* [PATCH v2 2/4] Document new {set,show} dump-excluded-mappings commands.
2017-11-29 10:55 [PATCH v2 0/4] Enable the user to dump all memory regions Sergio Lopez
@ 2017-11-29 10:55 ` Sergio Lopez
2017-11-29 17:40 ` Eli Zaretskii
2017-11-29 10:56 ` [PATCH v2 1/4] Implement 'set dump-excluded-mappings' command Sergio Lopez
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: Sergio Lopez @ 2017-11-29 10:55 UTC (permalink / raw)
To: gdb-patches; +Cc: Sergio Lopez
gdb/ChangeLog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* NEWS (Changes since GDB 8.0): Announce {set,show}
dump_excluded_mappings commands.
gdb/doc/ChangeLog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* gdb.texinfo (gcore): Mention new {set,show}
dump-excluded-mappings commands.
(set dump-excluded-mappings): Document new command.
---
gdb/NEWS | 5 +++++
gdb/doc/gdb.texinfo | 14 +++++++++++++-
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index 754ce103bd..1372552a37 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -134,6 +134,11 @@ set debug separate-debug-file
show debug separate-debug-file
Control the display of debug output about separate debug file search.
+set dump-excluded-mappings
+show dump-excluded-mappings
+ Control whether mappings marked with the VM_DONTDUMP flag should be
+ dumped when generating a core file.
+
maint info selftests
List the registered selftests.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 675f6e7bc8..7b25912e49 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -11543,7 +11543,9 @@ this writing, @sc{gnu}/Linux, FreeBSD, Solaris, and S390).
On @sc{gnu}/Linux, this command can take into account the value of the
file @file{/proc/@var{pid}/coredump_filter} when generating the core
-dump (@pxref{set use-coredump-filter}).
+dump (@pxref{set use-coredump-filter}), and by default honors the
+@code{VM_DONTDUMP} flag for mappings where it is present in the file
+@file{/proc/@var{pid}/smaps} (@pxref{set dump-excluded-mappings}).
@kindex set use-coredump-filter
@anchor{set use-coredump-filter}
@@ -11573,6 +11575,16 @@ value is currently @code{0x33}, which means that bits @code{0}
(anonymous private mappings), @code{1} (anonymous shared mappings),
@code{4} (ELF headers) and @code{5} (private huge pages) are active.
This will cause these memory mappings to be dumped automatically.
+
+@kindex set dump-excluded-mappings
+@anchor{set dump-excluded-mappings}
+@item set dump-excluded-mappings on
+@itemx set dump-excluded-mappings off
+If @code{on} is specified, @value{GDBN} will dump memory mappings
+marked with the @code{VM_DONTDUMP} flag. This flag is represented in
+the file @file{/proc/@var{pid}/smaps} with the acronym @code{dd}.
+
+The default value is @code{off}.
@end table
@node Character Sets
--
2.14.3
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2 2/4] Document new {set,show} dump-excluded-mappings commands.
2017-11-29 10:55 ` [PATCH v2 2/4] Document new {set,show} dump-excluded-mappings commands Sergio Lopez
@ 2017-11-29 17:40 ` Eli Zaretskii
0 siblings, 0 replies; 7+ messages in thread
From: Eli Zaretskii @ 2017-11-29 17:40 UTC (permalink / raw)
To: Sergio Lopez; +Cc: gdb-patches
> From: Sergio Lopez <slp@redhat.com>
> Cc: Sergio Lopez <slp@redhat.com>
> Date: Wed, 29 Nov 2017 11:55:41 +0100
>
> gdb/ChangeLog:
> 2017-11-29 Sergio Lopez <slp@redhat.com>
>
> * NEWS (Changes since GDB 8.0): Announce {set,show}
> dump_excluded_mappings commands.
>
> gdb/doc/ChangeLog:
> 2017-11-29 Sergio Lopez <slp@redhat.com>
>
> * gdb.texinfo (gcore): Mention new {set,show}
> dump-excluded-mappings commands.
> (set dump-excluded-mappings): Document new command.
OK.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2 1/4] Implement 'set dump-excluded-mappings' command
2017-11-29 10:55 [PATCH v2 0/4] Enable the user to dump all memory regions Sergio Lopez
2017-11-29 10:55 ` [PATCH v2 2/4] Document new {set,show} dump-excluded-mappings commands Sergio Lopez
@ 2017-11-29 10:56 ` Sergio Lopez
2017-11-29 10:56 ` [PATCH v2 4/4] Document the new "-a" command line option for gcore Sergio Lopez
2017-11-29 10:56 ` [PATCH v2 3/4] Implement " Sergio Lopez
3 siblings, 0 replies; 7+ messages in thread
From: Sergio Lopez @ 2017-11-29 10:56 UTC (permalink / raw)
To: gdb-patches; +Cc: Sergio Lopez
Commit df8411da087dc05481926f4c4a82deabc5bc3859 implemented support for
checking /proc/PID/coredump_filter, and also changed gcore behavior to
unconditionally honor the VM_DONTDUMP flag, preventing sections marked
as such for being dumped into the core file.
