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Re: [rfc/rfa] Retrieve libraries from remote target
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: eliz at gnu dot org
- Cc: gdb-patches at sourceware dot org, drow at false dot org
- Date: Thu, 14 Aug 2008 22:23:19 +0200 (CEST)
- Subject: Re: [rfc/rfa] Retrieve libraries from remote target
Eli Zaretskii wrote:
> As written, the sentence in effect says that it's GDB who uses the
> `remote:' prefix, which is probably not what you mean.
Indeed, thanks for catching this!
> Other than that, the doco patches are approved.
Thanks! Here's an updated version including those changes.
Bye,
Ulrich
ChangeLog:
* remote.h (remote_filename_p, remote_bfd_open): Add prototypes.
* remote.c (remote_bfd_iovec_open, remote_bfd_iovec_close,
remote_bfd_iovec_pread, remote_bfd_iovec_stat, remote_filename_p,
remote_bfd_open): New functions.
(remote_hostio_send_command): Fail safely if remote connection
is not set up.
* solist.h (solib_open): Remove prototype.
(solib_bfd_open): Add prototype.
* solib.c: Include "remote.h".
(solib_open): Remove, replace by ...
(solib_bfd_open): ... this new function. Handle remote BFDs.
(solib_map_sections): Replace solib_open by solib_bfd_open.
* solib-frv.c: Include "exceptions.h".
(enable_break2): Replace solib_open by solib_bfd_open.
* solib-svr4.c: Include "exceptions.h".
(enable_break): Replace solib_open by solib_bfd_open.
* symfile.c: Include "remote.h".
(build_id_verify): Handle remote BFDs.
(separate_debug_file_exists): Use BFD to access file. Handle
remote BFDs.
(symfile_bfd_open): Handle remote BFDs.
(reread_symbols): Handle remote BFDs.
* NEWS: Mention "remote:" argument prefix to "set sysroot".
doc/ChangeLog:
* gdb.texinfo (Commands to Specify Files): Document "remote:"
argument prefix to "set sysroot".
diff -urNp gdb-orig/gdb/doc/gdb.texinfo gdb-head/gdb/doc/gdb.texinfo
--- gdb-orig/gdb/doc/gdb.texinfo 2008-08-14 17:55:46.556444105 +0200
+++ gdb-head/gdb/doc/gdb.texinfo 2008-08-14 22:16:37.951684794 +0200
@@ -12595,8 +12595,11 @@ library events happen.
@end table
Shared libraries are also supported in many cross or remote debugging
-configurations. A copy of the target's libraries need to be present on the
-host system; they need to be the same as the target libraries, although the
+configurations. @value{GDBN} needs to have access to the target's libraries;
+this can be accomplished either by providing copies of the libraries
+on the host system, or by asking @value{GDBN} to automatically retrieve the
+libraries from the target. If copies of the target libraries are
+provided, they need to be the same as the target libraries, although the
copies on the target can be stripped as long as the copies on the host are
not.
@@ -12620,6 +12623,16 @@ libraries, they need to be laid out in t
the target, with e.g.@: a @file{/lib} and @file{/usr/lib} hierarchy
under @var{path}.
+If @var{path} starts with the sequence @file{remote:}, @value{GDBN} will
+retrieve the target libraries from the remote system. This is only
+supported when using a remote target that supports the @code{remote get}
+command (@pxref{File Transfer,,Sending files to a remote system}).
+The part of @var{path} following the initial @file{remote:}
+(if present) is used as system root prefix on the remote file system.
+@footnote{If you want to specify a local system root using a directory
+that happens to be named @file{remote:}, you need to use some equivalent
+variant of the name like @file{./remote:}.}
+
The @code{set solib-absolute-prefix} command is an alias for @code{set
sysroot}.
diff -urNp gdb-orig/gdb/NEWS gdb-head/gdb/NEWS
--- gdb-orig/gdb/NEWS 2008-08-14 17:55:46.584440094 +0200
+++ gdb-head/gdb/NEWS 2008-08-14 22:17:40.809110194 +0200
@@ -3,6 +3,11 @@
*** Changes since GDB 6.8
+* GDB now supports automatic retrieval of shared library files from
+remote targets. To use this feature, specify a system root that begins
+with the `remote:' prefix, either via the `set sysroot' command or via
+the `--with-sysroot' configure-time option.
