* [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
@ 2004-01-18 20:40 Mark Kettenis
2004-01-18 22:52 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Mark Kettenis @ 2004-01-18 20:40 UTC (permalink / raw)
To: gdb-patches
While adding support for OpenBSD ELF, I found myself duplicating the
same bit of code for checking ELF notes again. This patch puts that
bit of code in its own function. The new function adds a check
whether the nore section is large enough to contain the note that
we're checked for.
If nobody objects, I'll commit this in a few days,
Mark
Index: ChangeLog
from Mark Kettenis <kettenis@gnu.org>
* osabi.c (MAX_NOTESZ): New define.
(check_note): New function.
(generic_elf_osabi_sniff_abi_tag_sections): Reorganize code using
check_note.
Index: osabi.c
===================================================================
RCS file: /cvs/src/src/gdb/osabi.c,v
retrieving revision 1.25
diff -u -p -r1.25 osabi.c
--- osabi.c 17 Jan 2004 00:13:46 -0000 1.25
+++ osabi.c 18 Jan 2004 20:39:29 -0000
@@ -355,119 +355,126 @@ gdbarch_init_osabi (struct gdbarch_info
info.bfd_arch_info->printable_name);
}
\f
+/* Limit on the amount of data to be read. */
+#define MAX_NOTESZ 128
+
+/* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
+
+static int
+check_note (bfd *abfd, asection *sect, const char *note,
+ const char *name, unsigned long descsz, unsigned long type)
+{
+ unsigned long notesz;
+
+ /* Calculate the size of this note... */
+ notesz = strlen (name) + 1;
+ notesz = ((notesz + 3) & ~3);
+ notesz += descsz;
+ notesz = ((notesz + 3) & ~3);
+
+ /* ...and check it. */
+ gdb_assert (notesz <= MAX_NOTESZ);
+ if (notesz > bfd_section_size (abfd, sect))
+ return 0;
+
+ /* Check the note name. */
+ if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
+ || strcmp (note + 12, name) != 0)
+ return 0;
+
+ /* Check the descriptor size. */
+ if (bfd_h_get_32 (abfd, note + 4) != descsz)
+ return 0;
+
+ /* Check the note type. */
+ if (bfd_h_get_32 (abfd, note + 8) != type)
+ return 0;
+
+ return 1;
+}
/* Generic sniffer for ELF flavoured files. */
void
generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
{
- enum gdb_osabi *os_ident_ptr = obj;
+ enum gdb_osabi *osabi = obj;
const char *name;
unsigned int sectsize;
+ char *note;
name = bfd_get_section_name (abfd, sect);
sectsize = bfd_section_size (abfd, sect);
- /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
- if (strcmp (name, ".note.ABI-tag") == 0 && sectsize > 0)
- {
- unsigned int name_length, data_length, note_type;
- char *note;
+ /* Limit the amount of data to read. */
+ if (sectsize > MAX_NOTESZ)
+ sectsize = MAX_NOTESZ;
- /* If the section is larger than this, it's probably not what we are
- looking for. */
- if (sectsize > 128)
- sectsize = 128;
+ note = alloca (sectsize);
+ bfd_get_section_contents (abfd, sect, note, 0, sectsize);
- note = alloca (sectsize);
-
- bfd_get_section_contents (abfd, sect, note,
- (file_ptr) 0, (bfd_size_type) sectsize);
-
- name_length = bfd_h_get_32 (abfd, note);
- data_length = bfd_h_get_32 (abfd, note + 4);
- note_type = bfd_h_get_32 (abfd, note + 8);
-
- if (name_length == 4 && data_length == 16 && note_type == NT_GNU_ABI_TAG
- && strcmp (note + 12, "GNU") == 0)
+ /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
+ if (strcmp (name, ".note.ABI-tag") == 0)
+ {
+ /* GNU. */
+ if (check_note (abfd, sect, note, "GNU", 16, NT_GNU_ABI_TAG))
{
- int os_number = bfd_h_get_32 (abfd, note + 16);
+ unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
- switch (os_number)
+ switch (abi_tag)
{
case GNU_ABI_TAG_LINUX:
- *os_ident_ptr = GDB_OSABI_LINUX;
+ *osabi = GDB_OSABI_LINUX;
break;
case GNU_ABI_TAG_HURD:
- *os_ident_ptr = GDB_OSABI_HURD;
+ *osabi = GDB_OSABI_HURD;
break;
case GNU_ABI_TAG_SOLARIS:
- *os_ident_ptr = GDB_OSABI_SOLARIS;
+ *osabi = GDB_OSABI_SOLARIS;
break;
case GNU_ABI_TAG_FREEBSD:
- *os_ident_ptr = GDB_OSABI_FREEBSD_ELF;
+ *osabi = GDB_OSABI_FREEBSD_ELF;
break;
-
+
