linux-toradex.git/scripts/gdb/linux, branch v4.13-rc7

scripts/gdb: lx-dmesg: use explicit encoding=utf8 errors=replace

2017-07-12T23:26:01+00:00

Use errors=replace because it is never desirable for lx-dmesg to fail on
string decoding errors, not even if the log buffer is corrupt and we
show incorrect info.

The kernel will sometimes print utf8, for example the copyright symbol
from jffs2.  In order to make this work specify 'utf8' everywhere
because python2 otherwise defaults to 'ascii'.

In theory the second errors='replace' is not be required because
everything that can be decoded as utf8 should also be encodable back to
utf8.  But it's better to be extra safe here.  It's worth noting that
this is definitely not true for encoding='ascii', unknown characters are
replaced with U+FFFD REPLACEMENT CHARACTER and they fail to encode back
to ascii.

Link: http://lkml.kernel.org/r/acee067f3345954ed41efb77b80eebdc038619c6.1498481469.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez 
Acked-by: Jan Kiszka 
Cc: Jason Wessel 
Cc: Kieran Bingham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: lx-dmesg: cast log_buf to void* for addr fetch

2017-07-12T23:26:01+00:00

In some cases it is possible for the str() conversion here to throw
encoding errors because log_buf might not point to valid ascii.  For
example:

  (gdb) python print str(gdb.parse_and_eval("log_buf"))
  Traceback (most recent call last):
    File "", line 1, in 
  UnicodeEncodeError: 'ascii' codec can't encode character u'\u0303' in
  	position 24: ordinal not in range(128)

Avoid this by explicitly casting to (void *) inside the gdb expression.

Link: http://lkml.kernel.org/r/ba6f85dbb02ca980ebd0e2399b0649423399b565.1498481469.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez 
Reviewed-by: Jan Kiszka 
Cc: Jason Wessel 
Cc: Kieran Bingham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: add lx-fdtdump command

2017-07-12T23:26:00+00:00

lx-fdtdump dumps the flattened device tree passed to the kernel from the
bootloader to the filename specified as the command argument.  If no
argument is provided it defaults to fdtdump.dtb.  This then allows
further post processing on the machine running GDB.  The fdt header is
also also printed in the GDB console.  For example:

  (gdb) lx-fdtdump
  fdt_magic:         0xD00DFEED
  fdt_totalsize:     0xC108
  off_dt_struct:     0x38
  off_dt_strings:    0x3804
  off_mem_rsvmap:    0x28
  version:           17
  last_comp_version: 16
  Dumped fdt to fdtdump.dtb

  >fdtdump fdtdump.dtb | less

This command is useful as the bootloader can often re-write parts of the
device tree, and this can sometimes cause the kernel to not boot.

Link: http://lkml.kernel.org/r/1481280065-5336-2-git-send-email-kbingham@kernel.org
Signed-off-by: Peter Griffin 
Signed-off-by: Kieran Bingham 
Cc: Jason Wessel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: make lx-dmesg command work (reliably)

2017-06-02T22:07:38+00:00

lx-dmesg needs access to the log_buf symbol from printk.c.
Unfortunately, the symbol log_buf also exists in BPF's verifier.c and
hence gdb can pick one or the other.  If it happens to pick BPF's
log_buf, lx-dmesg doesn't work:

  (gdb) lx-dmesg
  Python Exception  Cannot access memory at address 0x0:
  Error occurred in Python command: Cannot access memory at address 0x0
  (gdb) p log_buf
  $15 = 0x0

Luckily, GDB has a way to deal with this, see
  https://sourceware.org/gdb/onlinedocs/gdb/Symbols.html

  (gdb) info variables ^log_buf$
  All variables matching regular expression "^log_buf$":

  File /kernel/bpf/verifier.c:
  static char *log_buf;

  File /kernel/printk/printk.c:
  static char *log_buf;
  (gdb) p 'verifier.c'::log_buf
  $1 = 0x0
  (gdb) p 'printk.c'::log_buf
  $2 = 0x811a6aa0 <__log_buf> ""
  (gdb) p &log_buf
  $3 = (char **) 0x8120fe40 
  (gdb) p &'verifier.c'::log_buf
  $4 = (char **) 0x8120fe40 
  (gdb) p &'printk.c'::log_buf
  $5 = (char **) 0x8048b7d0 

By being explicit about the location of the symbol, we can make lx-dmesg
work again.  While at it, do the same for the other symbols we need from
printk.c

Link: http://lkml.kernel.org/r/20170526112222.3414-1-git@andred.net
Signed-off-by: André Draszik 
Tested-by: Kieran Bingham 
Acked-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "scripts/gdb: add a Radix Tree Parser"

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

This reverts commit e127a73d41ac ("scripts/gdb: add a Radix Tree
Parser")

The python implementation of radix-tree was merged at the same time as
the radix-tree system was heavily reworked from commit e9256efcc8e3
("radix-tree: introduce radix_tree_empty") to 3bcadd6fa6c4 ("radix-tree:
free up the bottom bit of exceptional entries for reuse") and no longer
functions, but also prevents other gdb scripts from loading.

This functionality has not yet hit a release, so simply remove it for
now

Link: http://lkml.kernel.org/r/1467127337-11135-6-git-send-email-kieran@bingham.xyz
Signed-off-by: Kieran Bingham 
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: add constants.py to .gitignore

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

Since scripts/gdb/linux/constants.py is autogenerated, this should have
been added to .gitignore when it was introduced.

Fixes: f197d75fcad1 ("scripts/gdb: provide linux constants")
Link: http://lkml.kernel.org/r/1467127337-11135-4-git-send-email-kieran@bingham.xyz
Signed-off-by: Omar Sandoval 
Signed-off-by: Kieran Bingham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: rebuild constants.py on dependancy change

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

The autogenerated constants.py file was only being built on the initial
call, and if the constants.py.in file changed.  As we are utilising the
CPP hooks, we can successfully use the call if_changed_dep rules to
determine when to rebuild the file based on it's inclusions.

Link: http://lkml.kernel.org/r/1467127337-11135-3-git-send-email-kieran@bingham.xyz
Signed-off-by: Kieran Bingham 
Reported-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: silence 'nothing to do' message

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

The constants.py generation, involves a rule to link into the main
makefile.  This rule has no command and generates a spurious warning
message in the build logs when CONFIG_SCRIPTS_GDB is enabled.

Fix simply by giving a no-op action

Link: http://lkml.kernel.org/r/1467127337-11135-2-git-send-email-kieran@bingham.xyz
Signed-off-by: Kieran Bingham 
Reported-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

scripts/gdb: decode bytestream on dmesg for Python3

2016-05-24T00:04:14+00:00

The recent fixes to lx-dmesg, now allow the command to print
successfully on Python3, however the python interpreter wraps the bytes
for each line with a b'' marker.

To remove this, we need to decode the line, where .decode() will default
to 'UTF-8'

Link: http://lkml.kernel.org/r/d67ccf93f2479c94cb3399262b9b796e0dbefcf2.1462865983.git.jan.kiszka@siemens.com
Signed-off-by: Kieran Bingham 
Acked-by: Dom Cote 
Tested-by: Dom Cote 
Signed-off-by: Jan Kiszka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds