Rework NMI "action" modparam handling:
1. Replace the uv_nmi_action string with an enum; and
2. Use sysfs_match_string() for string parsing in param_set_action()
Suggested-by: Steve Wahl <[email protected]>
Reviewed-by: Justin Stitt <[email protected]>
Reviewed-by: Steve Wahl <[email protected]>
Tested-by: Steve Wahl <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
---
Changes in v3:
- Add 'include <string.h>'
- Add nmi_act_max and use it for string array sizes
- Stop printing val when it is invalid to avoid issues with
printing unvalidated user input which could e.g. contain a '\n'
- Add Reviewed- / Tested-by tags
Changes in v2:
- Also change uv_nmi_action to an enum to replace a bunch of
strcmp() calls
---
arch/x86/platform/uv/uv_nmi.c | 104 +++++++++++++++++++---------------
1 file changed, 57 insertions(+), 47 deletions(-)
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index 45d0c17ce77c..e03207de2880 100644
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -17,6 +17,7 @@
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/slab.h>
+#include <linux/string.h>
#include <linux/clocksource.h>
#include <asm/apic.h>
@@ -178,49 +179,56 @@ module_param_named(debug, uv_nmi_debug, int, 0644);
} while (0)
/* Valid NMI Actions */
-#define ACTION_LEN 16
-static struct nmi_action {
- char *action;
- char *desc;
-} valid_acts[] = {
- { "kdump", "do kernel crash dump" },
- { "dump", "dump process stack for each cpu" },
- { "ips", "dump Inst Ptr info for each cpu" },
- { "kdb", "enter KDB (needs kgdboc= assignment)" },
- { "kgdb", "enter KGDB (needs gdb target remote)" },
- { "health", "check if CPUs respond to NMI" },
+enum action_t {
+ nmi_act_kdump,
+ nmi_act_dump,
+ nmi_act_ips,
+ nmi_act_kdb,
+ nmi_act_kgdb,
+ nmi_act_health,
+ nmi_act_max
};
-typedef char action_t[ACTION_LEN];
-static action_t uv_nmi_action = { "dump" };
+
+static const char * const actions[nmi_act_max] = {
+ [nmi_act_kdump] = "kdump",
+ [nmi_act_dump] = "dump",
+ [nmi_act_ips] = "ips",
+ [nmi_act_kdb] = "kdb",
+ [nmi_act_kgdb] = "kgdb",
+ [nmi_act_health] = "health",
+};
+
+static const char * const actions_desc[nmi_act_max] = {
+ [nmi_act_kdump] = "do kernel crash dump",
+ [nmi_act_dump] = "dump process stack for each cpu",
+ [nmi_act_ips] = "dump Inst Ptr info for each cpu",
+ [nmi_act_kdb] = "enter KDB (needs kgdboc= assignment)",
+ [nmi_act_kgdb] = "enter KGDB (needs gdb target remote)",
+ [nmi_act_health] = "check if CPUs respond to NMI",
+};
+
+static enum action_t uv_nmi_action = nmi_act_dump;
static int param_get_action(char *buffer, const struct kernel_param *kp)
{
- return sprintf(buffer, "%s\n", uv_nmi_action);
+ return sprintf(buffer, "%s\n", actions[uv_nmi_action]);
}
static int param_set_action(const char *val, const struct kernel_param *kp)
{
- int i;
- int n = ARRAY_SIZE(valid_acts);
- char arg[ACTION_LEN];
+ int i, n = ARRAY_SIZE(actions);
- /* (remove possible '\n') */
- strscpy(arg, val, strnchrnul(val, sizeof(arg)-1, '\n') - val + 1);
-
- for (i = 0; i < n; i++)
- if (!strcmp(arg, valid_acts[i].action))
- break;
-
- if (i < n) {
- strscpy(uv_nmi_action, arg, sizeof(uv_nmi_action));
- pr_info("UV: New NMI action:%s\n", uv_nmi_action);
+ i = sysfs_match_string(actions, val);
+ if (i >= 0) {
+ uv_nmi_action = i;
+ pr_info("UV: New NMI action:%s\n", actions[i]);
return 0;
}
- pr_err("UV: Invalid NMI action:%s, valid actions are:\n", arg);
+ pr_err("UV: Invalid NMI action. Valid actions are:\n");
for (i = 0; i < n; i++)
- pr_err("UV: %-8s - %s\n",
- valid_acts[i].action, valid_acts[i].desc);