This patch implements the 'set dump-excluded-mappings' command for
instructing gdb to ignore the VM_DONTDUMP flag. Combined with 'set
use-coredump-filter', this allows the user to restore the old behavior,
dumping all sections (except the ones marked as IO) unconditionally.
gdb/Changelog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* linux-tdep.c (dump_excluded_mappings): New variable.
(dump_mapping_p): Use dump_excluded_mappings variable.
(_initialize_linux_tdep): New command 'set dump_excluded_mappings'.
---
gdb/linux-tdep.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 24237b8d39..e458398137 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -93,6 +93,12 @@ struct smaps_vmflags
static int use_coredump_filter = 1;
+/* Whether the value of smaps_vmflags->exclude_coredump should be
+ ignored, including mappings marked with the VM_DONTDUMP flag in
+ the dump. */
+
+static int dump_excluded_mappings = 0;
+
/* This enum represents the signals' numbers on a generic architecture
running the Linux kernel. The definition of "generic" comes from
the file <include/uapi/asm-generic/signal.h>, from the Linux kernel
@@ -655,7 +661,7 @@ dump_mapping_p (filter_flags filterflags, const struct smaps_vmflags *v,
return 0;
/* Check if we should exclude this mapping. */
- if (v->exclude_coredump)
+ if (!dump_excluded_mappings && v->exclude_coredump)
return 0;
/* Update our notion of whether this mapping is shared or
@@ -2469,6 +2475,17 @@ show_use_coredump_filter (struct ui_file *file, int from_tty,
" corefiles is %s.\n"), value);
}
+/* Display whether the gcore command is dumping mappings marked with
+ the VM_DONTDUMP flag. */
+
+static void
+show_dump_excluded_mappings (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Dumping of mappings marked with the VM_DONTDUMP"
+ " flag is %s.\n"), value);
+}
+
/* To be called from the various GDB_OSABI_LINUX handlers for the
various GNU/Linux architectures and machine types. */
@@ -2517,4 +2534,16 @@ of /proc/PID/coredump_filter when generating the corefile. For more information
about this file, refer to the manpage of core(5)."),
NULL, show_use_coredump_filter,
&setlist, &showlist);
+
+ add_setshow_boolean_cmd ("dump-excluded-mappings", class_files,
+ &dump_excluded_mappings, _("\
+Set whether gcore should dump mappings marked with the VM_DONTDUMP flag."),
+ _("\
+Show whether gcore should dump mappings marked with the VM_DONTDUMP flag."),
+ _("\
+Use this command to set whether gcore should dump mappings marked with the\n\
+VM_DONTDUMP flag (\"dd\" in /proc/PID/smaps) when generating the corefile. For\n\
+more information about this file, refer to the manpage of proc(5) and core(5)."),
+ NULL, show_dump_excluded_mappings,
+ &setlist, &showlist);
}
--
2.14.3
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v2 4/4] Document the new "-a" command line option for gcore
2017-11-29 10:55 [PATCH v2 0/4] Enable the user to dump all memory regions Sergio Lopez
2017-11-29 10:55 ` [PATCH v2 2/4] Document new {set,show} dump-excluded-mappings commands Sergio Lopez
2017-11-29 10:56 ` [PATCH v2 1/4] Implement 'set dump-excluded-mappings' command Sergio Lopez
@ 2017-11-29 10:56 ` Sergio Lopez
2017-11-29 17:41 ` Eli Zaretskii
2017-11-29 10:56 ` [PATCH v2 3/4] Implement " Sergio Lopez
3 siblings, 1 reply; 7+ messages in thread
From: Sergio Lopez @ 2017-11-29 10:56 UTC (permalink / raw)
To: gdb-patches; +Cc: Sergio Lopez
gdb/ChangeLog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* NEWS (Changes since GDB 8.0): Announce new "-a"
command line option for gcore.
gdb/doc/ChangeLog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* gdb.texinfo (gcore man): Document new "-a" command line option.