+
* Commands `set debug-file-directory', `set solib-search-path' and `set args'
now complete on file names.
diff -urNp gdb-orig/gdb/remote.c gdb-head/gdb/remote.c
--- gdb-orig/gdb/remote.c 2008-08-14 22:09:22.693026189 +0200
+++ gdb-head/gdb/remote.c 2008-08-14 22:09:06.573811367 +0200
@@ -6695,7 +6695,8 @@ remote_hostio_send_command (int command_
int ret, bytes_read;
char *attachment_tmp;
- if (remote_protocol_packets[which_packet].support == PACKET_DISABLE)
+ if (!remote_desc
+ || remote_protocol_packets[which_packet].support == PACKET_DISABLE)
{
*remote_errno = FILEIO_ENOSYS;
return -1;
@@ -6959,6 +6960,97 @@ remote_hostio_close_cleanup (void *opaqu
remote_hostio_close (fd, &remote_errno);
}
+
+static void *
+remote_bfd_iovec_open (struct bfd *abfd, void *open_closure)
+{
+ const char *filename = bfd_get_filename (abfd);
+ int fd, remote_errno;
+ int *stream;
+
+ gdb_assert (remote_filename_p (filename));
+
+ fd = remote_hostio_open (filename + 7, FILEIO_O_RDONLY, 0, &remote_errno);
+ if (fd == -1)
+ {
+ errno = remote_fileio_errno_to_host (remote_errno);
+ bfd_set_error (bfd_error_system_call);
+ return NULL;
+ }
+
+ stream = xmalloc (sizeof (int));
+ *stream = fd;
+ return stream;
+}
+
+static int
+remote_bfd_iovec_close (struct bfd *abfd, void *stream)
+{
+ int fd = *(int *)stream;
+ int remote_errno;
+
+ xfree (stream);
+
+ /* Ignore errors on close; these may happen if the remote
+ connection was already torn down. */
+ remote_hostio_close (fd, &remote_errno);
+
+ return 1;
+}
+
+static file_ptr
+remote_bfd_iovec_pread (struct bfd *abfd, void *stream, void *buf,
+ file_ptr nbytes, file_ptr offset)
+{
+ int fd = *(int *)stream;
+ int remote_errno;
+ file_ptr pos, bytes;
+
+ pos = 0;
+ while (nbytes > pos)
+ {
+ bytes = remote_hostio_pread (fd, (char *)buf + pos, nbytes - pos,
+ offset + pos, &remote_errno);
+ if (bytes == 0)
+ /* Success, but no bytes, means end-of-file. */
+ break;
+ if (bytes == -1)
+ {
+ errno = remote_fileio_errno_to_host (remote_errno);
+ bfd_set_error (bfd_error_system_call);
+ return -1;
+ }
+
+ pos += bytes;
+ }
+
+ return pos;
+}
+
+static int
+remote_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb)
+{
+ /* FIXME: We should probably implement remote_hostio_stat. */
+ sb->st_size = INT_MAX;
+ return 0;
+}
+
+int
+remote_filename_p (const char *filename)
+{
+ return strncmp (filename, "remote:", 7) == 0;
+}
+
+bfd *
+remote_bfd_open (const char *remote_file, const char *target)
+{
+ return bfd_openr_iovec (remote_file, target,
+ remote_bfd_iovec_open, NULL,
+ remote_bfd_iovec_pread,
+ remote_bfd_iovec_close,
+ remote_bfd_iovec_stat);
+}
+
void
remote_file_put (const char *local_file, const char *remote_file, int from_tty)
{
diff -urNp gdb-orig/gdb/remote.h gdb-head/gdb/remote.h
--- gdb-orig/gdb/remote.h 2008-08-14 17:55:46.634432932 +0200
+++ gdb-head/gdb/remote.h 2008-08-14 22:09:06.580810364 +0200
@@ -73,4 +73,8 @@ void remote_file_get (const char *remote
int from_tty);
void remote_file_delete (const char *remote_file, int from_tty);
+bfd *remote_bfd_open (const char *remote_file, const char *target);
+
+int remote_filename_p (const char *filename);
+
#endif
diff -urNp gdb-orig/gdb/solib.c gdb-head/gdb/solib.c
--- gdb-orig/gdb/solib.c 2008-08-14 22:09:22.706024326 +0200
+++ gdb-head/gdb/solib.c 2008-08-14 22:09:06.592808644 +0200
@@ -44,6 +44,7 @@
#include "solist.h"
#include "observer.h"
#include "readline/readline.h"
+#include "remote.h"
/* Architecture-specific operations. */
@@ -106,11 +107,11 @@ The search path for loading non-absolute
GLOBAL FUNCTION
- solib_open -- Find a shared library file and open it.
