From f550e4692749a909d3f5453ef11b4c8ab2071070 Mon Sep 17 00:00:00 2001 From: "travis@sgi.com" Date: Wed, 25 Jan 2017 10:35:21 -0600 Subject: [PATCH] x86/platform/UV: Verify NMI action is valid, default is standard Verify that the NMI action being set is valid. The default NMI action changes from the non-standard 'kdb' to the more standard 'dump'. Signed-off-by: Mike Travis Reviewed-by: Russ Anderson Reviewed-by: Alex Thorlton Acked-by: Thomas Gleixner Acked-by: Dimitri Sivanich Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170125163517.922751779@asylum.americas.sgi.com Signed-off-by: Ingo Molnar --- arch/x86/platform/uv/uv_nmi.c | 69 +++++++++++++++++++++++++++++------ 1 file changed, 58 insertions(+), 11 deletions(-) diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c index 8a4aa5b3c11a..c10e00b2b2ee 100644 --- a/arch/x86/platform/uv/uv_nmi.c +++ b/arch/x86/platform/uv/uv_nmi.c @@ -169,17 +169,64 @@ module_param_named(debug, uv_nmi_debug, int, 0644); pr_info(fmt, ##__VA_ARGS__); \ } while (0) -/* - * Valid NMI Actions: - * "dump" - dump process stack for each cpu - * "ips" - dump IP info for each cpu - * "kdump" - do crash dump - * "kdb" - enter KDB (default) - * "kgdb" - enter KGDB - * "health" - check if CPUs respond to NMI - */ -static char uv_nmi_action[8] = "kdb"; -module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644); +/* 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" }, +}; +typedef char action_t[ACTION_LEN]; +static action_t uv_nmi_action = { "dump" }; + +static int param_get_action(char *buffer, const struct kernel_param *kp) +{ + return sprintf(buffer, "%s\n", 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], *p; + + /* (remove possible '\n') */ + strncpy(arg, val, ACTION_LEN - 1); + arg[ACTION_LEN - 1] = '\0'; + p = strchr(arg, '\n'); + if (p) + *p = '\0'; + + for (i = 0; i < n; i++) + if (!strcmp(arg, valid_acts[i].action)) + break; + + if (i < n) { + strcpy(uv_nmi_action, arg); + pr_info("UV: New NMI action:%s\n", uv_nmi_action); + return 0; + } + + pr_err("UV: Invalid NMI action:%s, valid actions are:\n", arg); + for (i = 0; i < n; i++) + pr_err("UV: %-8s - %s\n", + valid_acts[i].action, valid_acts[i].desc); + return -EINVAL; +} + +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) + +module_param_named(action, uv_nmi_action, action, 0644); static inline bool uv_nmi_action_is(const char *action) { -- 2.20.1