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Re: RFA: ia64 portion of libunwind patch
- From: "J. Johnston" <jjohnstn at redhat dot com>
- To: Andrew Cagney <ac131313 at redhat dot com>
- Cc: Daniel Jacobowitz <drow at mvista dot com>,Kevin Buettner <kevinb at redhat dot com>,Marcel Moolenaar <marcel at xcllnt dot net>, gdb-patches at sources dot redhat dot com
- Date: Tue, 04 Nov 2003 14:09:47 -0500
- Subject: Re: RFA: ia64 portion of libunwind patch
- Organization: Red Hat Inc.
- References: <3F986E31.8050201@redhat.com> <1031024175718.ZM3475@localhost.localdomain> <3F996D88.9060505@redhat.com> <1031024185625.ZM9827@localhost.localdomain> <3F9F0180.2010702@redhat.com> <20031029012833.GA11070@nevyn.them.org> <3FA043B2.6090401@redhat.com>
I have chosen the first option to implement the syscall. I have included a
patch here regarding this mechanism.
Ok to commit?
-- Jeff J.
2003-11-04 Jeff Johnston <jjohnstn@redhat.com>
* config/ia64/nm-linux.h (CHILD_TO_XFER_PARTIAL): New macro to set up the
ia64 linux native target to_xfer_partial method.
(ia64_linux_xfer_partial): New prototype.
* ia64-linux-nat.c (ia64_linux_xfer_partial): New function.
* inftarg.c (init_child_ops)[CHILD_TO_XFER_PARTIAL]: Set up xfer partial
method if one provided via macro.
* target.c (init_dummy_target): Initialize to_xfer_partial to default.
* target.h (target_object): Add new TARGET_OBJECT_UNWIND_TABLE enum.
Andrew Cagney wrote:
Nothing which involves a syscall is acceptable in a tdep file. That's
what the t means - target support.
("tdep" mysteriously means "architecture vector support". That "t"
really no longer makes sense :-()
Yes, architecture vector shouldn't be directly making syscalls. Instead
the architecture specific code should use the target vector to obtain
this system information. Here I think the best option is to add another
TARGET_OBJECT_xxxx variant and then use the target_read() method to pull
in the data.
As for the native target side, ia64-linux-nat should export something
like ia64_linux_child_read_partial that performs the syscall. The
tricky [er messy] part is wiring it into child_ops, I see there are lots
of choices :-(
- define a nm-*.c macro and have that enable the assignment (ex #define
NATIVE_TO_READ_PARTIAL ia64_linux_child?) (ref KILL_INFERIOR)
- have a callback set the to_read_partial method in child_ops
(exec_set_find_memory_regions)
- modify all the targets so that each implements the new method
- others?
Is this information available via /proc? In a core file?
Andrew
PS: Note this pending patch. Dependant on the timing you or I may need
to tweak the name.
http://sources.redhat.com/ml/gdb-patches/2003-10/msg00795.html
Index: config/ia64/nm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/ia64/nm-linux.h,v
retrieving revision 1.10
diff -u -r1.10 nm-linux.h
--- config/ia64/nm-linux.h 20 Jun 2003 13:57:29 -0000 1.10
+++ config/ia64/nm-linux.h 4 Nov 2003 16:53:37 -0000
@@ -69,4 +69,13 @@
extern int ia64_linux_remove_watchpoint (ptid_t ptid, CORE_ADDR addr,
int len);
+#include "target.h"
+
+#define CHILD_TO_XFER_PARTIAL ia64_linux_xfer_partial
+extern LONGEST ia64_linux_xfer_partial (struct target_ops *ops,
+ enum target_object object,
+ const char *annex, const void *writebuf,
+ void *readbuf,
+ ULONGEST offset, LONGEST len);
+
#endif /* #ifndef NM_LINUX_H */
Index: ia64-linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/ia64-linux-nat.c,v
