Copy changes from GCC:

2018-04-17  Ian Lance Taylor  <iant@golang.org>

	* backtrace.c (backtrace_full): When testing whether we can
	allocate memory, call mmap directly, and munmap the memory.

2018-04-04  Jakub Jelinek  <jakub@redhat.com>

	PR other/85161
	* elf.c (elf_zlib_fetch): Fix up predefined macro names in test for
	big endian, only use 32-bit loads if endianity macros are predefined
	and indicate big or little endian.

2018-02-15  Jakub Jelinek  <jakub@redhat.com>

	PR other/82368
	* elf.c (SHT_PROGBITS): Undefine and define.

2018-02-14  Jakub Jelinek  <jakub@redhat.com>

	PR other/82368
	* elf.c (EM_PPC64, EF_PPC64_ABI): Undefine and define.
	(struct elf_ppc64_opd_data): New type.
	(elf_initialize_syminfo): Add opd argument, handle symbols
	pointing into the PowerPC64 ELFv1 .opd section.
	(elf_add): Read .opd section on PowerPC64 ELFv1, pass pointer
	to structure with .opd data to elf_initialize_syminfo.

2018-01-19  Tony Reix  <tony.reix@atos.net>

	* xcoff.c (xcoff_incl_compare): New function.
	(xcoff_incl_search): New function.
	(xcoff_process_linenos): Use bsearch to find include file.
	(xcoff_initialize_fileline): Sort include file information.

Fixes ianlancetaylor#13

Author: ianlancetaylor

backtrace.c

@@ -32,12 +32,26 @@ POSSIBILITY OF SUCH DAMAGE.  */
 
 #include "config.h"
 
+#include <unistd.h>
 #include <sys/types.h>
 
+#if !BACKTRACE_USES_MALLOC
+#include <sys/mman.h>
+#endif
+
 #include "unwind.h"
 #include "backtrace.h"
+#include "backtrace-supported.h"
 #include "internal.h"
 
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
 /* The main backtrace_full routine.  */
 
 /* Data passed through _Unwind_Backtrace.  */
@@ -104,7 +118,6 @@ backtrace_full (struct backtrace_state *state, int skip,
 		backtrace_error_callback error_callback, void *data)
 {
   struct backtrace_data bdata;
-  void *p;
 
   bdata.skip = skip + 1;
   bdata.state = state;
@@ -113,16 +126,25 @@ backtrace_full (struct backtrace_state *state, int skip,
   bdata.data = data;
   bdata.ret = 0;
 
-  /* If we can't allocate any memory at all, don't try to produce
-     file/line information.  */
-  p = backtrace_alloc (state, 4096, NULL, NULL);
-  if (p == NULL)
-    bdata.can_alloc = 0;
-  else
-    {
-      backtrace_free (state, p, 4096, NULL, NULL);
-      bdata.can_alloc = 1;
-    }
+#if !BACKTRACE_USES_MALLOC
+  {
+    size_t pagesize;
+    void *page;
+
+    /* If we can't allocate any memory at all, don't try to produce
+       file/line information.  */
+    pagesize = getpagesize ();
+    page = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, 
+		 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    if (page == MAP_FAILED)
+      bdata.can_alloc = 0;
+    else
+      {
+	munmap (page, pagesize);
+	bdata.can_alloc = 1;
+      }
+  }
+#endif
 
   _Unwind_Backtrace (unwind, &bdata);
   return bdata.ret;

elf.c

@@ -165,9 +165,12 @@ dl_iterate_phdr (int (*callback) (struct dl_phdr_info *,
 #undef ELFDATA2MSB
 #undef EV_CURRENT
 #undef ET_DYN
+#undef EM_PPC64
+#undef EF_PPC64_ABI
 #undef SHN_LORESERVE
 #undef SHN_XINDEX
 #undef SHN_UNDEF
+#undef SHT_PROGBITS
 #undef SHT_SYMTAB
 #undef SHT_STRTAB
 #undef SHT_DYNSYM
@@ -245,6 +248,9 @@ typedef struct {
 
 #define ET_DYN 3
 
+#define EM_PPC64 21
+#define EF_PPC64_ABI 3
+
 typedef struct {
   b_elf_word	sh_name;		/* Section name, index in string tbl */
   b_elf_word	sh_type;		/* Type of section */
@@ -262,6 +268,7 @@ typedef struct {
 #define SHN_LORESERVE	0xFF00		/* Begin range of reserved indices */
 #define SHN_XINDEX	0xFFFF		/* Section index is held elsewhere */
 
