[RFC PATCH 21/39] sysctl: refresh device-dependent bounds per call

[wen . yang]

From: Wen Yang <wen.yang@xxxxxxxxx>

Refresh device-dependent limits before validating sysctl writes.

Suggested-by: Joel Granados <joel.granados@xxxxxxxxxx>
Signed-off-by: Wen Yang <wen.yang@xxxxxxxxx>
---
 drivers/base/power/main.c        | 21 +++++++++++++++------
 drivers/gpu/drm/i915/i915_perf.c | 19 ++++++++++++++-----
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 88a31e09e4f3..8346875a4fa2 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -543,7 +543,6 @@ MODULE_PARM_DESC(dpm_watchdog_enabled, "Enable DPM watchdog");
 static unsigned int __read_mostly dpm_watchdog_timeout = CONFIG_DPM_WATCHDOG_TIMEOUT;
 static unsigned int __read_mostly dpm_watchdog_warning_timeout =
 						CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT;
-static const unsigned int dpm_watchdog_timeout_max = CONFIG_DPM_WATCHDOG_TIMEOUT;
 
 static int proc_dodpm_watchdog_timeout_secs(const struct ctl_table *table,
 					    int write, void *buffer,
@@ -565,23 +564,33 @@ static int proc_dodpm_watchdog_timeout_secs(const struct ctl_table *table,
 	return 0;
 }
 
+static int proc_dodpm_watchdog_warning_timeout_secs(const struct ctl_table *table,
+						    int write, void *buffer, size_t *lenp,
+						    loff_t *ppos)
+{
+	struct ctl_table tmp = *table;
+
+	tmp.max = READ_ONCE(dpm_watchdog_timeout);
+	return proc_douintvec_minmax(&tmp, write, buffer, lenp, ppos);
+}
+
 static const struct ctl_table dpm_watchdog_sysctls[] = {
 	{
 		.procname	= "dpm_watchdog_timeout_secs",
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= proc_dodpm_watchdog_timeout_secs,
-		.extra1		= SYSCTL_ONE,
-		.extra2		= (void *)&dpm_watchdog_timeout_max,
+		.min		= 1,
+		.max		= CONFIG_DPM_WATCHDOG_TIMEOUT,
 	},
 	{
 		.procname	= "dpm_watchdog_warning_timeout_secs",
 		.data		= &dpm_watchdog_warning_timeout,
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
-		.proc_handler	= proc_douintvec_minmax,
-		.extra1		= SYSCTL_ONE,
-		.extra2		= (void *)&dpm_watchdog_timeout,
+		.proc_handler	= proc_dodpm_watchdog_warning_timeout_secs,
+		.min		= 1,
+		.max		= UINT_MAX,
 	},
 };
 
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 19b82427aa41..2e758f2008db 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -4795,6 +4795,15 @@ int i915_perf_remove_config_ioctl(struct drm_device *dev, void *data,
 	return ret;
 }
 
+static int oa_max_sample_rate_handler(const struct ctl_table *table, int write,
+				      void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table tmp = *table;
+
+	tmp.max = (unsigned long)READ_ONCE(oa_sample_rate_hard_limit);
+	return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+}
+
 static const struct ctl_table oa_table[] = {
 	{
 	 .procname = "perf_stream_paranoid",
@@ -4802,17 +4811,17 @@ static const struct ctl_table oa_table[] = {
 	 .maxlen = sizeof(i915_perf_stream_paranoid),
 	 .mode = 0644,
 	 .proc_handler = proc_dointvec_minmax,
-	 .extra1 = SYSCTL_ZERO,
-	 .extra2 = SYSCTL_ONE,
+	 .min = 0,
+	 .max = 1,
 	 },
 	{
 	 .procname = "oa_max_sample_rate",
 	 .data = &i915_oa_max_sample_rate,
 	 .maxlen = sizeof(i915_oa_max_sample_rate),
 	 .mode = 0644,
-	 .proc_handler = proc_dointvec_minmax,
-	 .extra1 = SYSCTL_ZERO,
-	 .extra2 = &oa_sample_rate_hard_limit,
+	 .proc_handler = oa_max_sample_rate_handler,
+	 .min = 0,
+	 .max = INT_MAX,
 	 },
 };
 
-- 
2.25.1