[patch] nto-procfs.c: Add to_xfer_partial

Aleksandar Ristovski
2009-06-11T20:31:29Z

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Hello,

This adds to_xfer_partial (auxv) capability to nto-procfs.

Thanks,

--
Aleksandar Ristovski
QNX Software Systems

ChangeLog:
* nto-procfs.c (procfs_xfer_partial): New function.
(init_procfs_ops): Register to_xfer_partial.
* nto-tdep.h (nto_read_auxv_from_initial_stack): Declare.
* nto-tdep.c (nto_read_auxv_from_initial_stack): Define.

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Index: gdb/nto-procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/nto-procfs.c,v
retrieving revision 1.45
diff -u -p -r1.45 nto-procfs.c
--- gdb/nto-procfs.c 7 Jun 2009 16:46:48 -0000 1.45
+++ gdb/nto-procfs.c 11 Jun 2009 20:27:35 -0000
@@ -774,6 +774,39 @@ procfs_xfer_memory (CORE_ADDR memaddr, g
return (nbytes);
}

+static LONGEST
+procfs_xfer_partial (struct target_ops *ops, enum target_object object,
+ const char *annex, gdb_byte *readbuf,
+ const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
+{
+ if (object == TARGET_OBJECT_AUXV
+ && readbuf)
+ {
+ int err;
+ CORE_ADDR initial_stack;
+ debug_process_t procinfo;
+
+ if (offset > 0)
+ return 0;
+
+ err = devctl (ctl_fd, DCMD_PROC_INFO, &procinfo, sizeof procinfo, 0);
+ if (err != EOK)
+ return -1;
+
+ /* Similar as in the case of a core file, we read auxv from
+ initial_stack. */
+ initial_stack = procinfo.initial_stack;
+
+ /* procfs is always 'self-hosted', no byte-order manipulation. */
+ return nto_read_auxv_from_initial_stack (initial_stack, readbuf, len);
+ }
+
+ if (ops->beneath && ops->beneath->to_xfer_partial)
+ return ops->beneath->to_xfer_partial (ops, object, annex, readbuf,
+ writebuf, offset, len);
+ return -1;
+}
+
/* Take a program previously attached to and detaches it.
The program resumes execution and will no longer stop
on signals, etc. We'd better not have left any breakpoints
@@ -1303,6 +1336,7 @@ init_procfs_ops (void)
procfs_ops.to_store_registers = procfs_store_registers;
procfs_ops.to_prepare_to_store = procfs_prepare_to_store;
procfs_ops.deprecated_xfer_memory = procfs_xfer_memory;
+ procfs_ops.to_xfer_partial = procfs_xfer_partial;
procfs_ops.to_files_info = procfs_files_info;
procfs_ops.to_insert_breakpoint = procfs_insert_breakpoint;
procfs_ops.to_remove_breakpoint = procfs_remove_breakpoint;
Index: gdb/nto-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/nto-tdep.h,v
retrieving revision 1.15
diff -u -p -r1.15 nto-tdep.h
--- gdb/nto-tdep.h 11 Jun 2009 19:29:00 -0000 1.15
+++ gdb/nto-tdep.h 11 Jun 2009 20:27:35 -0000
@@ -156,3 +156,7 @@ enum gdb_osabi nto_elf_osabi_sniffer (bf
int nto_in_dynsym_resolve_code (CORE_ADDR pc);

+LONGEST nto_read_auxv_from_initial_stack (CORE_ADDR inital_stack,
+ gdb_byte *readbuf,
+ LONGEST len);
+
#endif
Index: gdb/nto-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/nto-tdep.c,v
retrieving revision 1.33
diff -u -p -r1.33 nto-tdep.c
--- gdb/nto-tdep.c 11 Jun 2009 19:29:00 -0000 1.33
+++ gdb/nto-tdep.c 11 Jun 2009 20:27:35 -0000
@@ -385,6 +364,62 @@ nto_initialize_signals (void)
#endif
}

+LONGEST
+nto_read_auxv_from_initial_stack (CORE_ADDR initial_stack, gdb_byte *readbuf,
+ LONGEST len)
+{
+ int data_ofs = 0;
+ int anint32;
+ LONGEST len_read = 0;
+ gdb_byte *panint32 = (gdb_byte*)&anint32;
+ gdb_byte *buff;
+
+ /* Skip over argc, argv and envp... (see comment in ldd.c) */
+ if (target_read_memory (initial_stack + data_ofs, panint32, 4) != 0)
+ return 0;
+
+ anint32 = extract_unsigned_integer (panint32, sizeof (anint32));
+
+ /* Size of pointer is assumed to be 4 bytes (32 bit arch. ) */
+ data_ofs += (anint32 + 2) * 4; /* + 2 comes from argc itself and
+ NULL terminating pointer in argv */
+
+ /* Now loop over env table: */
+ while (target_read_memory (initial_stack + data_ofs, panint32, 4) == 0)
+ {
+ anint32 = extract_signed_integer (panint32, sizeof (anint32));
+ data_ofs += 4;
+ if (anint32 == 0)
+ break;
+ }
+ initial_stack += data_ofs;
+
+ memset (readbuf, 0, len);
+ buff = readbuf;
+ while (len_read <= len-8)
+ {
+ /* For 32-bit architecture, size of auxv_t is 8 bytes. */
+
+ /* Search backwards until we have read AT_PHDR (num. 3),
+ AT_PHENT (num 4), AT_PHNUM (num 5) */
+ if (target_read_memory (initial_stack, buff, 8)
+ == 0)
+ {
+ int a_type = extract_signed_integer (buff, sizeof (a_type));
+ if (a_type != AT_NULL)
+ {
+ buff += 8;
+ len_read += 8;
+ }
+ if (a_type == AT_PHNUM) /* That's all we need. */
+ break;
+ initial_stack += 8;
+ }
+ else
+ break;
+ }
+ return len_read;
+}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_nto_tdep;