Description:
* This patch provides an initial support for DWARF debug sections in XCOFF.
Tests:
* AIX: Build: SUCCESS
- build made by means of gmake.
ChangeLog:
* xcoff.c: Initial support for DWARF debug sections in XCOFF.
Cordialement,
Tony Reix
Bull - ATOS
IBM Coop Architect & Technical Leader
Office : +33 (0) 4 76 29 72 67
1 rue de Provence - 38432 Échirolles - France
www.atos.net
Index: libbacktrace/ChangeLog
===================================================================
--- libbacktrace/ChangeLog (revision 250777)
+++ libbacktrace/ChangeLog (working copy)
@@ -1,3 +1,7 @@
+2017-08-01 Tony Reix <tony.r...@atos.net>
+
+ * xcoff.c: Initial support for DWARF debug sections in XCOFF.
+
2017-07-28 Tony Reix <tony.r...@atos.net>
* xcoff.c: Don't leak a file descriptor if an archive is malformed.
Index: libbacktrace/xcoff.c
===================================================================
--- libbacktrace/xcoff.c (revision 250777)
+++ libbacktrace/xcoff.c (working copy)
@@ -124,9 +124,16 @@ typedef struct {
#endif /* BACKTRACE_XCOFF_SIZE != 32 */
+#define STYP_DWARF 0x10 /* DWARF debugging section. */
#define STYP_TEXT 0x20 /* Executable text (code) section. */
#define STYP_OVRFLO 0x8000 /* Line-number field overflow section. */
+#define SSUBTYP_DWINFO 0x10000 /* DWARF info section. */
+#define SSUBTYP_DWLINE 0x20000 /* DWARF line-number section. */
+#define SSUBTYP_DWARNGE 0x50000 /* DWARF aranges section. */
+#define SSUBTYP_DWABREV 0x60000 /* DWARF abbreviation section. */
+#define SSUBTYP_DWSTR 0x70000 /* DWARF strings section. */
+
/* XCOFF symbol. */
#define SYMNMLEN 8
@@ -367,7 +374,30 @@ struct xcoff_fileline_data
struct xcoff_line_vector vec;
};
+/* An index of DWARF sections we care about. */
+enum dwarf_section
+{
+ DWSECT_INFO,
+ DWSECT_LINE,
+ DWSECT_ABBREV,
+ DWSECT_RANGES,
+ DWSECT_STR,
+ DWSECT_MAX
+};
+
+/* Information we gather for the DWARF sections we care about. */
+
+struct dwsect_info
+{
+ /* Section file offset. */
+ off_t offset;
+ /* Section size. */
+ size_t size;
+ /* Section contents, after read from file. */
+ const unsigned char *data;
+};
+
/* A dummy callback function used when we can't find any debug info. */
static int
@@ -1056,6 +1086,7 @@ xcoff_add (struct backtrace_state *state, int desc
struct backtrace_view linenos_view;
struct backtrace_view syms_view;
struct backtrace_view str_view;
+ struct backtrace_view dwarf_view;
b_xcoff_filhdr fhdr;
const b_xcoff_scnhdr *sects;
const b_xcoff_scnhdr *stext;
@@ -1062,6 +1093,9 @@ xcoff_add (struct backtrace_state *state, int desc
uint64_t lnnoptr;
uint32_t nlnno;
off_t str_off;
+ off_t min_offset;
+ off_t max_offset;
+ struct dwsect_info dwsect[DWSECT_MAX];
size_t sects_size;
size_t syms_size;
int32_t str_size;
@@ -1069,6 +1103,7 @@ xcoff_add (struct backtrace_state *state, int desc
int linenos_view_valid;
int syms_view_valid;
int str_view_valid;
+ int dwarf_view_valid;
int magic_ok;
int i;
@@ -1078,7 +1113,10 @@ xcoff_add (struct backtrace_state *state, int desc
linenos_view_valid = 0;
syms_view_valid = 0;
str_view_valid = 0;
+ dwarf_view_valid = 0;
+ str_size = 0;
+
/* Map the XCOFF file header. */
if (!backtrace_get_view (state, descriptor, offset, sizeof (b_xcoff_filhdr),
error_callback, data, &fhdr_view))
@@ -1092,7 +1130,7 @@ xcoff_add (struct backtrace_state *state, int desc
if (!magic_ok)
{
if (exe)
- error_callback (data, "executable file is not XCOFF", 0);
+ error_callback (data, "executable file is not XCOFF", 0);
goto fail;
}
@@ -1114,8 +1152,8 @@ xcoff_add (struct backtrace_state *state, int desc