+ pr_err("UV: %-8s - %s\n", actions[i], actions_desc[i]);
+
return -EINVAL;
}
@@ -228,15 +236,10 @@ static const struct kernel_param_ops param_ops_action = {
.get = param_get_action,
.set = param_set_action,
};
-#define param_check_action(name, p) __param_check(name, p, action_t)
+#define param_check_action(name, p) __param_check(name, p, enum action_t)
module_param_named(action, uv_nmi_action, action, 0644);
-static inline bool uv_nmi_action_is(const char *action)
-{
- return (strncmp(uv_nmi_action, action, strlen(action)) == 0);
-}
-
/* Setup which NMI support is present in system */
static void uv_nmi_setup_mmrs(void)
{
@@ -727,10 +730,10 @@ static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs)
if (cpu == 0)
uv_nmi_dump_cpu_ip_hdr();
- if (current->pid != 0 || !uv_nmi_action_is("ips"))
+ if (current->pid != 0 || uv_nmi_action != nmi_act_ips)
uv_nmi_dump_cpu_ip(cpu, regs);
- if (uv_nmi_action_is("dump")) {
+ if (uv_nmi_action == nmi_act_dump) {
pr_info("UV:%sNMI process trace for CPU %d\n", dots, cpu);
show_regs(regs);
}
@@ -798,7 +801,7 @@ static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master)
int saved_console_loglevel = console_loglevel;
pr_alert("UV: tracing %s for %d CPUs from CPU %d\n",
- uv_nmi_action_is("ips") ? "IPs" : "processes",
+ uv_nmi_action == nmi_act_ips ? "IPs" : "processes",
atomic_read(&uv_nmi_cpus_in_nmi), cpu);
console_loglevel = uv_nmi_loglevel;
@@ -874,7 +877,7 @@ static inline int uv_nmi_kdb_reason(void)
static inline int uv_nmi_kdb_reason(void)
{
/* Ensure user is expecting to attach gdb remote */
- if (uv_nmi_action_is("kgdb"))
+ if (uv_nmi_action == nmi_act_kgdb)
return 0;
pr_err("UV: NMI error: KDB is not enabled in this kernel\n");
@@ -950,28 +953,35 @@ static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
master = (atomic_read(&uv_nmi_cpu) == cpu);
/* If NMI action is "kdump", then attempt to do it */
- if (uv_nmi_action_is("kdump")) {
+ if (uv_nmi_action == nmi_act_kdump) {
uv_nmi_kdump(cpu, master, regs);
/* Unexpected return, revert action to "dump" */
if (master)
- strscpy(uv_nmi_action, "dump", sizeof(uv_nmi_action));
+ uv_nmi_action = nmi_act_dump;
}
/* Pause as all CPU's enter the NMI handler */
uv_nmi_wait(master);
/* Process actions other than "kdump": */
- if (uv_nmi_action_is("health")) {
+ switch (uv_nmi_action) {
+ case nmi_act_health:
uv_nmi_action_health(cpu, regs, master);
- } else if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) {
+ break;
+ case nmi_act_ips:
+ case nmi_act_dump:
uv_nmi_dump_state(cpu, regs, master);
- } else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb")) {
+ break;
+ case nmi_act_kdb:
+ case nmi_act_kgdb:
uv_call_kgdb_kdb(cpu, regs, master);
- } else {
+ break;
+ default:
if (master)
- pr_alert("UV: unknown NMI action: %s\n", uv_nmi_action);
+ pr_alert("UV: unknown NMI action: %d\n", uv_nmi_action);
uv_nmi_sync_exit(master);
+ break;
}
/* Clear per_cpu "in_nmi" flag */
--
2.41.0
The following commit has been merged into the x86/platform branch of tip:
Commit-ID: ec2f16f180ae65b7c7179b4bb71af5fb2650f036
Gitweb: https://git.kernel.org/tip/ec2f16f180ae65b7c7179b4bb71af5fb2650f036
Author: Hans de Goede <[email protected]>
AuthorDate: Sat, 16 Sep 2023 15:06:53 +02:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Sun, 17 Sep 2023 09:52:51 +02:00
x86/platform/uv: Rework NMI "action" modparam handling
Rework NMI "action" modparam handling:
- Replace the uv_nmi_action string with an enum; and
- Use sysfs_match_string() for string parsing in param_set_action()
No change in functionality intended.
