linux-toradex.git/scripts/gdb/linux/symbols.py, branch v5.19-rc3

scripts/gdb: handle split debug for vmlinux

2021-11-09T18:02:52+00:00

This is related to two previous changes.  Commit dfe4529ee4d3
("scripts/gdb: find vmlinux where it was before") and commit da036ae14762
("scripts/gdb: handle split debug").

Although Chrome OS has been using the debug suffix for modules for a
while, it has just recently started using it for vmlinux as well.  That
means we've now got to improve the detection of "vmlinux" to also handle
that it might end with ".debug".

Link: https://lkml.kernel.org/r/20211028151120.v2.1.Ie6bd5a232f770acd8c9ffae487a02170bad3e963@changeid
Signed-off-by: Douglas Anderson 
Reviewed-by: Stephen Boyd 
Cc: Jan Kiszka 
Cc: Kieran Bingham 
Cc: Johannes Berg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

gdb: lx-symbols: store the abspath()

2021-05-07T07:26:32+00:00

If we store the relative path, the user might later cd to a different
directory, and that would break the automatic symbol resolving that
happens when a module is loaded into the target kernel.  Fix this by
storing the abspath() of each path given, just like we already do for the
cwd (os.getcwd() is absolute.)

Link: https://lkml.kernel.org/r/20201217091747.bf4332cf2b35.I10ebbdb7e9b80ab1a5cddebf53d073be8232d656@changeid
Signed-off-by: Johannes Berg 
Reviewed-by: Jan Kiszka 
Cc: Kieran Bingham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: fix lx-symbols 'gdb.error' while loading modules

2020-07-24T19:42:42+00:00

Commit ed66f991bb19 ("module: Refactor section attr into bin attribute")
removed the 'name' field from 'struct module_sect_attr' triggering the
following error when invoking lx-symbols:

  (gdb) lx-symbols
  loading vmlinux
  scanning for modules in linux/build
  loading @0xffffffffc014f000: linux/build/drivers/net/tun.ko
  Python Exception  There is no member named name.:
  Error occurred in Python: There is no member named name.

This patch fixes the issue taking the module name from the 'struct
attribute'.

Fixes: ed66f991bb19 ("module: Refactor section attr into bin attribute")
Signed-off-by: Stefano Garzarella 
Signed-off-by: Andrew Morton 
Reviewed-by: Jan Kiszka 
Reviewed-by: Kieran Bingham 
Link: http://lkml.kernel.org/r/20200722102239.313231-1-sgarzare@redhat.com
Signed-off-by: Linus Torvalds

scripts/gdb: fix debugging modules compiled with hot/cold partitioning

2019-11-06T16:47:50+00:00

gcc's -freorder-blocks-and-partition option makes it group frequently
and infrequently used code in .text.hot and .text.unlikely sections
respectively.  At least when building modules on s390, this option is
used by default.

gdb assumes that all code is located in .text section, and that .text
section is located at module load address.  With such modules this is no
longer the case: there is code in .text.hot and .text.unlikely, and
either of them might precede .text.

Fix by explicitly telling gdb the addresses of code sections.

It might be tempting to do this for all sections, not only the ones in
the white list.  Unfortunately, gdb appears to have an issue, when
telling it about e.g. loadable .note.gnu.build-id section causes it to
think that non-loadable .note.Linux section is loaded at address 0,
which in turn causes NULL pointers to be resolved to bogus symbols.  So
keep using the white list approach for the time being.

Link: http://lkml.kernel.org/r/20191028152734.13065-1-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich 
Reviewed-by: Jan Kiszka 
Cc: Kieran Bingham 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: fix debugging modules on s390

2019-10-19T10:32:33+00:00

Currently lx-symbols assumes that module text is always located at
module->core_layout->base, but s390 uses the following layout:

  +------+  <- module->core_layout->base
  | GOT  |
  +------+  <- module->core_layout->base + module->arch->plt_offset
  | PLT  |
  +------+  <- module->core_layout->base + module->arch->plt_offset +
  | TEXT |     module->arch->plt_size
  +------+

Therefore, when trying to debug modules on s390, all the symbol
addresses are skewed by plt_offset + plt_size.

