File 0037-LU-13783-libcfs-don-t-depend-on-sysctl-support-for-d.patch of Package lustre_2_12
From d707b390aec5e95a1aec9910fb3c8248c231cbfb Mon Sep 17 00:00:00 2001
From: Mr NeilBrown <neilb@suse.de>
Date: Thu, 12 Nov 2020 11:16:28 +1100
Subject: [PATCH] LU-13783 libcfs: don't depend on sysctl support for debugfs
Since Linux v5.8-rc1~55^2~6 sysctl support routines like
proc_dointvec() expect a pointer to kernel-space, not userspace.
So stop using these function for debugfs files, and instead
provide bespoke functions.
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I340a748bbfbd066054a73299ce32698aa39a0e2d
Reviewed-on: https://review.whamcloud.com/40832
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---
libcfs/include/libcfs/libcfs.h | 2
libcfs/libcfs/module.c | 113 ++++++++++++++++++++++++++++++++++++++---
2 files changed, 108 insertions(+), 7 deletions(-)
--- a/libcfs/include/libcfs/libcfs.h
+++ b/libcfs/include/libcfs/libcfs.h
@@ -160,6 +160,8 @@ int lprocfs_call_handler(void *data, int
void __user *buffer, size_t *lenp,
int (*handler)(void *data, int write, loff_t pos,
void __user *buffer, int len));
+int debugfs_doint(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos);
/* atomic-context safe vfree */
#ifdef HAVE_LIBCFS_VFREE_ATOMIC
--- a/libcfs/libcfs/module.c
+++ b/libcfs/libcfs/module.c
@@ -244,12 +244,111 @@ static int proc_fail_loc(struct ctl_tabl
int rc;
long old_fail_loc = cfs_fail_loc;
- rc = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+ if (!*lenp || *ppos) {
+ *lenp = 0;
+ return 0;
+ }
+
+ if (write) {
+ char *kbuf = memdup_user_nul(buffer, *lenp);
+
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ rc = kstrtoul(kbuf, 0, &cfs_fail_loc);
+ kfree(kbuf);
+ *ppos += *lenp;
+ } else {
+ char kbuf[64/3+3];
+
+ rc = scnprintf(kbuf, sizeof(kbuf), "%lu\n", cfs_fail_loc);
+ if (copy_to_user(buffer, kbuf, rc))
+ rc = -EFAULT;
+ else {
+ *lenp = rc;
+ *ppos += rc;
+ }
+ }
+
if (old_fail_loc != cfs_fail_loc)
wake_up(&cfs_race_waitq);
return rc;
}
+int debugfs_doint(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ int rc;
+
+ if (!*lenp || *ppos) {
+ *lenp = 0;
+ return 0;
+ }
+
+ if (write) {
+ char *kbuf = memdup_user_nul(buffer, *lenp);
+ int val;
+
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ rc = kstrtoint(kbuf, 0, &val);
+ kfree(kbuf);
+ if (!rc) {
+ if (table->extra1 && val < *(int *)table->extra1)
+ val = *(int *)table->extra1;
+ if (table->extra2 && val > *(int *)table->extra2)
+ val = *(int *)table->extra2;
+ *(int *)table->data = val;
+ }
+ *ppos += *lenp;
+ } else {
+ char kbuf[64/3+3];
+
+ rc = scnprintf(kbuf, sizeof(kbuf), "%u\n", *(int *)table->data);
+ if (copy_to_user(buffer, kbuf, rc))
+ rc = -EFAULT;
+ else {
+ *lenp = rc;
+ *ppos += rc;
+ }
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(debugfs_doint);
+
+static int debugfs_dostring(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ int len = *lenp;
+ char *kbuf = table->data;
+
+ if (!len || *ppos) {
+ *lenp = 0;
+ return 0;
+ }
+ if (len > table->maxlen)
+ len = table->maxlen;
+ if (write) {
+ if (copy_from_user(kbuf, buffer, len))
+ return -EFAULT;
+ memset(kbuf+len, 0, table->maxlen - len);
+ *ppos = *lenp;
+ } else {
+ len = strnlen(kbuf, len);
+ if (copy_to_user(buffer, kbuf, len))
+ return -EFAULT;
+ if (len < *lenp) {
+ if (copy_to_user(buffer+len, "\n", 1))
+ return -EFAULT;
+ len += 1;
+ }
+ *ppos += len;
+ *lenp -= len;
+ }
+ return len;
+}
+
static int __proc_cpt_table(void *data, int write,
loff_t pos, void __user *buffer, int nob)
{
@@ -391,7 +490,7 @@ static struct ctl_table lnet_table[] = {
.data = lnet_debug_log_upcall,
.maxlen = sizeof(lnet_debug_log_upcall),
.mode = 0644,
- .proc_handler = &proc_dostring,
+ .proc_handler = &debugfs_dostring,
},
{
INIT_CTL_NAME
@@ -399,7 +498,7 @@ static struct ctl_table lnet_table[] = {
.data = (int *)&libcfs_kmemory.counter,
.maxlen = sizeof(int),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &debugfs_doint,
},
{
INIT_CTL_NAME
@@ -407,7 +506,7 @@ static struct ctl_table lnet_table[] = {
.data = &libcfs_catastrophe,
.maxlen = sizeof(int),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &debugfs_doint,
},
{
INIT_CTL_NAME
@@ -429,7 +528,7 @@ static struct ctl_table lnet_table[] = {
.data = &libcfs_watchdog_ratelimit,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_minmax,
+ .proc_handler = &debugfs_doint,
.extra1 = &min_watchdog_ratelimit,
.extra2 = &max_watchdog_ratelimit,
},
@@ -455,7 +554,7 @@ static struct ctl_table lnet_table[] = {
.data = &cfs_fail_val,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec
+ .proc_handler = &debugfs_doint
},
{
INIT_CTL_NAME
@@ -463,7 +562,7 @@ static struct ctl_table lnet_table[] = {
.data = &cfs_fail_err,
.maxlen = sizeof(cfs_fail_err),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &debugfs_doint,
},
{
}
