xnu-4903.241.1.tar.gz

[apple/xnu.git] / pexpert / i386 / pe_kprintf.c

diff --git a/pexpert/i386/pe_kprintf.c b/pexpert/i386/pe_kprintf.c
index 84855f63ec347780278cf2eba30da6a5090a83ce..d1d51da432897c998ee60b1bd00dfa548dbf80f1 100644 (file)
--- a/pexpert/i386/pe_kprintf.c
+++ b/pexpert/i386/pe_kprintf.c
@@ -34,12 +34,24 @@
 #include <pexpert/pexpert.h>
 #include <kern/debug.h>
 #include <kern/simple_lock.h>
+#include <i386/machine_cpu.h>
 #include <i386/mp.h>
+#include <machine/pal_routines.h>
+#include <i386/proc_reg.h>
+#include <os/log_private.h>
+#include <libkern/section_keywords.h>
 
 /* Globals */
 void (*PE_kputc)(char c);
 
-unsigned int disable_serial_output = TRUE;
+#if DEVELOPMENT || DEBUG 
+/* DEBUG kernel starts with true serial, but
+ * may later disable or switch to video
+ * console */
+SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = FALSE;
+#else
+SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = TRUE;
+#endif
 
 decl_simple_lock_data(static, kprintf_lock)
 
@@ -51,19 +63,31 @@ void PE_init_kprintf(boolean_t vm_initialized)
                panic("Platform Expert not initialized");
 
        if (!vm_initialized) {
+               unsigned int new_disable_serial_output = TRUE;
+
                simple_lock_init(&kprintf_lock, 0);
 
                if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
                        if (boot_arg & DB_KPRT)
-                               disable_serial_output = FALSE;
+                               new_disable_serial_output = FALSE;
 
-               if (!disable_serial_output && serial_init())
-                       PE_kputc = serial_putc;
+               /* If we are newly enabling serial, make sure we only
+                * call pal_serial_init() if our previous state was
+                * not enabled */
+               if (!new_disable_serial_output && (!disable_serial_output || pal_serial_init()))
+                       PE_kputc = pal_serial_putc;
                else
                        PE_kputc = cnputc;
+
+               disable_serial_output = new_disable_serial_output;
        }
 }
 
+#if CONFIG_NO_KPRINTF_STRINGS
+/* Prevent CPP from breaking the definition below */
+#undef kprintf
+#endif
+
 #ifdef MP_DEBUG
 static void _kprintf(const char *format, ...)
 {
@@ -79,23 +103,47 @@ static void _kprintf(const char *format, ...)
 #endif /* MP_DEBUG */
 
 static int cpu_last_locked = 0;
+
+__attribute__((noinline,not_tail_called))
 void kprintf(const char *fmt, ...)
 {
-       va_list   listp;
-       boolean_t state;
+       va_list    listp;
+       va_list    listp2;
+       boolean_t  state;
+       void      *caller = __builtin_return_address(0);
 
        if (!disable_serial_output) {
+               boolean_t early = FALSE;
+               if (rdmsr64(MSR_IA32_GS_BASE) == 0) {
+                       early = TRUE;
+               }
+               /* If PE_kputc has not yet been initialized, don't
+                * take any locks, just dump to serial */
+               if (!PE_kputc || early) {
+                       va_start(listp, fmt);
+                       va_copy(listp2, listp);
+
+                       _doprnt_log(fmt, &listp, pal_serial_putc, 16);
+                       va_end(listp);
+
+                       // If interrupts are enabled
+                       if (ml_get_interrupts_enabled()) {
+                               os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
+                       }
+                       va_end(listp2);
+                       return;
+               }
 
                /*
-                * Spin to get kprintf lock but re-enable interrupts while
-                * failing.
-                * This allows interrupts to be handled while waiting but
-                * interrupts are disabled once we have the lock.
+                * Spin to get kprintf lock but poll for incoming signals
+                * while interrupts are masked.
                 */
                state = ml_set_interrupts_enabled(FALSE);
+
+               pal_preemption_assert();
+
                while (!simple_lock_try(&kprintf_lock)) {
-                       ml_set_interrupts_enabled(state);
-                       ml_set_interrupts_enabled(FALSE);
+                       (void) cpu_signal_handler(NULL);
                }
 
                if (cpu_number() != cpu_last_locked) {
@@ -104,14 +152,31 @@ void kprintf(const char *fmt, ...)
                }
 
                va_start(listp, fmt);
+               va_copy(listp2, listp);
                _doprnt(fmt, &listp, PE_kputc, 16);
                va_end(listp);
 
                simple_unlock(&kprintf_lock);
                ml_set_interrupts_enabled(state);
+
+               // If interrupts are enabled
+               if (ml_get_interrupts_enabled()) {
+                       os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
+               }
+               va_end(listp2);
+
+       }
+       else {
+               if (ml_get_interrupts_enabled()) {
+                       va_start(listp, fmt);
+                       os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp, caller);
+                       va_end(listp);
+               }
        }
 }
 
+
+
 extern void kprintf_break_lock(void);
 void
 kprintf_break_lock(void)