case GNU_ABI_TAG_NETBSD:
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
+ *osabi = GDB_OSABI_NETBSD_ELF;
break;
-
+
default:
- internal_error
- (__FILE__, __LINE__,
- "generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
- os_number);
+ internal_error (__FILE__, __LINE__, "\
+generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
+ abi_tag);
}
return;
}
- else if (name_length == 8 && data_length == 4
- && note_type == NT_FREEBSD_ABI_TAG
- && strcmp (note + 12, "FreeBSD") == 0)
+
+ /* FreeBSD. */
+ if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_ABI_TAG))
{
- /* XXX Should we check the version here? Probably not
- necessary yet. */
- *os_ident_ptr = GDB_OSABI_FREEBSD_ELF;
+ /* There is no need to check the version yet. */
+ *osabi = GDB_OSABI_FREEBSD_ELF;
+ return;
}
+
return;
}
-
+
/* .note.netbsd.ident notes, used by NetBSD. */
- if (strcmp (name, ".note.netbsd.ident") == 0 && sectsize > 0)
+ if (strcmp (name, ".note.netbsd.ident") == 0
+ && check_note (abfd, sect, note, "NetBSD", 4, NT_NETBSD_IDENT))
{
- unsigned int name_length, data_length, note_type;
- char *note;
-
- /* If the section is larger than this, it's probably not what we are
- looking for. */
- if (sectsize > 128)
- sectsize = 128;
-
- note = alloca (sectsize);
-
- bfd_get_section_contents (abfd, sect, note,
- (file_ptr) 0, (bfd_size_type) sectsize);
-
- name_length = bfd_h_get_32 (abfd, note);
- data_length = bfd_h_get_32 (abfd, note + 4);
- note_type = bfd_h_get_32 (abfd, note + 8);
-
- if (name_length == 7 && data_length == 4 && note_type == NT_NETBSD_IDENT
- && strcmp (note + 12, "NetBSD") == 0)
- {
- /* XXX Should we check the version here? Probably not
- necessary yet. */
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
- }
+ /* There is no need to check the version yet. */
+ *osabi = GDB_OSABI_NETBSD_ELF;
return;
}
/* .note.netbsdcore.procinfo notes, used by NetBSD. */
- if (strcmp (name, ".note.netbsdcore.procinfo") == 0 && sectsize > 0)
+ if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
{
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
+ *osabi = GDB_OSABI_NETBSD_ELF;
return;
}
}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
2004-01-18 20:40 [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections() Mark Kettenis
@ 2004-01-18 22:52 ` Daniel Jacobowitz
2004-01-19 18:39 ` Mark Kettenis
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2004-01-18 22:52 UTC (permalink / raw)
To: gdb-patches
On Sun, Jan 18, 2004 at 09:40:40PM +0100, Mark Kettenis wrote:
> + /* ...and check it. */
> + gdb_assert (notesz <= MAX_NOTESZ);
> + if (notesz > bfd_section_size (abfd, sect))
> + return 0;
I'd rather not add assertions based on the input file. Can we complain
and fail instead?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
2004-01-18 22:52 ` Daniel Jacobowitz
@ 2004-01-19 18:39 ` Mark Kettenis
2004-01-19 19:15 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Mark Kettenis @ 2004-01-19 18:39 UTC (permalink / raw)
To: drow; +Cc: gdb-patches
Date: Sun, 18 Jan 2004 17:52:54 -0500
From: Daniel Jacobowitz <drow@mvista.com>
On Sun, Jan 18, 2004 at 09:40:40PM +0100, Mark Kettenis wrote:
> + /* ...and check it. */
> + gdb_assert (notesz <= MAX_NOTESZ);
> + if (notesz > bfd_section_size (abfd, sect))
> + return 0;
I'd rather not add assertions based on the input file. Can we complain
and fail instead?
Ah, but the assert is an internal consistency check. It checks
whether the MAX_NOTESZ limit is large enough for the note the caller
of check_note() is checking for. Basically the assert triggers if
someone adds a check_note() call with a long name, or a large
descriptor size. In that case the person in question should increase
MAX_NOTESZ. The assert is guaranteed not to be triggered for the
check_note() calls in my patch.
The following if-statement does a sanity check on the input file. We
simply return 0 is the section is too small.
I'll add some comments spelling this out before I check this in.
