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authorYao Qi <yao@codesourcery.com>2014-01-27 20:35:33 +0800
committerYao Qi <yao@codesourcery.com>2014-02-11 14:20:33 +0800
commit9b409511d07fe375284701af34909fb539029caf (patch)
tree963bd8ab614e83e16bac7caa81c3081f69c505ef /gdb/inf-ptrace.c
parenta8e6308380e7c76bff431ed8477b85b4fd3b3542 (diff)
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Return target_xfer_status in to_xfer_partial
This patch does the conversion of to_xfer_partial from LONGEST (*to_xfer_partial) (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len); to enum target_xfer_status (*to_xfer_partial) (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, ULONGEST *xfered_len); It changes to_xfer_partial return the transfer status and the transfered length by *XFERED_LEN. Generally, the return status has three stats, - TARGET_XFER_OK, - TARGET_XFER_EOF, - TARGET_XFER_E_XXXX, See the comments to them in 'enum target_xfer_status'. Note that Pedro suggested not name TARGET_XFER_DONE, as it is confusing, compared with "TARGET_XFER_OK". We finally name it TARGET_XFER_EOF. With this change, GDB core can handle unavailable data in a convenient way. The rationale behind this change was mentioned here https://sourceware.org/ml/gdb-patches/2013-10/msg00761.html Consider an object/value like this: 0 100 150 200 512 DDDDDDDDDDDxxxxxxxxxDDDDDD...DDIIIIIIIIIIII..III where D is valid data, and xxx is unavailable data, and I is beyond the end of the object (Invalid). Currently, if we start the xfer at 0, requesting, say 512 bytes, we'll first get back 100 bytes. The xfer machinery then retries fetching [100,512), and gets back TARGET_XFER_E_UNAVAILABLE. That's sufficient when you're either interested in either having the whole of the 512 bytes available, or erroring out. But, in this scenario, we're interested in the data at [150,512). The problem is that the last TARGET_XFER_E_UNAVAILABLE gives us no indication where to start the read next. We'd need something like: get me [0,512) >>> <<< here's [0,100), *xfered_len is 100, returns TARGET_XFER_OK get me [100,512) >>> (**1) <<< [100,150) is unavailable, *xfered_len is 50, return TARGET_XFER_E_UNAVAILABLE. get me [150,512) >>> <<< here's [150,200), *xfered_len is 50, return TARGET_XFER_OK. get me [200,512) >>> <<< no more data, return TARGET_XFER_EOF. This naturally implies pushing down the decision of whether to return TARGET_XFER_E_UNAVAILABLE or something else down to the target. (Which kinds of leads back to tfile itself reading from RO memory from file (though we could export a function in exec.c for that that tfile delegates to, instead of re-adding the old code). Beside this change, we also add a macro TARGET_XFER_STATUS_ERROR_P to check whether a status is an error or not, to stop using "status < 0". This patch also eliminates the comparison between status and 0. No target implementations to to_xfer_partial adapts this new interface. The interface still behaves as before. gdb: 2014-02-11 Yao Qi <yao@codesourcery.com> * target.h (enum target_xfer_error): Rename to ... (enum target_xfer_status): ... it. New. All users updated. (enum target_xfer_status) <TARGET_XFER_OK>, <TARGET_XFER_EOF>: New. (TARGET_XFER_STATUS_ERROR_P): New macro. (target_xfer_error_to_string): Remove declaration. (target_xfer_status_to_string): Declare. (target_xfer_partial_ftype): Adjust it. (struct target_ops) <to_xfer_partial>: Return target_xfer_status. Add argument xfered_len. Update comments. * target.c (target_xfer_error_to_string): Rename to ... (target_xfer_status_to_string): ... it. New. All callers updated. (target_read_live_memory): Likewise. Call target_xfer_partial instead of target_read. (memory_xfer_live_readonly_partial): Return target_xfer_status. Add argument xfered_len. (raw_memory_xfer_partial): Likewise. (memory_xfer_partial_1): Likewise. (memory_xfer_partial): Likewise. (target_xfer_partial): Likewise. Check *XFERED_LEN is set properly. Update debug message. (default_xfer_partial, current_xfer_partial): Likewise. (target_write_partial): Likewise. (target_read_partial): Likewise. All callers updated. (read_whatever_is_readable): Likewise. (target_write_with_progress): Likewise. (target_read_alloc_1): Likewise. * aix-thread.c (aix_thread_xfer_partial): Likewise. * auxv.c (procfs_xfer_auxv): Likewise. (ld_so_xfer_auxv, memory_xfer_auxv): Likewise. * bfd-target.c (target_bfd_xfer_partial): Likewise. * bsd-kvm.c (bsd_kvm_xfer_partial): Likewise. * bsd-uthread.c (bsd_uthread_xfer_partia): Likewise. * corefile.c (read_memory): Adjust. * corelow.c (core_xfer_partial): Likewise. * ctf.c (ctf_xfer_partial): Likewise. * darwin-nat.c (darwin_read_dyld_info): Likewise. All callers updated. (darwin_xfer_partial): Likewise. * exec.c (section_table_xfer_memory_partial): Likewise. All callers updated. (exec_xfer_partial): Likewise. * exec.h (section_table_xfer_memory_partial): Update declaration. * gnu-nat.c (gnu_xfer_memory): Likewise. Assert 'res' is not negative. (gnu_xfer_partial): Likewise. * ia64-hpux-nat.c (ia64_hpux_xfer_memory_no_bs): Likewise. (ia64_hpux_xfer_memory, ia64_hpux_xfer_uregs): Likewise. (ia64_hpux_xfer_solib_got): Likewise. * inf-ptrace.c (inf_ptrace_xfer_partial): Likewise. Change type of 'partial_len' to ULONGEST. * inf-ttrace.c (inf_ttrace_xfer_partial): Likewise. * linux-nat.c (linux_xfer_siginfo ): Likewise. (linux_nat_xfer_partial): Likewise. (linux_proc_xfer_partial, linux_xfer_partial): Likewise. (linux_proc_xfer_spu, linux_nat_xfer_osdata): Likewise. * monitor.c (monitor_xfer_memory): Likewise. (monitor_xfer_partial): Likewise. * procfs.c (procfs_xfer_partial): Likewise. * record-btrace.c (record_btrace_xfer_partial): Likewise. * record-full.c (record_full_xfer_partial): Likewise. (record_full_core_xfer_partial): Likewise. * remote-sim.c (gdbsim_xfer_memory): Likewise. (gdbsim_xfer_partial): Likewise. * remote.c (remote_write_bytes_aux): Likewise. All callers updated. (remote_write_bytes, remote_read_bytes): Likewise. All callers updated. (remote_flash_erase): Likewise. All callers updated. (remote_write_qxfer): Likewise. All callers updated. (remote_read_qxfer): Likewise. All callers updated. (remote_xfer_partial): Likewise. * rs6000-nat.c (rs6000_xfer_partial): Likewise. (rs6000_xfer_shared_libraries): Likewise. * sol-thread.c (sol_thread_xfer_partial): Likewise. (sol_thread_xfer_partial): Likewise. * sparc-nat.c (sparc_xfer_wcookie): Likewise. (sparc_xfer_partial): Likewise. * spu-linux-nat.c (spu_proc_xfer_spu): Likewise. All callers updated. (spu_xfer_partial): Likewise. * spu-multiarch.c (spu_xfer_partial): Likewise. * tracepoint.c (tfile_xfer_partial): Likewise. * windows-nat.c (windows_xfer_memory): Likewise. (windows_xfer_shared_libraries): Likewise. (windows_xfer_partial): Likewise. * valprint.c: Replace 'target_xfer_error' with 'target_xfer_status' in comments.
Diffstat (limited to 'gdb/inf-ptrace.c')
-rw-r--r--gdb/inf-ptrace.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index dc3746b..edcad5a 100644
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -459,11 +459,11 @@ inf_ptrace_wait (struct target_ops *ops,
inferior's OBJECT:ANNEX space and GDB's READBUF/WRITEBUF buffer.
Return the number of bytes actually transferred. */
-static LONGEST
+static enum target_xfer_status
inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf,
- ULONGEST offset, ULONGEST len)
+ ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
{
pid_t pid = ptid_get_pid (inferior_ptid);
@@ -490,13 +490,16 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
errno = 0;
if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
- /* Return the actual number of bytes read or written. */
- return piod.piod_len;
+ {
+ *xfered_len = piod.piod_len;
+ /* Return the actual number of bytes read or written. */
+ return TARGET_XFER_OK;
+ }
/* If the PT_IO request is somehow not supported, fallback on
using PT_WRITE_D/PT_READ_D. Otherwise we will return zero
to indicate failure. */
if (errno != EINVAL)
- return 0;
+ return TARGET_XFER_EOF;
}
#endif
{
@@ -506,7 +509,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
} buffer;
ULONGEST rounded_offset;
- LONGEST partial_len;
+ ULONGEST partial_len;
/* Round the start offset down to the next long word
boundary. */
@@ -552,7 +555,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
(PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset,
buffer.word);
if (errno)
- return 0;
+ return TARGET_XFER_EOF;
}
}
@@ -563,13 +566,14 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
(PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset,
0);
if (errno)
- return 0;
+ return TARGET_XFER_EOF;
/* Copy appropriate bytes out of the buffer. */
memcpy (readbuf, buffer.byte + (offset - rounded_offset),
partial_len);
}
- return partial_len;
+ *xfered_len = partial_len;
+ return TARGET_XFER_OK;
}
case TARGET_OBJECT_UNWIND_TABLE:
@@ -592,8 +596,11 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
errno = 0;
if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
- /* Return the actual number of bytes read or written. */
- return piod.piod_len;
+ {
+ *xfered_len = piod.piod_len;
+ /* Return the actual number of bytes read or written. */
+ return TARGET_XFER_OK;
+ }
}
#endif
return TARGET_XFER_E_IO;