xnu-4570.20.62.tar.gz

[apple/xnu.git] / libkern / gen / OSDebug.cpp

diff --git a/libkern/gen/OSDebug.cpp b/libkern/gen/OSDebug.cpp
index f5bbec6837e408ec1d7863bfe42798ac985830a9..f112636313088c93fa1bbca021516b51d54c0aec 100644 (file)
--- a/libkern/gen/OSDebug.cpp
+++ b/libkern/gen/OSDebug.cpp
@@ -49,10 +49,18 @@ __BEGIN_DECLS
 extern vm_offset_t min_valid_stack_address(void);
 extern vm_offset_t max_valid_stack_address(void);
 
+// From osfmk/kern/printf.c
+extern boolean_t doprnt_hide_pointers;
+
 // From osfmk/kmod.c
-extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt);
+extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt, boolean_t doUnslide);
 
 extern addr64_t kvtophys(vm_offset_t va);
+#if __arm__ 
+extern int copyinframe(vm_address_t fp, char *frame);
+#elif defined(__arm64__)
+extern int copyinframe(vm_address_t fp, char *frame, boolean_t is64bit);
+#endif
 
 __END_DECLS
 
@@ -93,7 +101,7 @@ void
 OSReportWithBacktrace(const char *str, ...)
 {
     char buf[128];
-    void *bt[9];
+    void *bt[9] = {};
     const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
     va_list listp;
 
@@ -106,12 +114,15 @@ OSReportWithBacktrace(const char *str, ...)
 
     lck_mtx_lock(sOSReportLock);
     {
+        boolean_t old_doprnt_hide_pointers = doprnt_hide_pointers;
+        doprnt_hide_pointers = FALSE;
         printf("%s\nBacktrace 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", buf, 
             (unsigned long) VM_KERNEL_UNSLIDE(bt[2]), (unsigned long) VM_KERNEL_UNSLIDE(bt[3]), 
             (unsigned long) VM_KERNEL_UNSLIDE(bt[4]), (unsigned long) VM_KERNEL_UNSLIDE(bt[5]), 
             (unsigned long) VM_KERNEL_UNSLIDE(bt[6]), (unsigned long) VM_KERNEL_UNSLIDE(bt[7]), 
             (unsigned long) VM_KERNEL_UNSLIDE(bt[8]));
-        kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
+        kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2, TRUE);
+        doprnt_hide_pointers = old_doprnt_hide_pointers;
     }
     lck_mtx_unlock(sOSReportLock);
 }
@@ -166,6 +177,7 @@ OSPrintBacktrace(void)
 unsigned OSBacktrace(void **bt, unsigned maxAddrs)
 {
     unsigned frame;
+    if (!current_thread()) return 0;
 
 #if   __x86_64__
 #define SANE_x86_64_FRAME_SIZE (kernel_stack_size >> 1)
@@ -210,6 +222,42 @@ pad:
 
     for ( ; frame_index < maxAddrs; frame_index++)
            bt[frame_index] = (void *) 0;
+#elif __arm__ || __arm64__
+    uint32_t i = 0;
+    uintptr_t frameb[2];
+    uintptr_t fp = 0;
+    
+    // get the current frame pointer for this thread
+#if defined(__arm__)
+#define OSBacktraceFrameAlignOK(x) (((x) & 0x3) == 0)
+    __asm__ volatile("mov %0,r7" : "=r" (fp)); 
+#elif defined(__arm64__)
+#define OSBacktraceFrameAlignOK(x) (((x) & 0xf) == 0)
+    __asm__ volatile("mov %0, fp" : "=r" (fp)); 
+#else
+#error Unknown architecture.
+#endif
+    
+    // now crawl up the stack recording the link value of each frame
+    do {
+      // check bounds
+      if ((fp == 0) || (!OSBacktraceFrameAlignOK(fp)) || (fp > VM_MAX_KERNEL_ADDRESS) || (fp < VM_MIN_KERNEL_AND_KEXT_ADDRESS)) {
+       break;
+      }
+      // safely read frame
+#ifdef __arm64__
+      if (copyinframe(fp, (char*)frameb, TRUE) != 0) {
+#else
+      if (copyinframe(fp, (char*)frameb) != 0) {
+#endif
+       break;
+      }
+      
+      // No need to use copyin as this is always a kernel address, see check above
+      bt[i] = (void*)frameb[1];        // link register
+      fp = frameb[0]; 
+    } while (++i < maxAddrs);
+    frame= i;
 #else
 #error arch
 #endif