Merge tag 'hardening-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - stackleak: Use str_enabled_disabled() helper (Thorsten Blum)

 - Document GCC INIT_STACK_ALL_PATTERN behavior (Geert Uytterhoeven)

 - Add task_prctl_unknown tracepoint (Marco Elver)

* tag 'hardening-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  hardening: Document INIT_STACK_ALL_PATTERN behavior with GCC
  stackleak: Use str_enabled_disabled() helper in stack_erasing_sysctl()
  tracing: Remove pid in task_rename tracing output
  tracing: Add task_prctl_unknown tracepoint

Author: torvalds

include/trace/events/task.h

@@ -38,22 +38,56 @@ TRACE_EVENT(task_rename,
 	TP_ARGS(task, comm),
 
 	TP_STRUCT__entry(
-		__field(	pid_t,	pid)
 		__array(	char, oldcomm,  TASK_COMM_LEN)
 		__array(	char, newcomm,  TASK_COMM_LEN)
 		__field(	short,	oom_score_adj)
 	),
 
 	TP_fast_assign(
-		__entry->pid = task->pid;
 		memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
 		strscpy(entry->newcomm, comm, TASK_COMM_LEN);
 		__entry->oom_score_adj = task->signal->oom_score_adj;
 	),
 
-	TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%hd",
-		__entry->pid, __entry->oldcomm,
-		__entry->newcomm, __entry->oom_score_adj)
+	TP_printk("oldcomm=%s newcomm=%s oom_score_adj=%hd",
+		  __entry->oldcomm, __entry->newcomm, __entry->oom_score_adj)
+);
+
+/**
+ * task_prctl_unknown - called on unknown prctl() option
+ * @option:	option passed
+ * @arg2:	arg2 passed
+ * @arg3:	arg3 passed
+ * @arg4:	arg4 passed
+ * @arg5:	arg5 passed
+ *
+ * Called on an unknown prctl() option.
+ */
+TRACE_EVENT(task_prctl_unknown,
+
+	TP_PROTO(int option, unsigned long arg2, unsigned long arg3,
+		 unsigned long arg4, unsigned long arg5),
+
+	TP_ARGS(option, arg2, arg3, arg4, arg5),
+
+	TP_STRUCT__entry(
+		__field(	int,		option)
+		__field(	unsigned long,	arg2)
+		__field(	unsigned long,	arg3)
+		__field(	unsigned long,	arg4)
+		__field(	unsigned long,	arg5)
+	),
+
+	TP_fast_assign(
+		__entry->option = option;
+		__entry->arg2 = arg2;
+		__entry->arg3 = arg3;
+		__entry->arg4 = arg4;
+		__entry->arg5 = arg5;
+	),
+
+	TP_printk("option=%d arg2=%ld arg3=%ld arg4=%ld arg5=%ld",
+		  __entry->option, __entry->arg2, __entry->arg3, __entry->arg4, __entry->arg5)
 );
 
 #endif

kernel/stackleak.c

@@ -15,6 +15,7 @@
 
 #ifdef CONFIG_STACKLEAK_RUNTIME_DISABLE
 #include <linux/jump_label.h>
+#include <linux/string_choices.h>
 #include <linux/sysctl.h>
 #include <linux/init.h>
 
@@ -41,7 +42,7 @@ static int stack_erasing_sysctl(const struct ctl_table *table, int write,
 		static_branch_enable(&stack_erasing_bypass);
 
 	pr_warn("stackleak: kernel stack erasing is %s\n",
-					state ? "enabled" : "disabled");
+					str_enabled_disabled(state));
 	return ret;
 }
 static struct ctl_table stackleak_sysctls[] = {

kernel/sys.c

@@ -75,6 +75,8 @@
 #include <asm/io.h>
 #include <asm/unistd.h>
 
+#include <trace/events/task.h>
+
 #include "uid16.h"
 
 #ifndef SET_UNALIGN_CTL
@@ -2810,6 +2812,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 		error = arch_lock_shadow_stack_status(me, arg2);
 		break;
 	default:
+		trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);
 		error = -EINVAL;
 		break;
 	}

security/Kconfig.hardening

@@ -127,6 +127,7 @@ choice
 		  repeating for all types and padding except float and double
 		  which use 0xFF repeating (-NaN). Clang on 32-bit uses 0xFF
 		  repeating for all types and padding.
+		  GCC uses 0xFE repeating for all types, and zero for padding.
 
 	config INIT_STACK_ALL_ZERO
 		bool "zero-init everything (strongest and safest)"