the mon_evt entry for the matching
> + * event name.
> + */
> +static struct mon_evt *mbm_get_mon_event_by_name(struct rdt_resource *r,
> + char *name)
> +{
> + struct mon_evt *mevt;
> +
> + list_for_each_entry(mevt, &r->mon.evt_list, list) {
> + if (!strcmp(mevt->name, name))
> + return mevt;
> + }
> +
> + return NULL;
> +}
> +
> +static unsigned int resctrl_get_assing_type(char *assign)
> +{
> + unsigned int mon_state = ASSIGN_NONE;
> + int len = strlen(assign);
[ 395.013183] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 395.013426] #PF: supervisor read access in kernel mode
[ 395.013600] #PF: error_code(0x0000) - not-present page
[ 395.013779] PGD 39322c067 P4D 2a4f49067 PUD 2a4f4a067 PMD 0
[ 395.013973] Oops: Oops: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI
[ 395.014156] CPU: 37 UID: 0 PID: 24147 Comm: bash Not tainted
6.15.0-dbg-DEV #13 NONE
[ 395.014403] Hardware name: Google Astoria-Turin/astoria, BIOS
0.20241223.2-0 01/17/2025
[ 395.014652] RIP: 0010:strlen+0xb/0x20
[ 395.014778] Code: 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90
90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 c7 c0 ff
ff ff ff <80> 7c 07 01 00 48 8d 40 01 75 f5 c3 cc cc cc cc cc 0f 1f 40
00 90
[ 395.015356] RSP: 0018:ffa000002f743d58 EFLAGS: 00010246
[ 395.015522] RAX: ffffffffffffffff RBX: ff11000129a00600 RCX: 0000000000000000
[ 395.015747] RDX: ff110001299f5253 RSI: ffffffff827b9651 RDI: 0000000000000000
[ 395.015968] RBP: 0000000000000000 R08: 000000000000003d R09: 0000000000000000
[ 395.016202] R10: ffffffff827b9652 R11: 0000000000000000 R12: ffffffff8305b7f8
[ 395.016421] R13: ff110001299f5240 R14: 0000000000000014 R15: 0000000000000000
[ 395.016644] FS: 00007f1281ff8b80(0000) GS:ff1100bdc8276000(0000)
knlGS:0000000000000000
[ 395.016893] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 395.017071] CR2: 0000000000000000 CR3: 0000000420bc8002 CR4: 0000000000771ef0
[ 395.017298] PKRU: 55555554
[ 395.017388] Call Trace:
[ 395.017471] <TASK>
[ 395.017545] mbm_L3_assignments_write+0x2d4/0x4e0
[ 395.017700] kernfs_fop_write_iter+0x132/0x1c0
[ 395.017851] vfs_write+0x2bf/0x3c0
[ 395.017963] ksys_write+0x82/0x100
[ 395.018074] do_syscall_64+0xee/0x210
[ 395.018198] ? exc_page_fault+0x81/0xe0
[ 395.018321] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 395.018482] RIP: 0033:0x7f128177f8b3
[ 395.018598] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
cc cc cc cc cc cc cc 48 8b 05 99 91 07 00 83 38 00 75 10 b8 01 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 4d c3 55 48 89 e5 41 57 41 56 53 50 48
89 d3
[ 395.019167] RSP: 002b:00007ffff66e80f8 EFLAGS: 00000246 ORIG_RAX:
0000000000000001
[ 395.019409] RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 00007f128177f8b3
[ 395.019636] RDX: 0000000000000014 RSI: 0000000001eedb60 RDI: 0000000000000001
[ 395.019861] RBP: 00007ffff66e8120 R08: 0000000000000000 R09: 0000000000000000
[ 395.020081] R10: 00007ffff66e81b0 R11: 0000000000000246 R12: 0000000001eedb60
[ 395.020303] R13: 0000000000000001 R14: 00007f12817fa650 R15: 0000000000000014
[ 395.020532] </TASK>
> +
> + if (!len || len > 1)
> + return ASSIGN_INVALID;
> +
> + switch (*assign) {
> + case 'e':
> + mon_state = ASSIGN_EXCLUSIVE;
> + break;
> + case '_':
> + mon_state = ASSIGN_NONE;
> + break;
> + default:
> + mon_state = ASSIGN_INVALID;
> + break;
> + }
> +
> + return mon_state;
> +}
> +
> +static int resctrl_process_assign(struct rdt_resource *r, struct rdtgroup *rdtgrp,
> + char *config, char *tok)
> +{
> + struct rdt_mon_domain *d;
> + char *dom_str, *id_str;
> + unsigned long dom_id = 0;
> + struct mon_evt *mevt;
> + int assign_type;
> + char domain[10];
> + bool found;
> + int ret;
> +
> + mevt = mbm_get_mon_event_by_name(r, config);
> + if (!mevt) {
> + rdt_last_cmd_printf("Invalid assign configuration %s\n", config);
> + return -ENOENT;
> + }
> +
> +next:
> + if (!tok || tok[0] == '\0')
> + return 0;
> +
> + /* Start processing the strings for each domain */
> + dom_str = strim(strsep(&tok, ";"));
> +
> + id_str = strsep(&dom_str, "=");
If there's no '=' then dom_str becomes NULL...
> +
> + /* Check for domain id '*' which means all domains */
> + if (id_str && *id_str == '*') {
> + d = NULL;
> + goto check_state;
> + } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
> + rdt_last_cmd_puts("Missing domain id\n");
> + return -EINVAL;
> + }
> +
> + /* Verify if the dom_id is valid */
> + found = false;
> + list_for_each_entry(d, &r->mon_domains, hdr.list) {
> + if (d->hdr.id == dom_id) {
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found) {
> + rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id);
> + return -EINVAL;
> + }
> +
> +check_state:
> + assign_type = resctrl_get_assing_type(dom_str);
then the resulting type of whatever this is supposed to mean is "panic"
Thanks,
-Peter