Fix by adding plt_offset + plt_size to module_addr in
load_module_symbols().

Link: http://lkml.kernel.org/r/20191017085917.81791-1-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich 
Reviewed-by: Jan Kiszka 
Cc: Kieran Bingham 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: handle split debug

2019-09-26T00:51:40+00:00

Some systems (like Chrome OS) may use "split debug" for kernel modules.
That means that the debug symbols are in a different file than the main
elf file.  Let's handle that by also searching for debug symbols that end
in ".ko.debug".

This is a packaging topic.  You can take a normal elf file and split the
debug out of it using objcopy.  Try "man objcopy" and then take a look at
the "--only-keep-debug" option.  It'll give you a whole recipe for doing
splitdebug.  The suffix used for the debug symbols is arbitrary.  If
people have other another suffix besides ".ko.debug" then we could
presumably support that too...

For portage (which is the packaging system used by Chrome OS) split debug
is supported by default (and the suffix is .ko.debug).  ...and so in
Chrome OS we always get the installed elf files stripped and then the
symbols stashed away.

At the moment we don't actually use the normal portage magic to do this
for the kernel though since it affects our ability to get good stack dumps
in the kernel.  We instead pass a script as "strip" [1].

[1] https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/refs/heads/master/eclass/cros-kernel/strip_splitdebug

Link: http://lkml.kernel.org/r/20190730234052.148744-1-dianders@chromium.org
Signed-off-by: Douglas Anderson 
Reviewed-by: Stephen Boyd 
Reviewed-by: Jan Kiszka 
Cc: Kieran Bingham 
Cc: Jason Wessel 
Cc: Daniel Thompson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: find vmlinux where it was before

2019-05-15T02:52:51+00:00

Patch series "gdb script for kconfig and timer list".

This is a handful of changes to the kernel's gdb scripts to do some more
debugging with kgdb.  The first patch allows the vmlinux to be reloaded
from where it was specified on the command line so that this set of
scripts can be used from anywhere.  The second patch adds a script to
dump the config.gz to a file on the host debugging machine.  The third
patch adds some rb tree utilities and the last patch uses those rb tree
walking utilities to dump out the contents of /proc/timer_list from a
system under debug.

This patch (of 5):

If I run 'gdb ' and there's the vmlinux-gdb.py file
there I can properly see symbols and use the lx commands provided by the
GDB scripts.  But once I run 'lx-symbols' at the command prompt, gdb
reloads the vmlinux symbols assuming that this script was run from the
directory that has vmlinux at the root.  That isn't always true, but we
could just look and see what symbols were already loaded and use that
instead.  Let's do that so this can work by being invoked anywhere.

Link: http://lkml.kernel.org/r/20190325184522.260535-2-swboyd@chromium.org
Signed-off-by: Stephen Boyd 
Cc: Douglas Anderson 
Cc: Nikolay Borisov 
Cc: Kieran Bingham 
Cc: Jan Kiszka 
Cc: Jackie Liu 
Cc: Jason Wessel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: Perform path expansion to lx-symbol's arguments

2016-07-15T05:54:27+00:00

Python doesn't do automatic expansion of paths.  In case one passes path
of the from ~/foo/bar the gdb scripts won't automatically expand that
and as a result the symbols files won't be loaded.

Fix this by explicitly expanding all paths which begin with "~"

Link: http://lkml.kernel.org/r/1467127337-11135-5-git-send-email-kieran@bingham.xyz
Signed-off-by: Nikolay Borisov 
Signed-off-by: Kieran Bingham 
Reviewed-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: account for changes in module data structure

2016-03-22T22:36:02+00:00

Commit 7523e4dc5057 ("module: use a structure to encapsulate layout.")
factored out the module_layout structure.  Adjust the symbol loader and
the lsmod command to this.

Signed-off-by: Jan Kiszka 
Reviewed-by: Kieran Bingham 
Tested-by: Kieran Bingham  (qemu-{ARM,x86})
Cc: Rusty Russell 
Cc: Jiri Kosina 
Cc: Jason Wessel 
Cc: 	[4.4+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: fix PEP8 compliance

2015-07-01T02:44:58+00:00

Signed-off-by: Thiébaud Weksteen 
Signed-off-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds