Commit Graph

10 Commits

Author SHA1 Message Date
Yao Xingtao d5866a7a4e contrib/plugins/execlog: Fix compiler warning
1. The g_pattern_match_string() is deprecated when glib2 version >= 2.70.
   Use g_pattern_spec_match_string() instead to avoid this problem.

2. The type of second parameter in g_ptr_array_add() is
   'gpointer' {aka 'void *'}, but the type of reg->name is 'const char*'.
   Cast the type of reg->name to 'gpointer' to avoid this problem.

compiler warning message:

  contrib/plugins/execlog.c:330:17: warning: ‘g_pattern_match_string’
  is deprecated: Use 'g_pattern_spec_match_string' instead [-Wdeprecated-declarations]
    330 |                 if (g_pattern_match_string(pat, rd->name) ||
        |                 ^~
  In file included from /usr/include/glib-2.0/glib.h:67,
                   from contrib/plugins/execlog.c:9:
  /usr/include/glib-2.0/glib/gpattern.h:57:15: note: declared here
     57 | gboolean      g_pattern_match_string   (GPatternSpec *pspec,
        |               ^~~~~~~~~~~~~~~~~~~~~~
  contrib/plugins/execlog.c:331:21: warning: ‘g_pattern_match_string’
  is deprecated: Use 'g_pattern_spec_match_string' instead [-Wdeprecated-declarations]
    331 |                     g_pattern_match_string(pat, rd_lower)) {
        |                     ^~~~~~~~~~~~~~~~~~~~~~
  /usr/include/glib-2.0/glib/gpattern.h:57:15: note: declared here
     57 | gboolean      g_pattern_match_string   (GPatternSpec *pspec,
        |               ^~~~~~~~~~~~~~~~~~~~~~
  contrib/plugins/execlog.c:339:63: warning: passing argument 2 of
  ‘g_ptr_array_add’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
    339 |                             g_ptr_array_add(all_reg_names, reg->name);
        |                                                            ~~~^~~~~~
  In file included from /usr/include/glib-2.0/glib.h:33:
  /usr/include/glib-2.0/glib/garray.h:198:62: note: expected
  ‘gpointer’ {aka ‘void *’} but argument is of type ‘const char *’
    198 |                                            gpointer          data);
        |                                            ~~~~~~~~~~~~~~~~~~^~~~

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2210
Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
Message-ID: <20240326015257.21516-1-yaoxt.fnst@fujitsu.com>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2024-03-26 14:32:51 +01:00
Alex Bennée af6e4e0a22 contrib/plugins: extend execlog to track register changes
With the new plugin register API we can now track changes to register
values. Currently the implementation is fairly dumb which will slow
down if a large number of register values are being tracked. This
could be improved by only instrumenting instructions which mention
registers we are interested in tracking.

Example usage:

  ./qemu-aarch64 -D plugin.log -d plugin \
     -cpu max,sve256=on \
     -plugin contrib/plugins/libexeclog.so,reg=sp,reg=z\* \
     ./tests/tcg/aarch64-linux-user/sha512-sve

will display in the execlog any changes to the stack pointer (sp) and
the SVE Z registers.

As testing registers every instruction will be quite a heavy operation
there is an additional flag which attempts to optimise the register
tracking by only instrumenting instructions which are likely to change
its value. This relies on the QEMU disassembler showing up the register
names in disassembly so is an explicit opt-in.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Based-On:  <20231025093128.33116-19-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-27-alex.bennee@linaro.org>
2024-02-28 09:11:42 +00:00
Alex Bennée 9e096a76c7 contrib/plugins: fix imatch
We can't directly save the ephemeral imatch from argv as that memory
will get recycled.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-26-alex.bennee@linaro.org>
2024-02-28 09:11:42 +00:00
Akihiko Odaki 1063693e1c contrib/plugins: Use GRWLock in execlog
execlog had the following comment:
> As we could have multiple threads trying to do this we need to
> serialise the expansion under a lock. Threads accessing already
> created entries can continue without issue even if the ptr array
> gets reallocated during resize.

However, when the ptr array gets reallocated, the other threads may have
a stale reference to the old buffer. This results in use-after-free.

Use GRWLock to properly fix this issue.

Fixes: 3d7caf145e ("contrib/plugins: add execlog to log instruction execution and memory access")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230912224107.29669-5-akihiko.odaki@daynix.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-12-alex.bennee@linaro.org>
2023-10-11 08:46:33 +01:00
Alex Bennée 4025874199 plugins: fix memory leak while parsing options
It was hard to track down this leak as it was an internal allocation
by glib and the backtraces did not give much away. The autofree was
freeing the allocation with g_free() but not taking care of the
individual strings. They should have been freed with g_strfreev()
instead.

Searching the glib source code for the correct string free function
led to:

  G_DEFINE_AUTO_CLEANUP_FREE_FUNC(GStrv, g_strfreev, NULL)

and indeed if you read to the bottom of the documentation page you
will find:

  typedef gchar** GStrv;

  A typedef alias for gchar**. This is mostly useful when used together with g_auto().

So fix up all the g_autofree g_strsplit case that smugly thought they
had de-allocation covered.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-21-alex.bennee@linaro.org>
2023-07-03 12:51:58 +01:00
Alex Bennée 14fd492b89 contrib/plugins: protect execlog's last_exec expansion
We originally naively treated expansion as safe because we expected
each new CPU/thread to appear in order. However the -M raspi2 model
triggered a case where a new high cpu_index thread started executing
just before a smaller one.

Clean this up by converting the GArray into the simpler GPtrArray and
then holding a lock for the expansion.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Alexandre Iooss <erdnaxe@crans.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221027183637.2772968-29-alex.bennee@linaro.org>
2022-10-31 20:37:59 +00:00
Alex Bennée 8c1f1020d6 contrib/plugins: reset skip when matching in execlog
The purpose of the matches was to only track the execution of
instructions we care about. Without resetting skip to the value at the
start of the block we end up dumping all instructions after the match
with the consequent load on the instrumentation.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Alexandre Iooss <erdnaxe@crans.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220929114231.583801-40-alex.bennee@linaro.org>
2022-10-06 11:53:40 +01:00
Alex Bennée b7855bf65f plugins: extend execlog to filter matches
Sometimes the whole execlog is just two much so add the ability to
filter by instruction opcode or address.

[AJB: this shows for example

 qemu-system-aarch64 -display none -serial mon:stdio \
   -M virt -cpu max \
   -semihosting-config enable=on \
   -kernel ./tests/tcg/aarch64-softmmu/memory-sve \
   -plugin ./contrib/plugins/libexeclog.so,ifilter=st1w,afilter=0x40001808 -d plugin -D plugin.out

the st1w SVE instruction is not instrumenting its stores.]

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alexandre Iooss <erdnaxe@crans.org>
Cc: Robert Henry <robhenry@microsoft.com>
Cc: Aaron Lindsay <aaron@os.amperecomputing.com>
Message-Id: <20220929114231.583801-36-alex.bennee@linaro.org>
2022-10-06 11:53:40 +01:00
Mahmoud Mandour b40310616d plugins/execlog: removed unintended "s" at the end of log lines.
Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210803151428.125323-1-ma.mandourr@gmail.com>
Message-Id: <20210806141015.2487502-2-alex.bennee@linaro.org>
Cc: qemu-stable@nongnu.org
2021-09-02 11:29:34 +01:00
Alexandre Iooss 3d7caf145e contrib/plugins: add execlog to log instruction execution and memory access
Log instruction execution and memory access to a file.
This plugin can be used for reverse engineering or for side-channel analysis
using QEMU.

Signed-off-by: Alexandre Iooss <erdnaxe@crans.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210702081307.1653644-2-erdnaxe@crans.org>
Message-Id: <20210709143005.1554-35-alex.bennee@linaro.org>
2021-07-14 15:54:13 +01:00