Suggested-by: Steve Wahl <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Tested-by: Steve Wahl <[email protected]>
Reviewed-by: Justin Stitt <[email protected]>
Reviewed-by: Steve Wahl <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/platform/uv/uv_nmi.c | 104 ++++++++++++++++++---------------
1 file changed, 57 insertions(+), 47 deletions(-)
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index 45d0c17..e03207d 100644
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -17,6 +17,7 @@
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/slab.h>
+#include <linux/string.h>
#include <linux/clocksource.h>
#include <asm/apic.h>
@@ -178,49 +179,56 @@ module_param_named(debug, uv_nmi_debug, int, 0644);
} while (0)
/* Valid NMI Actions */
-#define ACTION_LEN 16
-static struct nmi_action {
- char *action;
- char *desc;
-} valid_acts[] = {
- { "kdump", "do kernel crash dump" },
- { "dump", "dump process stack for each cpu" },
- { "ips", "dump Inst Ptr info for each cpu" },
- { "kdb", "enter KDB (needs kgdboc= assignment)" },
- { "kgdb", "enter KGDB (needs gdb target remote)" },
- { "health", "check if CPUs respond to NMI" },
+enum action_t {
+ nmi_act_kdump,
+ nmi_act_dump,
+ nmi_act_ips,
+ nmi_act_kdb,
+ nmi_act_kgdb,
+ nmi_act_health,
+ nmi_act_max
};
-typedef char action_t[ACTION_LEN];
-static action_t uv_nmi_action = { "dump" };
+
+static const char * const actions[nmi_act_max] = {
+ [nmi_act_kdump] = "kdump",
+ [nmi_act_dump] = "dump",
+ [nmi_act_ips] = "ips",
+ [nmi_act_kdb] = "kdb",
+ [nmi_act_kgdb] = "kgdb",
+ [nmi_act_health] = "health",
+};
+
+static const char * const actions_desc[nmi_act_max] = {
+ [nmi_act_kdump] = "do kernel crash dump",
+ [nmi_act_dump] = "dump process stack for each cpu",
+ [nmi_act_ips] = "dump Inst Ptr info for each cpu",
+ [nmi_act_kdb] = "enter KDB (needs kgdboc= assignment)",
+ [nmi_act_kgdb] = "enter KGDB (needs gdb target remote)",
+ [nmi_act_health] = "check if CPUs respond to NMI",
+};
+
+static enum action_t uv_nmi_action = nmi_act_dump;
static int param_get_action(char *buffer, const struct kernel_param *kp)
{
- return sprintf(buffer, "%s\n", uv_nmi_action);
+ return sprintf(buffer, "%s\n", actions[uv_nmi_action]);
}
static int param_set_action(const char *val, const struct kernel_param *kp)
{
- int i;
- int n = ARRAY_SIZE(valid_acts);
- char arg[ACTION_LEN];
-
- /* (remove possible '\n') */
- strscpy(arg, val, strnchrnul(val, sizeof(arg)-1, '\n') - val + 1);
-
- for (i = 0; i < n; i++)
- if (!strcmp(arg, valid_acts[i].action))
- break;
+ int i, n = ARRAY_SIZE(actions);
- if (i < n) {
- strscpy(uv_nmi_action, arg, sizeof(uv_nmi_action));
- pr_info("UV: New NMI action:%s\n", uv_nmi_action);
+ i = sysfs_match_string(actions, val);
+ if (i >= 0) {
+ uv_nmi_action = i;
+ pr_info("UV: New NMI action:%s\n", actions[i]);
return 0;
}
- pr_err("UV: Invalid NMI action:%s, valid actions are:\n", arg);
+ pr_err("UV: Invalid NMI action. Valid actions are:\n");
for (i = 0; i < n; i++)
