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Simon Marchi 183be22290 gdb, gdbserver: make target_waitstatus safe
I stumbled on a bug caused by the fact that a code path read
target_waitstatus::value::sig (expecting it to contain a gdb_signal
value) while target_waitstatus::kind was TARGET_WAITKIND_FORKED.  This
meant that the active union field was in fact
target_waitstatus::value::related_pid, and contained a ptid.  The read
signal value was therefore garbage, and that caused GDB to crash soon
after.  Or, since that GDB was built with ubsan, this nice error
message:

    /home/simark/src/binutils-gdb/gdb/linux-nat.c:1271:12: runtime error: load of value 2686365, which is not a valid value for type 'gdb_signal'

Despite being a large-ish change, I think it would be nice to make
target_waitstatus safe against that kind of bug.  As already done
elsewhere (e.g. dynamic_prop), validate that the type of value read from
the union matches what is supposed to be the active field.

 - Make the kind and value of target_waitstatus private.
 - Make the kind initialized to TARGET_WAITKIND_IGNORE on
   target_waitstatus construction.  This is what most users appear to do
   explicitly.
 - Add setters, one for each kind.  Each setter takes as a parameter the
   data associated to that kind, if any.  This makes it impossible to
   forget to attach the associated data.
 - Add getters, one for each associated data type.  Each getter
   validates that the data type fetched by the user matches the wait
   status kind.
 - Change "integer" to "exit_status", "related_pid" to "child_ptid",
   just because that's more precise terminology.
 - Fix all users.

That last point is semi-mechanical.  There are a lot of obvious changes,
but some less obvious ones.  For example, it's not possible to set the
kind at some point and the associated data later, as some users did.
But in any case, the intent of the code should not change in this patch.

This was tested on x86-64 Linux (unix, native-gdbserver and
native-extended-gdbserver boards).  It was built-tested on x86-64
FreeBSD, NetBSD, MinGW and macOS.  The rest of the changes to native
files was done as a best effort.  If I forgot any place to update in
these files, it should be easy to fix (unless the change happens to
reveal an actual bug).

Change-Id: I0ae967df1ff6e28de78abbe3ac9b4b2ff4ad03b7
2021-10-21 16:13:56 -04:00
bfd Automatic date update in version.in 2021-10-21 00:00:22 +00:00
binutils Avoid -Waddress warnings in readelf 2021-10-21 22:09:21 +10:30
config
contrib
cpu
elfcpp PATCH [4/4] arm: Add Tag_PACRET_use build attribute 2021-08-17 14:49:42 +02:00
etc etc: switch to automake 2021-09-09 23:30:12 -04:00
gas Re: s12z/disassembler: call memory_error_func when appropriate 2021-10-14 13:08:46 +10:30
gdb gdb, gdbserver: make target_waitstatus safe 2021-10-21 16:13:56 -04:00
gdbserver gdb, gdbserver: make target_waitstatus safe 2021-10-21 16:13:56 -04:00
gdbsupport Fix format_pieces selftest on Windows 2021-10-19 13:14:48 -06:00
gnulib gnulib: import various network functions 2021-09-08 17:48:09 -04:00
gold PR28417, std::string no longer allows accepting nullptr_t 2021-10-21 07:54:27 +10:30
gprof configure: regenerate in all projects that use libtool.m4 2021-09-27 20:31:24 +01:00
include RISC-V: Add support for Zbs instructions 2021-10-07 17:09:25 +08:00
intl
ld -Waddress warning in ldelf.c 2021-10-21 22:10:28 +10:30
libbacktrace Copy in libbacktrace from gcc 2021-09-28 12:21:21 +01:00
libctf libctf, lookup: fix bounds of pptrtab lookup 2021-09-27 20:31:26 +01:00
libdecnumber
libiberty
opcodes z80/disassembler: call memory_error_func when appropriate 2021-10-11 14:07:03 +01:00
readline
sim sim: add --info-target for listing supported BFD targets 2021-10-04 02:19:58 -04:00
texinfo
zlib configure: regenerate in all projects that use libtool.m4 2021-09-27 20:31:24 +01:00
.cvsignore
.gitattributes
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ar-lib
ChangeLog src-release.sh: add libbacktrace to GDB_SUPPORT_DIRS 2021-09-28 12:21:21 +01:00
compile
config-ml.in
config.guess
config.rpath
config.sub
configure top-level configure: setup target_configdirs based on repository 2021-09-28 12:21:21 +01:00
configure.ac top-level configure: setup target_configdirs based on repository 2021-09-28 12:21:21 +01:00
COPYING
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libtool.m4 libtool.m4: fix nm BSD flag detection 2021-09-27 20:31:23 +01:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def gdb: Add a dependency between gdb and libbacktrace 2021-09-28 12:21:21 +01:00
Makefile.in gdb: Add a dependency between gdb and libbacktrace 2021-09-28 12:21:21 +01:00
Makefile.tpl
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missing
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src-release.sh src-release.sh: add libbacktrace to GDB_SUPPORT_DIRS 2021-09-28 12:21:21 +01:00
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