Mark
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
2004-01-19 18:39 ` Mark Kettenis
@ 2004-01-19 19:15 ` Daniel Jacobowitz
2004-01-21 23:08 ` Mark Kettenis
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2004-01-19 19:15 UTC (permalink / raw)
To: gdb-patches
On Mon, Jan 19, 2004 at 07:39:03PM +0100, Mark Kettenis wrote:
> Date: Sun, 18 Jan 2004 17:52:54 -0500
> From: Daniel Jacobowitz <drow@mvista.com>
>
> On Sun, Jan 18, 2004 at 09:40:40PM +0100, Mark Kettenis wrote:
> > + /* ...and check it. */
> > + gdb_assert (notesz <= MAX_NOTESZ);
> > + if (notesz > bfd_section_size (abfd, sect))
> > + return 0;
>
> I'd rather not add assertions based on the input file. Can we complain
> and fail instead?
>
> Ah, but the assert is an internal consistency check. It checks
> whether the MAX_NOTESZ limit is large enough for the note the caller
> of check_note() is checking for. Basically the assert triggers if
> someone adds a check_note() call with a long name, or a large
> descriptor size. In that case the person in question should increase
> MAX_NOTESZ. The assert is guaranteed not to be triggered for the
> check_note() calls in my patch.
Oh, you're right - I leapt to the conclusion that this was based on the
size of notes in the input. Sorry.
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
2004-01-19 19:15 ` Daniel Jacobowitz
@ 2004-01-21 23:08 ` Mark Kettenis
2004-01-22 7:35 ` Eli Zaretskii
0 siblings, 1 reply; 6+ messages in thread
From: Mark Kettenis @ 2004-01-21 23:08 UTC (permalink / raw)
To: gdb-patches
Daniel's confusement (can I say that in english?) caused me to tweak
some comments. The attached is what I committed.
Mark
Index: ChangeLog
from Mark Kettenis <kettenis@gnu.org>
* osabi.c (MAX_NOTESZ): New define.
(check_note): New function.
(generic_elf_osabi_sniff_abi_tag_sections): Reorganize code using
check_note.
Index: osabi.c
===================================================================
RCS file: /cvs/src/src/gdb/osabi.c,v
retrieving revision 1.25
diff -u -p -r1.25 osabi.c
--- osabi.c 17 Jan 2004 00:13:46 -0000 1.25
+++ osabi.c 21 Jan 2004 23:02:22 -0000
@@ -355,119 +355,128 @@ gdbarch_init_osabi (struct gdbarch_info
info.bfd_arch_info->printable_name);
}
\f
+/* Limit on the amount of data to be read. */
+#define MAX_NOTESZ 128
+
+/* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. */
+
+static int
+check_note (bfd *abfd, asection *sect, const char *note,
+ const char *name, unsigned long descsz, unsigned long type)
+{
+ unsigned long notesz;
+
+ /* Calculate the size of this note. */
+ notesz = strlen (name) + 1;
+ notesz = ((notesz + 3) & ~3);
+ notesz += descsz;
+ notesz = ((notesz + 3) & ~3);
+
+ /* If this assertion triggers, increase MAX_NOTESZ. */
+ gdb_assert (notesz <= MAX_NOTESZ);
+
+ /* Check whether SECT is big enough to comtain the complete note. */
+ if (notesz > bfd_section_size (abfd, sect))
+ return 0;
+
+ /* Check the note name. */
+ if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
+ || strcmp (note + 12, name) != 0)
+ return 0;
+
+ /* Check the descriptor size. */
+ if (bfd_h_get_32 (abfd, note + 4) != descsz)
+ return 0;
+
+ /* Check the note type. */
+ if (bfd_h_get_32 (abfd, note + 8) != type)
+ return 0;
+
+ return 1;
+}
/* Generic sniffer for ELF flavoured files. */
void
generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
{
- enum gdb_osabi *os_ident_ptr = obj;
+ enum gdb_osabi *osabi = obj;
const char *name;
unsigned int sectsize;
+ char *note;
name = bfd_get_section_name (abfd, sect);
sectsize = bfd_section_size (abfd, sect);
- /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
- if (strcmp (name, ".note.ABI-tag") == 0 && sectsize > 0)
- {
- unsigned int name_length, data_length, note_type;
- char *note;
+ /* Limit the amount of data to read. */
+ if (sectsize > MAX_NOTESZ)
+ sectsize = MAX_NOTESZ;
- /* If the section is larger than this, it's probably not what we are
- looking for. */
- if (sectsize > 128)
- sectsize = 128;
+ note = alloca (sectsize);
+ bfd_get_section_contents (abfd, sect, note, 0, sectsize);