+#define SHT_PROGBITS 1
 #define SHT_SYMTAB 2
 #define SHT_STRTAB 3
 #define SHT_DYNSYM 11
@@ -405,6 +412,20 @@ struct elf_syminfo_data
   size_t count;
 };
 
+/* Information about PowerPC64 ELFv1 .opd section.  */
+
+struct elf_ppc64_opd_data
+{
+  /* Address of the .opd section.  */
+  b_elf_addr addr;
+  /* Section data.  */
+  const char *data;
+  /* Size of the .opd section.  */
+  size_t size;
+  /* Corresponding section view.  */
+  struct backtrace_view view;
+};
+
 /* Compute the CRC-32 of BUF/LEN.  This uses the CRC used for
    .gnu_debuglink files.  */
 
@@ -569,7 +590,8 @@ elf_initialize_syminfo (struct backtrace_state *state,
 			const unsigned char *symtab_data, size_t symtab_size,
 			const unsigned char *strtab, size_t strtab_size,
 			backtrace_error_callback error_callback,
-			void *data, struct elf_syminfo_data *sdata)
+			void *data, struct elf_syminfo_data *sdata,
+			struct elf_ppc64_opd_data *opd)
 {
   size_t sym_count;
   const b_elf_sym *sym;
@@ -620,7 +642,17 @@ elf_initialize_syminfo (struct backtrace_state *state,
 	  return 0;
 	}
       elf_symbols[j].name = (const char *) strtab + sym->st_name;
-      elf_symbols[j].address = sym->st_value + base_address;
+      /* Special case PowerPC64 ELFv1 symbols in .opd section, if the symbol
+	 is a function descriptor, read the actual code address from the
+	 descriptor.  */
+      if (opd
+	  && sym->st_value >= opd->addr
+	  && sym->st_value < opd->addr + opd->size)
+	elf_symbols[j].address
+	  = *(const b_elf_addr *) (opd->data + (sym->st_value - opd->addr));
+      else
+	elf_symbols[j].address = sym->st_value;
+      elf_symbols[j].address += base_address;
       elf_symbols[j].size = sym->st_size;
       ++j;
     }
@@ -1054,12 +1086,19 @@ elf_zlib_fetch (const unsigned char **ppin, const unsigned char *pinend,
       return 0;
     }
 
+#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) \
+    && defined(__ORDER_BIG_ENDIAN__) \
+    && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ \
+        || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
   /* We've ensured that PIN is aligned.  */
   next = *(const uint32_t *)pin;
 
-#if __BYTE_ORDER == __ORDER_BIG_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
   next = __builtin_bswap32 (next);
 #endif
+#else
+  next = pin[0] | (pin[1] << 8) | (pin[2] << 16) | (pin[3] << 24);
+#endif
 
   val |= (uint64_t)next << bits;
   bits += 32;
@@ -2637,6 +2676,7 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
   int debug_view_valid;
   unsigned int using_debug_view;
   uint16_t *zdebug_table;
+  struct elf_ppc64_opd_data opd_data, *opd;
 
   if (!debuginfo)
     {
@@ -2655,6 +2695,7 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
   debuglink_name = NULL;
   debuglink_crc = 0;
   debug_view_valid = 0;
+  opd = NULL;
 
   if (!backtrace_get_view (state, descriptor, 0, sizeof ehdr, error_callback,
 			   data, &ehdr_view))
@@ -2857,6 +2898,23 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
 	      debuglink_crc = *(const uint32_t*)(debuglink_data + crc_offset);
 	    }
 	}
+
+      /* Read the .opd section on PowerPC64 ELFv1.  */
+      if (ehdr.e_machine == EM_PPC64
+	  && (ehdr.e_flags & EF_PPC64_ABI) < 2
+	  && shdr->sh_type == SHT_PROGBITS
+	  && strcmp (name, ".opd") == 0)
+	{
+	  if (!backtrace_get_view (state, descriptor, shdr->sh_offset,
+				   shdr->sh_size, error_callback, data,
+				   &opd_data.view))
+	    goto fail;
+
+	  opd = &opd_data;
+	  opd->addr = shdr->sh_addr;
+	  opd->data = (const char *) opd_data.view.data;
+	  opd->size = shdr->sh_size;
+	}
     }
 