---
gdb/NEWS | 5 +++++
gdb/doc/gdb.texinfo | 7 ++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index 1372552a37..ce84fe7924 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -52,6 +52,11 @@
** The "complete" command now mimics TAB completion accurately.
+* New command line options (gcore)
+
+-a
+ Dump all memory mappings.
+
* Python Scripting
** New events gdb.new_inferior, gdb.inferior_deleted, and
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 7b25912e49..88d6820998 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -42948,7 +42948,7 @@ Richard M. Stallman and Roland H. Pesch, July 1991.
@format
@c man begin SYNOPSIS gcore
-gcore [-o @var{filename}] @var{pid}
+gcore [-a] [-o @var{filename}] @var{pid}
@c man end
@end format
@@ -42962,6 +42962,11 @@ running without any change.
@c man begin OPTIONS gcore
@table @env
+@item -a
+Dump all memory mappings. The actual effect of this option depends on the
+Operating System. On @sc{gnu}/Linux, it will disable
+@code{use-coredump-filter} and enable @code{dump-excluded-mappings}.
+
@item -o @var{filename}
The optional argument
@var{filename} specifies the file name where to put the core dump.
--
2.14.3
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v2 3/4] Implement "-a" command line option for gcore
2017-11-29 10:55 [PATCH v2 0/4] Enable the user to dump all memory regions Sergio Lopez
` (2 preceding siblings ...)
2017-11-29 10:56 ` [PATCH v2 4/4] Document the new "-a" command line option for gcore Sergio Lopez
@ 2017-11-29 10:56 ` Sergio Lopez
3 siblings, 0 replies; 7+ messages in thread
From: Sergio Lopez @ 2017-11-29 10:56 UTC (permalink / raw)
To: gdb-patches; +Cc: Sergio Lopez
With the new "-a" command line option, the user may request gcore to
actually dump all present memory mappings. The actual effect of this
argument is OS dependent.
On GNU/Linux, it will disable use-coredump-filter and enable
dump-excluded-mappings.
gdb/ChangeLog:
2017-11-29 Sergio Lopez <slp@redhat.com>
* gcore.in: Add "-a" command line option for instructing gdb to
dump all memory mappings (OS dependent).
---
gdb/gcore.in | 47 ++++++++++++++++++++++++++++++-----------------
1 file changed, 30 insertions(+), 17 deletions(-)
diff --git a/gdb/gcore.in b/gdb/gcore.in
index 632f21bdfa..44b2e98b27 100644
--- a/gdb/gcore.in
+++ b/gdb/gcore.in
@@ -20,27 +20,39 @@
# It starts up gdb, attaches to the given PID and invokes the gcore command.
#
-if [ "$#" -eq "0" ]
-then
- echo "usage: @GCORE_TRANSFORM_NAME@ [-o filename] pid"
- exit 2
-fi
-
# Need to check for -o option, but set default basename to "core".
name=core
-if [ "$1" = "-o" ]
+# When the -a option is present, this may hold additional commands
+# to ensure gdb dumps all mappings (OS dependent).
+dump_all_cmds=()
+
+while getopts :ao: opt; do
+ case $opt in
+ a)
+ case $OSTYPE in
+ linux*)
+ dump_all_cmds=("-ex" "set use-coredump-filter off")
+ dump_all_cmds+=("-ex" "set dump-excluded-mappings on")
+ ;;
+ esac
+ ;;
+ o)
+ name=$OPTARG
+ ;;
+ *)
+ echo "usage: @GCORE_TRANSFORM_NAME@ [-a] [-o filename] pid"
+ exit 2
+ ;;
+ esac
+done
+
+shift $((OPTIND-1))
+
+if [ "$#" -eq "0" ]
then
- if [ "$#" -lt "3" ]
- then
- # Not enough arguments.
- echo "usage: @GCORE_TRANSFORM_NAME@ [-o filename] pid"
- exit 2
- fi
- name=$2
-
- # Shift over to start of pid list
- shift; shift
+ echo "usage: @GCORE_TRANSFORM_NAME@ [-a] [-o filename] pid"
+ exit 2
fi
# Attempt to fetch the absolute path to the gcore script that was
@@ -87,6 +99,7 @@ do
# available but not accessible as GDB would get stopped on SIGTTIN.
$binary_path/@GDB_TRANSFORM_NAME@ </dev/null --nx --batch \
-ex "set pagination off" -ex "set height 0" -ex "set width 0" \
+ "${dump_all_cmds[@]}" \
-ex "attach $pid" -ex "gcore $name.$pid" -ex detach -ex quit
if [ -r $name.$pid ] ; then
--
2.14.3
^ permalink raw reply [flat|nested] 7+ messages in thread