XPG4.2 defines the siginfo_t type, but not union sigval or its
contents (which were added in the 1993 edition of POSIX.1), resulting
in namespace violations for sigval, sival_int and sival_ptr for
signal.h and sys/wait.h for that standard because those headers
incorrectly expose those names in that case.
This patch fixes this problem. The public type in this case is union
sigval, but various places in the headers use the sigval_t name for
it; direct uses of union sigval are already properly guarded or in
headers not in XPG4.2. Now, sigval_t, although not a standard name,
does seem to be widely used outside glibc. The approach taken by this
patch is to make installed headers use the name __sigval_t instead.
__sigval_t is then defined to either union sigval or union __sigval
(where union __sigval has __-prefixed member names as well), depending
on whether there are any namespace issues with the union sigval name
and its members. In the case where union __sigval is used, sigval_t
is not defined at all, to avoid the problem of sigval_t having a C++
mangled name that depends on feature test macros. sigval_t is still
defined by signal.h if __USE_MISC (reflecting the nonstandard nature
of that name).
Tested for x86_64.
[BZ #21944]
* signal/bits/types/__sigval_t.h: New file.
* signal/Makefile (headers): Add bits/types/__sigval_t.h.
* signal/bits/types/sigval_t.h: Include <bits/types/__sigval_t.h>
and define sigval_t using __sigval_t.
* include/bits/types/__sigval_t.h: New file.
* bits/types/sigevent_t.h: Include <bits/types/__sigval_t.h>
instead of <bits/types/__sigval_t.h>.
(struct sigevent): Use __sigval_t instead of sigval_t.
* bits/types/siginfo_t.h: Include <bits/types/__sigval_t.h>
instead of <bits/types/__sigval_t.h>.
(siginfo_t): Use __sigval_t instead of sigval_t.
* sysdeps/unix/sysv/linux/bits/types/sigevent_t.h: Include
<bits/types/__sigval_t.h> instead of <bits/types/__sigval_t.h>.
(struct sigevent): Use __sigval_t instead of sigval_t.
* sysdeps/unix/sysv/linux/bits/types/siginfo_t.h: Include
<bits/types/__sigval_t.h> instead of <bits/types/__sigval_t.h>.
(siginfo_t): Use __sigval_t instead of sigval_t.
* signal/signal.h [__USE_MISC]: Include <bits/types/sigval_t.h>.
glibc defines the stack_t type with the tag struct sigaltstack. This
is not permitted by POSIX; sigaltstack is only reserved with file
scope in the namespace of ordinary identifiers, not the tag namespace,
and in the case where stack_t is obtained from ucontext.h rather than
signal.h, it's not reserved with file scope at all.
This patch removes the tag accordingly and updates uses in glibc of
struct sigaltstack. This is similar to the removal of the "struct
siginfo" tag a few years ago: C++ name mangling changes are an
unavoidable consequence. A NEWS item is added to note the changed
mangling. There is inevitably some risk of breaking builds of
anything that relies on the struct sigaltstack name (though the first
few hits I looked at from codesearch.debian.net generally seemed to
involve code that could use the stack_t name conditionally, so
depending on how they determine the conditionals they may work with
glibc not defining the struct tag anyway).
Tested for x86_64 and x86, and with build-many-glibcs.py.
[BZ #21517]
* bits/types/stack_t.h (stack_t): Remove struct tag.
* sysdeps/unix/sysv/linux/bits/types/stack_t.h (stack_t):
Likewise.
* sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h (stack_t):
Likewise.
* debug/segfault.c (install_handler): Use stack_t instead of
struct sigaltstack.
* hurd/hurd/signal.h (struct hurd_sigstate): Likewise.
* hurd/trampoline.c (_hurd_setup_sighandler): Likewise.
* include/signal.h (__sigaltstack): Likwise.
* signal/sigaltstack.c (__sigaltstack): Likewise.
* signal/signal.h (sigaltstack): Likewise.
* sysdeps/mach/hurd/i386/signal-defines.sym
(SIGALTSTACK__SS_SP__OFFSET): Likewise.
