On Sat, 2013-11-23 at 21:57 +0100, Jan Kratochvil wrote:
Besides changes described below I had to make some small libdwfl/
extension to
keep "Unwinding not supported for this architecture" error from
__libdwfl_attach_state_for_core() call in dwfl_core_file_report()
till the unwinding request later. One can for example comment out from
backends/i386_init.c
eh->frame_nregs = 9;
HOOK (eh, set_initial_registers_tid);
to test such behavior.
__libdwfl_attach_state_for_core() should not report error even if
dwfl_core_file_report() fails, as the caller may not want to unwind the core
at all. Still the error has to be kept somewhere.
That seems sensible. We use something similar for the Dwfl_Module when
the main or debug file cannot be loaded.
libdwfl/
2013-11-22 Jan Kratochvil <jan.kratochvil(a)redhat.com>
* dwfl_frame.c (dwfl_pid, dwfl_getthreads): Use PROCESS_ATTACH_ERROR if
PROCESS is NULL.
* libdwflP.h (struct Dwfl): New field process_attach_error.
* linux-core-attach.c (__libdwfl_attach_state_for_core): Rename to ...
(attach_state_for_core): ... here, make it static, change return type,
no longer use __libdwfl_seterrno.
(__libdwfl_attach_state_for_core): New wrapper for it.
This seems independent of the rest and almost correct (see one question
below). Lets get this in (short patches/commits are good IMHO).
diff --git a/libdwfl/dwfl_frame.c b/libdwfl/dwfl_frame.c
index f286350..4a7b3cd 100644
--- a/libdwfl/dwfl_frame.c
+++ b/libdwfl/dwfl_frame.c
@@ -200,7 +200,7 @@ dwfl_pid (Dwfl *dwfl)
{
if (dwfl->process == NULL)
{
- __libdwfl_seterrno (DWFL_E_NO_ATTACH_STATE);
+ __libdwfl_seterrno (dwfl->process_attach_error);
return -1;
}
return dwfl->process->pid;
@@ -235,7 +235,7 @@ dwfl_getthreads (Dwfl *dwfl, int (*callback) (Dwfl_Thread *thread,
void *arg),
Dwfl_Process *process = dwfl->process;
if (process == NULL)
{
- __libdwfl_seterrno (DWFL_E_NO_ATTACH_STATE);
+ __libdwfl_seterrno (dwfl->process_attach_error);
return -1;
}
Won't this return -1 and set the error to DWFL_E_NO_ERROR (0) in case no
attach has ever been attempted?
Maybe check that dwfl->process_attach_error != DWFL_E_NO_ERROR first.
And if it is then seterrno to DWFL_E_NO_ATTACH_STATE.
Or initialize dwfl->process_attach_error to DWFL_E_NO_ATTACH_STATE in
dwfl_begin?
diff --git a/libdwfl/libdwflP.h b/libdwfl/libdwflP.h
index b8a64d8..7e73e9e 100644
--- a/libdwfl/libdwflP.h
+++ b/libdwfl/libdwflP.h
@@ -108,6 +108,7 @@ struct Dwfl
Dwfl_Module *modulelist; /* List in order used by full traversals. */
Dwfl_Process *process;
+ Dwfl_Error process_attach_error;
GElf_Addr offline_next_address;
OK.
diff --git a/libdwfl/linux-core-attach.c
b/libdwfl/linux-core-attach.c
index 971d495..b2d703f 100644
--- a/libdwfl/linux-core-attach.c
+++ b/libdwfl/linux-core-attach.c
@@ -264,37 +264,30 @@ static const Dwfl_Thread_Callbacks core_thread_callbacks =
NULL, /* core_thread_detach */
};
-bool
-internal_function
-__libdwfl_attach_state_for_core (Dwfl *dwfl, Elf *core)
+static Dwfl_Error
+attach_state_for_core (Dwfl *dwfl, Elf *core)
{
Ebl *ebl = ebl_openbackend (core);
if (ebl == NULL)
- {
- __libdwfl_seterrno (DWFL_E_LIBEBL);
- return false;
- }
+ return DWFL_E_LIBEBL;
size_t nregs = ebl_frame_nregs (ebl);
if (nregs == 0)
{
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_LIBEBL);
- return false;
+ return DWFL_E_NO_UNWIND;
}
GElf_Ehdr ehdr_mem, *ehdr = gelf_getehdr (core, &ehdr_mem);
if (ehdr == NULL)
{
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_LIBELF);
- return false;
+ return DWFL_E_LIBELF;
}
assert (ehdr->e_type == ET_CORE);
size_t phnum;
if (elf_getphdrnum (core, &phnum) < 0)
{
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_LIBELF);
- return false;
+ return DWFL_E_LIBELF;
}
pid_t pid = -1;
Elf_Data *note_data = NULL;
@@ -311,8 +304,7 @@ __libdwfl_attach_state_for_core (Dwfl *dwfl, Elf *core)
if (note_data == NULL)
{
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_LIBELF);
- return NULL;
+ return DWFL_E_LIBELF;
}
size_t offset = 0;
GElf_Nhdr nhdr;
@@ -355,15 +347,13 @@ __libdwfl_attach_state_for_core (Dwfl *dwfl, Elf *core)
{
/* No valid NT_PRPSINFO recognized in this CORE. */
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_BADELF);
- return false;
+ return DWFL_E_BADELF;
}
struct core_arg *core_arg = malloc (sizeof *core_arg);
if (core_arg == NULL)
{
ebl_closebackend (ebl);
- __libdwfl_seterrno (DWFL_E_NOMEM);
- return false;
+ return DWFL_E_NOMEM;
}
OK.
@@ -372,8 +362,30 @@ __libdwfl_attach_state_for_core (Dwfl *dwfl, Elf
*core)
if (! INTUSE(dwfl_attach_state) (dwfl, core, pid, &core_thread_callbacks,
core_arg))
{
+ Dwfl_Error error = dwfl_errno ();
+ assert (error != DWFL_E_NOERROR);
free (core_arg);
ebl_closebackend (ebl);
+ return error;
+ }
+ return DWFL_E_NOERROR;
+}
OK.
+bool
+internal_function
+__libdwfl_attach_state_for_core (Dwfl *dwfl, Elf *core)
+{
+ if (dwfl->process != NULL)
+ {
+ __libdwfl_seterrno (DWFL_E_ATTACH_STATE_CONFLICT);
+ return false;
+ }
+ Dwfl_Error error = attach_state_for_core (dwfl, core);
+ assert ((dwfl->process != NULL) == (error == DWFL_E_NOERROR));
+ if (error != DWFL_E_NOERROR)
+ {
+ dwfl->process_attach_error = error;
+ __libdwfl_seterrno (error);
return false;
}
return true;
And depending on how to resolve the question above about dwfl_pid and
dwfl_getthreads set dwfl->process_attach_error to DWFL_E_NOERROR?
Thanks,
Mark