Merging upstream version 6.9.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 8 insertions, 33 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index e1b992652a..adf99c05ad 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -34,7 +34,7 @@
 #include <linux/security.h>
 #include <linux/memblock.h>
 #include <linux/syscalls.h>
-#include <linux/crash_core.h>
+#include <linux/vmcore_info.h>
 #include <linux/ratelimit.h>
 #include <linux/kmsg_dump.h>
 #include <linux/syslog.h>
@@ -462,12 +462,6 @@ static int console_msg_format = MSG_FORMAT_DEFAULT;
 static DEFINE_MUTEX(syslog_lock);
 
 #ifdef CONFIG_PRINTK
-/*
- * During panic, heavy printk by other CPUs can delay the
- * panic and risk deadlock on console resources.
- */
-static int __read_mostly suppress_panic_printk;
-
 DECLARE_WAIT_QUEUE_HEAD(log_wait);
 /* All 3 protected by @syslog_lock. */
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
@@ -621,17 +615,6 @@ static int check_syslog_permissions(int type, int source)
 	if (syslog_action_restricted(type)) {
 		if (capable(CAP_SYSLOG))
 			goto ok;
-		/*
-		 * For historical reasons, accept CAP_SYS_ADMIN too, with
-		 * a warning.
-		 */
-		if (capable(CAP_SYS_ADMIN)) {
-			pr_warn_once("%s (%d): Attempt to access syslog with "
-				     "CAP_SYS_ADMIN but no CAP_SYSLOG "
-				     "(deprecated).\n",
-				 current->comm, task_pid_nr(current));
-			goto ok;
-		}
 		return -EPERM;
 	}
 ok:
@@ -974,7 +957,7 @@ const struct file_operations kmsg_fops = {
 	.release = devkmsg_release,
 };
 
-#ifdef CONFIG_CRASH_CORE
+#ifdef CONFIG_VMCORE_INFO
 /*
  * This appends the listed symbols to /proc/vmcore
  *
@@ -2328,7 +2311,12 @@ asmlinkage int vprintk_emit(int facility, int level,
 	if (unlikely(suppress_printk))
 		return 0;
 
-	if (unlikely(suppress_panic_printk) && other_cpu_in_panic())
+	/*
+	 * The messages on the panic CPU are the most important. If
+	 * non-panic CPUs are generating any messages, they will be
+	 * silently dropped.
+	 */
+	if (other_cpu_in_panic())
 		return 0;
 
 	if (level == LOGLEVEL_SCHED) {
@@ -2813,8 +2801,6 @@ void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped)
 bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 			     bool is_extended, bool may_suppress)
 {
-	static int panic_console_dropped;
-
 	struct printk_buffers *pbufs = pmsg->pbufs;
 	const size_t scratchbuf_sz = sizeof(pbufs->scratchbuf);
 	const size_t outbuf_sz = sizeof(pbufs->outbuf);
@@ -2842,17 +2828,6 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 	pmsg->seq = r.info->seq;
 	pmsg->dropped = r.info->seq - seq;
 
-	/*
-	 * Check for dropped messages in panic here so that printk
-	 * suppression can occur as early as possible if necessary.
-	 */
-	if (pmsg->dropped &&
-	    panic_in_progress() &&
-	    panic_console_dropped++ > 10) {
-		suppress_panic_printk = 1;
-		pr_warn_once("Too many dropped messages. Suppress messages on non-panic CPUs to prevent livelock.\n");
-	}
-
 	/* Skip record that has level above the console loglevel. */
 	if (may_suppress && suppress_message_printing(r.info->level))
 		goto out;