- note = alloca (sectsize);
-
- bfd_get_section_contents (abfd, sect, note,
- (file_ptr) 0, (bfd_size_type) sectsize);
-
- name_length = bfd_h_get_32 (abfd, note);
- data_length = bfd_h_get_32 (abfd, note + 4);
- note_type = bfd_h_get_32 (abfd, note + 8);
-
- if (name_length == 4 && data_length == 16 && note_type == NT_GNU_ABI_TAG
- && strcmp (note + 12, "GNU") == 0)
+ /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
+ if (strcmp (name, ".note.ABI-tag") == 0)
+ {
+ /* GNU. */
+ if (check_note (abfd, sect, note, "GNU", 16, NT_GNU_ABI_TAG))
{
- int os_number = bfd_h_get_32 (abfd, note + 16);
+ unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
- switch (os_number)
+ switch (abi_tag)
{
case GNU_ABI_TAG_LINUX:
- *os_ident_ptr = GDB_OSABI_LINUX;
+ *osabi = GDB_OSABI_LINUX;
break;
case GNU_ABI_TAG_HURD:
- *os_ident_ptr = GDB_OSABI_HURD;
+ *osabi = GDB_OSABI_HURD;
break;
case GNU_ABI_TAG_SOLARIS:
- *os_ident_ptr = GDB_OSABI_SOLARIS;
+ *osabi = GDB_OSABI_SOLARIS;
break;
case GNU_ABI_TAG_FREEBSD:
- *os_ident_ptr = GDB_OSABI_FREEBSD_ELF;
+ *osabi = GDB_OSABI_FREEBSD_ELF;
break;
-
+
case GNU_ABI_TAG_NETBSD:
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
+ *osabi = GDB_OSABI_NETBSD_ELF;
break;
-
+
default:
- internal_error
- (__FILE__, __LINE__,
- "generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
- os_number);
+ internal_error (__FILE__, __LINE__, "\
+generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
+ abi_tag);
}
return;
}
- else if (name_length == 8 && data_length == 4
- && note_type == NT_FREEBSD_ABI_TAG
- && strcmp (note + 12, "FreeBSD") == 0)
+
+ /* FreeBSD. */
+ if (check_note (abfd, sect, note, "FreeBSD", 4, NT_FREEBSD_ABI_TAG))
{
- /* XXX Should we check the version here? Probably not
- necessary yet. */
- *os_ident_ptr = GDB_OSABI_FREEBSD_ELF;
+ /* There is no need to check the version yet. */
+ *osabi = GDB_OSABI_FREEBSD_ELF;
+ return;
}
+
return;
}
-
+
/* .note.netbsd.ident notes, used by NetBSD. */
- if (strcmp (name, ".note.netbsd.ident") == 0 && sectsize > 0)
+ if (strcmp (name, ".note.netbsd.ident") == 0
+ && check_note (abfd, sect, note, "NetBSD", 4, NT_NETBSD_IDENT))
{
- unsigned int name_length, data_length, note_type;
- char *note;
-
- /* If the section is larger than this, it's probably not what we are
- looking for. */
- if (sectsize > 128)
- sectsize = 128;
-
- note = alloca (sectsize);
-
- bfd_get_section_contents (abfd, sect, note,
- (file_ptr) 0, (bfd_size_type) sectsize);
-
- name_length = bfd_h_get_32 (abfd, note);
- data_length = bfd_h_get_32 (abfd, note + 4);
- note_type = bfd_h_get_32 (abfd, note + 8);
-
- if (name_length == 7 && data_length == 4 && note_type == NT_NETBSD_IDENT
- && strcmp (note + 12, "NetBSD") == 0)
- {
- /* XXX Should we check the version here? Probably not
- necessary yet. */
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
- }
+ /* There is no need to check the version yet. */
+ *osabi = GDB_OSABI_NETBSD_ELF;
return;
}
/* .note.netbsdcore.procinfo notes, used by NetBSD. */
- if (strcmp (name, ".note.netbsdcore.procinfo") == 0 && sectsize > 0)
+ if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
{
- *os_ident_ptr = GDB_OSABI_NETBSD_ELF;
+ *osabi = GDB_OSABI_NETBSD_ELF;
return;
}
}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections()
2004-01-21 23:08 ` Mark Kettenis
@ 2004-01-22 7:35 ` Eli Zaretskii
0 siblings, 0 replies; 6+ messages in thread
From: Eli Zaretskii @ 2004-01-22 7:35 UTC (permalink / raw)
To: Mark Kettenis; +Cc: gdb-patches
> Date: Thu, 22 Jan 2004 00:08:09 +0100 (CET)
> From: Mark Kettenis <kettenis@chello.nl>
>
> Daniel's confusement (can I say that in english?)
I believe you meant to say ``confusion''.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2004-01-18 20:40 [PATCH/RFC] Reorganize osabi.c:generic_elf_osabi_sniff_abi_tag_sections() Mark Kettenis
2004-01-18 22:52 ` Daniel Jacobowitz
2004-01-19 18:39 ` Mark Kettenis
2004-01-19 19:15 ` Daniel Jacobowitz
2004-01-21 23:08 ` Mark Kettenis
2004-01-22 7:35 ` Eli Zaretskii
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