+ solib_bfd_open -- Find a shared library file and open BFD for it.
SYNOPSIS
- int solib_open (char *in_patname, char **found_pathname);
+ struct bfd *solib_open (char *in_pathname);
DESCRIPTION
@@ -137,16 +138,17 @@ The search path for loading non-absolute
RETURNS
- file handle for opened solib, or -1 for failure. */
+ BFD file handle for opened solib; throws error on failure. */
-int
-solib_open (char *in_pathname, char **found_pathname)
+bfd *
+solib_bfd_open (char *in_pathname)
{
struct target_so_ops *ops = solib_ops (target_gdbarch);
int found_file = -1;
char *temp_pathname = NULL;
char *p = in_pathname;
int gdb_sysroot_is_empty;
+ bfd *abfd;
gdb_sysroot_is_empty = (gdb_sysroot == NULL || *gdb_sysroot == 0);
@@ -168,6 +170,29 @@ solib_open (char *in_pathname, char **fo
strcat (temp_pathname, in_pathname);
}
+ /* Handle remote files. */
+ if (remote_filename_p (temp_pathname))
+ {
+ temp_pathname = xstrdup (temp_pathname);
+ abfd = remote_bfd_open (temp_pathname, gnutarget);
+ if (!abfd)
+ {
+ make_cleanup (xfree, temp_pathname);
+ error (_("Could not open `%s' as an executable file: %s"),
+ temp_pathname, bfd_errmsg (bfd_get_error ()));
+ }
+
+ if (!bfd_check_format (abfd, bfd_object))
+ {
+ bfd_close (abfd);
+ make_cleanup (xfree, temp_pathname);
+ error (_("`%s': not in executable format: %s"),
+ temp_pathname, bfd_errmsg (bfd_get_error ()));
+ }
+
+ return abfd;
+ }
+
/* Now see if we can open it. */
found_file = open (temp_pathname, O_RDONLY | O_BINARY, 0);
@@ -228,16 +253,30 @@ solib_open (char *in_pathname, char **fo
OPF_TRY_CWD_FIRST, in_pathname, O_RDONLY | O_BINARY, 0,
&temp_pathname);
- /* Done. If not found, tough luck. Return found_file and
- (optionally) found_pathname. */
- if (temp_pathname)
+ /* Done. If still not found, error. */
+ if (found_file < 0)
+ perror_with_name (in_pathname);
+
+ /* Leave temp_pathname allocated. abfd->name will point to it. */
+ abfd = bfd_fopen (temp_pathname, gnutarget, FOPEN_RB, found_file);
+ if (!abfd)
{
- if (found_pathname != NULL)
- *found_pathname = temp_pathname;
- else
- xfree (temp_pathname);
+ close (found_file);
+ make_cleanup (xfree, temp_pathname);
+ error (_("Could not open `%s' as an executable file: %s"),
+ temp_pathname, bfd_errmsg (bfd_get_error ()));
+ }
+
+ if (!bfd_check_format (abfd, bfd_object))
+ {
+ bfd_close (abfd);
+ make_cleanup (xfree, temp_pathname);
+ error (_("`%s': not in executable format: %s"),
+ temp_pathname, bfd_errmsg (bfd_get_error ()));
}
- return found_file;
+
+ bfd_set_cacheable (abfd, 1);
+ return abfd;
}
@@ -273,46 +312,24 @@ solib_map_sections (void *arg)
{
struct so_list *so = (struct so_list *) arg; /* catch_errors bogon */
char *filename;
- char *scratch_pathname;
- int scratch_chan;
struct section_table *p;
struct cleanup *old_chain;
bfd *abfd;
filename = tilde_expand (so->so_name);
-
old_chain = make_cleanup (xfree, filename);