- pr_err("UV: %-8s - %s\n",
- valid_acts[i].action, valid_acts[i].desc);
+ pr_err("UV: %-8s - %s\n", actions[i], actions_desc[i]);
+
return -EINVAL;
}
@@ -228,15 +236,10 @@ static const struct kernel_param_ops param_ops_action = {
.get = param_get_action,
.set = param_set_action,
};
-#define param_check_action(name, p) __param_check(name, p, action_t)
+#define param_check_action(name, p) __param_check(name, p, enum action_t)
module_param_named(action, uv_nmi_action, action, 0644);
-static inline bool uv_nmi_action_is(const char *action)
-{
- return (strncmp(uv_nmi_action, action, strlen(action)) == 0);
-}
-
/* Setup which NMI support is present in system */
static void uv_nmi_setup_mmrs(void)
{
@@ -727,10 +730,10 @@ static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs)
if (cpu == 0)
uv_nmi_dump_cpu_ip_hdr();
- if (current->pid != 0 || !uv_nmi_action_is("ips"))
+ if (current->pid != 0 || uv_nmi_action != nmi_act_ips)
uv_nmi_dump_cpu_ip(cpu, regs);
- if (uv_nmi_action_is("dump")) {
+ if (uv_nmi_action == nmi_act_dump) {
pr_info("UV:%sNMI process trace for CPU %d\n", dots, cpu);
show_regs(regs);
}
@@ -798,7 +801,7 @@ static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master)
int saved_console_loglevel = console_loglevel;
pr_alert("UV: tracing %s for %d CPUs from CPU %d\n",
- uv_nmi_action_is("ips") ? "IPs" : "processes",
+ uv_nmi_action == nmi_act_ips ? "IPs" : "processes",
atomic_read(&uv_nmi_cpus_in_nmi), cpu);
console_loglevel = uv_nmi_loglevel;
@@ -874,7 +877,7 @@ static inline int uv_nmi_kdb_reason(void)
static inline int uv_nmi_kdb_reason(void)
{
/* Ensure user is expecting to attach gdb remote */
- if (uv_nmi_action_is("kgdb"))
+ if (uv_nmi_action == nmi_act_kgdb)
return 0;
pr_err("UV: NMI error: KDB is not enabled in this kernel\n");
@@ -950,28 +953,35 @@ static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
master = (atomic_read(&uv_nmi_cpu) == cpu);
/* If NMI action is "kdump", then attempt to do it */
- if (uv_nmi_action_is("kdump")) {
+ if (uv_nmi_action == nmi_act_kdump) {
uv_nmi_kdump(cpu, master, regs);
/* Unexpected return, revert action to "dump" */
if (master)
- strscpy(uv_nmi_action, "dump", sizeof(uv_nmi_action));
+ uv_nmi_action = nmi_act_dump;
}
/* Pause as all CPU's enter the NMI handler */
uv_nmi_wait(master);
/* Process actions other than "kdump": */
- if (uv_nmi_action_is("health")) {
+ switch (uv_nmi_action) {
+ case nmi_act_health:
uv_nmi_action_health(cpu, regs, master);
- } else if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) {
+ break;
+ case nmi_act_ips:
+ case nmi_act_dump:
uv_nmi_dump_state(cpu, regs, master);
- } else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb")) {
+ break;
+ case nmi_act_kdb:
+ case nmi_act_kgdb:
uv_call_kgdb_kdb(cpu, regs, master);
- } else {
+ break;
+ default:
if (master)
- pr_alert("UV: unknown NMI action: %s\n", uv_nmi_action);
+ pr_alert("UV: unknown NMI action: %d\n", uv_nmi_action);
uv_nmi_sync_exit(master);
+ break;
}
/* Clear per_cpu "in_nmi" flag */