/* FIXME: assumes only one .text section. */
for (i = 0; i < fhdr.f_nscns; ++i)
- if ((sects[i].s_flags & 0xffff) == STYP_TEXT)
- break;
+ if ((sects[i].s_flags & 0xffff) == STYP_TEXT)
+ break;
if (i == fhdr.f_nscns)
goto fail;
@@ -1134,12 +1172,12 @@ xcoff_add (struct backtrace_state *state, int desc
/* Find the matching .ovrflo section. */
for (i = 0; i < fhdr.f_nscns; ++i)
{
- if (((sects[i].s_flags & 0xffff) == STYP_OVRFLO)
- && sects[i].s_nlnno == sntext)
- {
- nlnno = sects[i].s_vaddr;
- break;
- }
+ if (((sects[i].s_flags & 0xffff) == STYP_OVRFLO)
+ && sects[i].s_nlnno == sntext)
+ {
+ nlnno = sects[i].s_vaddr;
+ break;
+ }
}
}
#endif
@@ -1194,10 +1232,92 @@ xcoff_add (struct backtrace_state *state, int desc
xcoff_add_syminfo_data (state, sdata);
}
- /* Read the line number entries. */
+ /* Read all the DWARF sections in a single view, since they are
+ probably adjacent in the file. We never release this view. */
- if (fhdr.f_symptr != 0 && lnnoptr != 0)
+ min_offset = 0;
+ max_offset = 0;
+ memset (dwsect, 0, sizeof dwsect);
+ for (i = 0; i < fhdr.f_nscns; ++i)
{
+ off_t end;
+ int idx;
+
+ if ((sects[i].s_flags & 0xffff) != STYP_DWARF
+ || sects[i].s_size == 0)
+ continue;
+ /* Map DWARF section to array index. */
+ switch (sects[i].s_flags & 0xffff0000)
+ {
+ case SSUBTYP_DWINFO:
+ idx = DWSECT_INFO;
+ break;
+ case SSUBTYP_DWLINE:
+ idx = DWSECT_LINE;
+ break;
+ case SSUBTYP_DWABREV:
+ idx = DWSECT_ABBREV;
+ break;
+ case SSUBTYP_DWARNGE:
+ idx = DWSECT_RANGES;
+ break;
+ case SSUBTYP_DWSTR:
+ idx = DWSECT_STR;
+ break;
+ default:
+ continue;
+ }
+ if (min_offset == 0 || sects[i].s_scnptr < min_offset)
+ min_offset = sects[i].s_scnptr;
+ end = sects[i].s_scnptr + sects[i].s_size;
+ if (end > max_offset)
+ max_offset = end;
+ dwsect[idx].offset = sects[i].s_scnptr;
+ dwsect[idx].size = sects[i].s_size;
+ }
+ if (min_offset != 0 && max_offset != 0)
+ {
+ if (!backtrace_get_view (state, descriptor, offset + min_offset,
+ max_offset - min_offset,
+ error_callback, data, &dwarf_view))
+ goto fail;
+ dwarf_view_valid = 1;
+
+ for (i = 0; i < (int) DWSECT_MAX; ++i)
+ {
+ if (dwsect[i].offset == 0)
+ dwsect[i].data = NULL;
+ else
+ dwsect[i].data = ((const unsigned char *) dwarf_view.data
+ + (dwsect[i].offset - min_offset));
+ }
+
+ if (!backtrace_dwarf_add (state, 0,
+ dwsect[DWSECT_INFO].data,
+ dwsect[DWSECT_INFO].size,
+#if BACKTRACE_XCOFF_SIZE == 32
+ /* XXX workaround for broken lineoff */
+ dwsect[DWSECT_LINE].data - 4,
+#else
+ /* XXX workaround for broken lineoff */
+ dwsect[DWSECT_LINE].data - 12,
+#endif
+ dwsect[DWSECT_LINE].size,
+ dwsect[DWSECT_ABBREV].data,
+ dwsect[DWSECT_ABBREV].size,
+ dwsect[DWSECT_RANGES].data,
+ dwsect[DWSECT_RANGES].size,
+ dwsect[DWSECT_STR].data,
+ dwsect[DWSECT_STR].size,
+ 1, /* big endian */
+ error_callback, data, fileline_fn))
+ goto fail;
+ }
+
+ /* Read the XCOFF line number entries if DWARF sections not found. */
+
+ if (!dwarf_view_valid && fhdr.f_symptr != 0 && lnnoptr != 0)
+ {
size_t linenos_size = (size_t) nlnno * LINESZ;
if (!backtrace_get_view (state, descriptor, offset + lnnoptr,
@@ -1239,6 +1359,8 @@ xcoff_add (struct backtrace_state *state, int desc
backtrace_release_view (state, &syms_view, error_callback, data);
if (linenos_view_valid)
backtrace_release_view (state, &linenos_view, error_callback, data);
+ if (dwarf_view_valid)
+ backtrace_release_view (state, &dwarf_view, error_callback, data);
if (descriptor != -1 && offset == 0)
backtrace_close (descriptor, error_callback, data);
return 0;