- scratch_chan = solib_open (filename, &scratch_pathname);
-
- if (scratch_chan < 0)
- {
- perror_with_name (filename);
- }
-
- /* Leave scratch_pathname allocated. abfd->name will point to it. */
- abfd = bfd_fopen (scratch_pathname, gnutarget, FOPEN_RB, scratch_chan);
- if (!abfd)
- {
- close (scratch_chan);
- error (_("Could not open `%s' as an executable file: %s"),
- scratch_pathname, bfd_errmsg (bfd_get_error ()));
- }
+ abfd = solib_bfd_open (filename);
+ do_cleanups (old_chain);
/* Leave bfd open, core_xfer_memory and "info files" need it. */
so->abfd = abfd;
- bfd_set_cacheable (abfd, 1);
/* copy full path name into so_name, so that later symbol_file_add
can find it */
- if (strlen (scratch_pathname) >= SO_NAME_MAX_PATH_SIZE)
- error (_("Full path name length of shared library exceeds SO_NAME_MAX_PATH_SIZE in so_list structure."));
- strcpy (so->so_name, scratch_pathname);
+ if (strlen (bfd_get_filename (abfd)) >= SO_NAME_MAX_PATH_SIZE)
+ error (_("Shared library file name is too long."));
+ strcpy (so->so_name, bfd_get_filename (abfd));
- if (!bfd_check_format (abfd, bfd_object))
- {
- error (_("\"%s\": not in executable format: %s."),
- scratch_pathname, bfd_errmsg (bfd_get_error ()));
- }
if (build_section_table (abfd, &so->sections, &so->sections_end))
{
error (_("Can't find the file sections in `%s': %s"),
@@ -339,9 +356,6 @@ solib_map_sections (void *arg)
}
}
- /* Free the file names, close the file now. */
- do_cleanups (old_chain);
-
return (1);
}
diff -urNp gdb-orig/gdb/solib-frv.c gdb-head/gdb/solib-frv.c
--- gdb-orig/gdb/solib-frv.c 2008-08-14 22:09:22.718022606 +0200
+++ gdb-head/gdb/solib-frv.c 2008-08-14 22:09:06.604806924 +0200
@@ -30,6 +30,7 @@
#include "command.h"
#include "gdbcmd.h"
#include "elf/frv.h"
+#include "exceptions.h"
/* Flag which indicates whether internal debug messages should be printed. */
static int solib_frv_debug;
@@ -645,12 +646,11 @@ enable_break2 (void)
unsigned int interp_sect_size;
gdb_byte *buf;
bfd *tmp_bfd = NULL;
- int tmp_fd = -1;
- char *tmp_pathname = NULL;
int status;
CORE_ADDR addr, interp_loadmap_addr;
gdb_byte addr_buf[FRV_PTR_SIZE];
struct int_elf32_fdpic_loadmap *ldm;
+ volatile struct gdb_exception ex;
/* Read the contents of the .interp section into a local buffer;
the contents specify the dynamic linker this program uses. */
@@ -668,25 +668,16 @@ enable_break2 (void)
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
- tmp_fd = solib_open (buf, &tmp_pathname);
- if (tmp_fd >= 0)
- tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
-
+ TRY_CATCH (ex, RETURN_MASK_ALL)
+ {
+ tmp_bfd = solib_bfd_open (buf);
+ }
if (tmp_bfd == NULL)
{
enable_break_failure_warning ();
return 0;
}
- /* Make sure the dynamic linker is really a useful object. */
- if (!bfd_check_format (tmp_bfd, bfd_object))
- {