retrieving revision 1.20
diff -u -r1.20 ia64-linux-nat.c
--- ia64-linux-nat.c 2 Oct 2003 20:28:29 -0000 1.20
+++ ia64-linux-nat.c 4 Nov 2003 16:53:37 -0000
@@ -34,6 +34,7 @@
#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif
+#include <sys/syscall.h>
#include <sys/user.h>
#include <asm/ptrace_offsets.h>
@@ -644,4 +645,48 @@
write_register_pid (IA64_PSR_REGNUM, psr, ptid);
return (CORE_ADDR) siginfo.si_addr;
+}
+
+LONGEST
+ia64_linux_xfer_partial (struct target_ops *ops,
+ enum target_object object,
+ const char *annex, const void *writebuf,
+ void *readbuf,
+ ULONGEST offset, LONGEST len)
+{
+ switch (object)
+ {
+ case TARGET_OBJECT_UNWIND_TABLE:
+ return syscall (__NR_getunwind, readbuf, len);
+ case TARGET_OBJECT_MEMORY:
+ if (ops->to_xfer_memory != NULL)
+ /* Fall back to the target's "to_xfer_memory" method. */
+ {
+ int xfered = -1;
+ errno = 0;
+ if (writebuf != NULL)
+ {
+ void *buffer = xmalloc (len);
+ struct cleanup *cleanup = make_cleanup (xfree, buffer);
+ memcpy (buffer, writebuf, len);
+ xfered = ops->to_xfer_memory (offset, buffer, len, 1/*write*/, NULL,
+ ops);
+ do_cleanups (cleanup);
+ }
+ if (readbuf != NULL)
+ xfered = ops->to_xfer_memory (offset, readbuf, len, 0/*read*/, NULL,
+ ops);
+
+ if (xfered > 0)
+ return xfered;
+ else if (xfered == 0 && errno == 0)
+ /* "to_xfer_memory" uses 0, cross checked against ERRNO as one
+ indication of an error. */
+ return 0;
+ else
+ return -1;
+ }
+ default:
+ return -1;
+ }
}
Index: inftarg.c
===================================================================
RCS file: /cvs/src/src/gdb/inftarg.c,v
retrieving revision 1.18
diff -u -r1.18 inftarg.c
--- inftarg.c 21 Sep 2003 01:26:45 -0000 1.18
+++ inftarg.c 4 Nov 2003 16:53:37 -0000
@@ -609,6 +609,9 @@
child_ops.to_get_current_exception_event = child_get_current_exception_event;
child_ops.to_pid_to_exec_file = child_pid_to_exec_file;
child_ops.to_stratum = process_stratum;
+#ifdef CHILD_TO_XFER_PARTIAL
+ child_ops.to_xfer_partial = CHILD_TO_XFER_PARTIAL;
+#endif
child_ops.to_has_all_memory = 1;
child_ops.to_has_memory = 1;
child_ops.to_has_stack = 1;
Index: target.c
===================================================================
RCS file: /cvs/src/src/gdb/target.c,v
retrieving revision 1.64
diff -u -r1.64 target.c
--- target.c 31 Oct 2003 15:25:34 -0000 1.64
+++ target.c 4 Nov 2003 16:53:38 -0000
@@ -1644,6 +1644,7 @@
dummy_target.to_stratum = dummy_stratum;
dummy_target.to_find_memory_regions = dummy_find_memory_regions;
dummy_target.to_make_corefile_notes = dummy_make_corefile_notes;
+ dummy_target.to_xfer_partial = default_xfer_partial;
dummy_target.to_magic = OPS_MAGIC;
}
Index: target.h
===================================================================
RCS file: /cvs/src/src/gdb/target.h,v
retrieving revision 1.51
diff -u -r1.51 target.h
--- target.h 31 Oct 2003 19:19:51 -0000 1.51
+++ target.h 4 Nov 2003 16:53:38 -0000
@@ -223,8 +223,10 @@
/* AVR target specific transfer. See "avr-tdep.c" and "remote.c". */
TARGET_OBJECT_AVR,
/* Transfer up-to LEN bytes of memory starting at OFFSET. */
- TARGET_OBJECT_MEMORY
- /* Possible future ojbects: TARGET_OJBECT_FILE, TARGET_OBJECT_PROC,
+ TARGET_OBJECT_MEMORY,
+ /* Kernel Unwind Table. See "ia64-tdep.c". */
+ TARGET_OBJECT_UNWIND_TABLE,
+ /* Possible future objects: TARGET_OBJECT_FILE, TARGET_OBJECT_PROC,
TARGET_OBJECT_AUXV, ... */
};