   if (symtab_shndx == 0)
@@ -2898,7 +2956,7 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
       if (!elf_initialize_syminfo (state, base_address,
 				   symtab_view.data, symtab_shdr->sh_size,
 				   strtab_view.data, strtab_shdr->sh_size,
-				   error_callback, data, sdata))
+				   error_callback, data, sdata, opd))
 	{
 	  backtrace_free (state, sdata, sizeof *sdata, error_callback, data);
 	  goto fail;
@@ -2951,6 +3009,12 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
       buildid_view_valid = 0;
     }
 
+  if (opd)
+    {
+      backtrace_release_view (state, &opd->view, error_callback, data);
+      opd = NULL;
+    }
+
   if (debuglink_name != NULL)
     {
       int d;
@@ -3139,6 +3203,8 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
     backtrace_release_view (state, &buildid_view, error_callback, data);
   if (debug_view_valid)
     backtrace_release_view (state, &debug_view, error_callback, data);
+  if (opd)
+    backtrace_release_view (state, &opd->view, error_callback, data);
   if (descriptor != -1)
     backtrace_close (descriptor, error_callback, data);
   return 0;

xcoff.c

@@ -760,6 +760,40 @@ xcoff_fileline (struct backtrace_state *state, uintptr_t pc,
   return callback (data, pc, NULL, 0, NULL);
 }
 
+/* Compare struct xcoff_incl for qsort.  */
+
+static int
+xcoff_incl_compare (const void *v1, const void *v2)
+{
+  const struct xcoff_incl *in1 = (const struct xcoff_incl *) v1;
+  const struct xcoff_incl *in2 = (const struct xcoff_incl *) v2;
+
+  if (in1->begin < in2->begin)
+    return -1;
+  else if (in1->begin > in2->begin)
+    return 1;
+  else
+    return 0;
+}
+
+/* Find a lnnoptr in an include file.  */
+
+static int
+xcoff_incl_search (const void *vkey, const void *ventry)
+{
+  const uintptr_t *key = (const uintptr_t *) vkey;
+  const struct xcoff_incl *entry = (const struct xcoff_incl *) ventry;
+  uintptr_t lnno;
+
+  lnno = *key;
+  if (lnno < entry->begin)
+    return -1;
+  else if (lnno > entry->end)
+    return 1;
+  else
+    return 0;
+}
+
 /* Add a new mapping to the vector of line mappings that we are
    building.  Returns 1 on success, 0 on failure.  */
 
@@ -809,7 +843,6 @@ xcoff_process_linenos (struct backtrace_state *state, uintptr_t base_address,
   uintptr_t pc;
   uint32_t lnno;
   int begincl;
-  size_t i;
 
   aux = (const b_xcoff_auxent *) (fsym + 1);
   lnnoptr = aux->x_fcn.x_lnnoptr;
@@ -839,15 +872,13 @@ xcoff_process_linenos (struct backtrace_state *state, uintptr_t base_address,
       /* If part of a function other than the beginning comes from an
 	 include file, the line numbers are absolute, rather than
 	 relative to the beginning of the function.  */
-      for (i = 0; i < vec->count; ++i)
-	{
-	  incl = (struct xcoff_incl *) vec->vec.base + i;
-	  if (incl->begin <= lnnoptr && lnnoptr <= incl->end)
-	    break;
-	}
+      incl = (struct xcoff_incl *) bsearch (&lnnoptr, vec->vec.base,
+					    vec->count,
+					    sizeof (struct xcoff_incl),
+					    xcoff_incl_search);
       if (begincl == -1)
-	begincl = (i < vec->count);
-      if (i < vec->count)
+	begincl = incl != NULL;
+      if (incl != NULL)
 	{
 	  filename = incl->filename;
 	  if (begincl == 1)
@@ -935,6 +966,9 @@ xcoff_initialize_fileline (struct backtrace_state *state,
       i += asym->n_numaux;
     }
 
+  backtrace_qsort (vec.vec.base, vec.count,
+		   sizeof (struct xcoff_incl), xcoff_incl_compare);
+
   filename = NULL;
   fsym = NULL;
   for (i = 0; i < nsyms; ++i)