- warning (_("Unable to grok dynamic linker %s as an object file"), buf);
- enable_break_failure_warning ();
- bfd_close (tmp_bfd);
- return 0;
- }
-
status = frv_fdpic_loadmap_addresses (target_gdbarch,
&interp_loadmap_addr, 0);
if (status < 0)
diff -urNp gdb-orig/gdb/solib-svr4.c gdb-head/gdb/solib-svr4.c
--- gdb-orig/gdb/solib-svr4.c 2008-08-14 22:09:22.741019309 +0200
+++ gdb-head/gdb/solib-svr4.c 2008-08-14 22:09:06.619804774 +0200
@@ -42,6 +42,7 @@
#include "elf-bfd.h"
#include "exec.h"
#include "auxv.h"
+#include "exceptions.h"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
@@ -1038,8 +1039,7 @@ enable_break (void)
struct so_list *so;
bfd *tmp_bfd = NULL;
struct target_ops *tmp_bfd_target;
- int tmp_fd = -1;
- char *tmp_pathname = NULL;
+ volatile struct gdb_exception ex;
/* Read the contents of the .interp section into a local buffer;
the contents specify the dynamic linker this program uses. */
@@ -1058,21 +1058,13 @@ enable_break (void)
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
- tmp_fd = solib_open (buf, &tmp_pathname);
- if (tmp_fd >= 0)
- tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
-
+ TRY_CATCH (ex, RETURN_MASK_ALL)
+ {
+ tmp_bfd = solib_bfd_open (buf);
+ }
if (tmp_bfd == NULL)
goto bkpt_at_symbol;
- /* Make sure the dynamic linker's really a useful object. */
- if (!bfd_check_format (tmp_bfd, bfd_object))
- {
- warning (_("Unable to grok dynamic linker %s as an object file"), buf);
- bfd_close (tmp_bfd);
- goto bkpt_at_symbol;
- }
-
/* Now convert the TMP_BFD into a target. That way target, as
well as BFD operations can be used. Note that closing the
target will also close the underlying bfd. */
@@ -1166,7 +1158,6 @@ enable_break (void)
/* For whatever reason we couldn't set a breakpoint in the dynamic
linker. Warn and drop into the old code. */
bkpt_at_symbol:
- xfree (tmp_pathname);
warning (_("Unable to find dynamic linker breakpoint function.\n"
"GDB will be unable to debug shared library initializers\n"
"and track explicitly loaded dynamic code."));
diff -urNp gdb-orig/gdb/solist.h gdb-head/gdb/solist.h
--- gdb-orig/gdb/solist.h 2008-08-14 17:55:46.791410442 +0200
+++ gdb-head/gdb/solist.h 2008-08-14 22:09:06.626803770 +0200
@@ -127,7 +127,7 @@ void free_so (struct so_list *so);
struct so_list *master_so_list (void);
/* Find solib binary file and open it. */
-extern int solib_open (char *in_pathname, char **found_pathname);
+extern bfd *solib_bfd_open (char *in_pathname);
/* FIXME: gdbarch needs to control this variable */
extern struct target_so_ops *current_target_so_ops;
diff -urNp gdb-orig/gdb/symfile.c gdb-head/gdb/symfile.c
--- gdb-orig/gdb/symfile.c 2008-08-14 17:55:46.827405285 +0200
+++ gdb-head/gdb/symfile.c 2008-08-14 22:09:06.652800043 +0200
@@ -53,6 +53,7 @@
#include "varobj.h"
#include "elf-bfd.h"
#include "solib.h"
+#include "remote.h"
#include <sys/types.h>
#include <fcntl.h>
@@ -1266,7 +1267,10 @@ build_id_verify (const char *filename, s
int retval = 0;
/* We expect to be silent on the non-existing files. */
- abfd = bfd_openr (filename, gnutarget);
+ if (remote_filename_p (filename))
+ abfd = remote_bfd_open (filename, gnutarget);
+ else
+ abfd = bfd_openr (filename, gnutarget);
if (abfd == NULL)
return 0;
@@ -1357,18 +1361,22 @@ static int
separate_debug_file_exists (const char *name, unsigned long crc)
{
unsigned long file_crc = 0;
- int fd;
+ bfd *abfd;
gdb_byte buffer[8*1024];
int count;
- fd = open (name, O_RDONLY | O_BINARY);
- if (fd < 0)
+ if (remote_filename_p (name))
+ abfd = remote_bfd_open (name, gnutarget);
+ else
+ abfd = bfd_openr (name, gnutarget);
+
+ if (!abfd)
return 0;
- while ((count = read (fd, buffer, sizeof (buffer))) > 0)
+ while ((count = bfd_bread (buffer, sizeof (buffer), abfd)) > 0)
file_crc = gnu_debuglink_crc32 (file_crc, buffer, count);
- close (fd);
+ bfd_close (abfd);
return crc == file_crc;
}
@@ -1614,6 +1622,28 @@ symfile_bfd_open (char *name)
int desc;
char *absolute_name;
+ if (remote_filename_p (name))
+ {
+ name = xstrdup (name);
+ sym_bfd = remote_bfd_open (name, gnutarget);
+ if (!sym_bfd)
+ {
+ make_cleanup (xfree, name);
+ error (_("`%s': can't open to read symbols: %s."), name,
+ bfd_errmsg (bfd_get_error ()));
+ }
+
+ if (!bfd_check_format (sym_bfd, bfd_object))
+ {
+ bfd_close (sym_bfd);
+ make_cleanup (xfree, name);
+ error (_("`%s': can't read symbols: %s."), name,
+ bfd_errmsg (bfd_get_error ()));
+ }
+
+ return sym_bfd;
+ }
+
name = tilde_expand (name); /* Returns 1st new malloc'd copy. */
/* Look down path for it, allocate 2nd new malloc'd copy. */
@@ -1644,7 +1674,7 @@ symfile_bfd_open (char *name)
{
close (desc);
make_cleanup (xfree, name);
- error (_("\"%s\": can't open to read symbols: %s."), name,
+ error (_("`%s': can't open to read symbols: %s."), name,
bfd_errmsg (bfd_get_error ()));
}
bfd_set_cacheable (sym_bfd, 1);
@@ -1656,7 +1686,7 @@ symfile_bfd_open (char *name)
with the bfd). */
bfd_close (sym_bfd); /* This also closes desc. */
make_cleanup (xfree, name);
- error (_("\"%s\": can't read symbols: %s."), name,
+ error (_("`%s': can't read symbols: %s."), name,
bfd_errmsg (bfd_get_error ()));
}
@@ -2357,7 +2387,10 @@ reread_symbols (void)
if (!bfd_close (objfile->obfd))
error (_("Can't close BFD for %s: %s"), objfile->name,
bfd_errmsg (bfd_get_error ()));
- objfile->obfd = bfd_openr (obfd_filename, gnutarget);
+ if (remote_filename_p (obfd_filename))
+ objfile->obfd = remote_bfd_open (obfd_filename, gnutarget);
+ else
+ objfile->obfd = bfd_openr (obfd_filename, gnutarget);
if (objfile->obfd == NULL)
error (_("Can't open %s to read symbols."), objfile->name);
/* bfd_openr sets cacheable to true, which is what we want. */
--
Dr. Ulrich Weigand
GNU Toolchain for Linux on System z and Cell BE
Ulrich.Weigand@de.ibm.com