(SIGALTSTACK__SS_SIZE__OFFSET): Likewise.
(SIGALTSTACK__SS_FLAGS__OFFSET): Likewise.
* sysdeps/mach/hurd/sigaltstack.c (__sigaltstack): Likewise.
* sysdeps/mach/hurd/sigstack.c (sigstack): Likewise.
* sysdeps/unix/sysv/linux/alpha/sys/procfs.h (struct
elf_prstatus): Likewise.
* sysdeps/unix/sysv/linux/hppa/____longjmp_chk.c (CHECK_SP):
Likewise.
* sysdeps/unix/sysv/linux/ia64/sys/procfs.h (struct elf_prstatus):
Likewise.
* sysdeps/unix/sysv/linux/m68k/____longjmp_chk.c (CHECK_SP):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/procfs.h (struct
elf_prstatus): Likewise.
* sysdeps/unix/sysv/linux/sh/sys/procfs.h (struct elf_prstatus):
Likewise.
* sysdeps/unix/sysv/linux/sys/procfs.h (struct elf_prstatus):
Likewise.
The types affected are __sig_atomic_t, sig_atomic_t, __sigset_t,
sigset_t, sigval_t, sigevent_t, and siginfo_t. __sig_atomic_t is a
scalar, so it's now directly available from bits/types.h. The others
get bits/types/ headers.
Side effects include: There have been small changes to which
non-signal headers expose which subset of the signal-related types.
A couple of architectures' nested siginfo_t fields had to be renamed
to prevent undesired macro expansion. Internal code that wants to
manipulate signal masks must now include <sigsetops.h> (which is not
installed) and should be aware that __sigaddset, __sigandset,
__sigdelset, __sigemptyset, and __sigorset no longer return a value
(unlike the public API). Relatedly, the public signal.h no longer
declares any of those functions. The obsolete sigmask() macro no
longer has a system-specific definition -- in the cases where it
matters, it didn't work anyway.
New Linux architectures should create bits/siginfo-arch.h and/or
bits/siginfo-consts-arch.h to customize their siginfo_t, rather than
duplicating everything in bits/siginfo.h (which no longer exists).
Add new __SI_* macros if necessary. Ports to other operating systems
are strongly encouraged to generalize this scheme further.
* bits/sigevent-consts.h
* bits/siginfo-consts.h
* bits/types/__sigset_t.h
* bits/types/sigevent_t.h
* bits/types/siginfo_t.h
* sysdeps/unix/sysv/linux/bits/sigevent-consts.h
* sysdeps/unix/sysv/linux/bits/siginfo-consts.h
* sysdeps/unix/sysv/linux/bits/types/__sigset_t.h
* sysdeps/unix/sysv/linux/bits/types/sigevent_t.h
* sysdeps/unix/sysv/linux/bits/types/siginfo_t.h:
New system-dependent bits headers.
* sysdeps/unix/sysv/linux/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/mips/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/sparc/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo-arch.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo-consts-arch.h
* sysdeps/unix/sysv/linux/x86/bits/siginfo-arch.h:
New Linux-only system-dependent bits headers.
* signal/bits/types/sig_atomic_t.h
* signal/bits/types/sigset_t.h
* signal/bits/types/sigval_t.h:
New non-system-dependent bits headers.
* sysdeps/generic/sigsetops.h
* sysdeps/unix/sysv/linux/sigsetops.h:
New internal headers.
* include/bits/types/sig_atomic_t.h
* include/bits/types/sigset_t.h
* include/bits/types/sigval_t.h:
New wrappers.
* signal/sigsetops.h
* bits/siginfo.h
* bits/sigset.h
* sysdeps/unix/sysv/linux/bits/siginfo.h
* sysdeps/unix/sysv/linux/bits/sigset.h
* sysdeps/unix/sysv/linux/ia64/bits/siginfo.h
* sysdeps/unix/sysv/linux/mips/bits/siginfo.h
* sysdeps/unix/sysv/linux/s390/bits/siginfo.h
* sysdeps/unix/sysv/linux/sparc/bits/siginfo.h
* sysdeps/unix/sysv/linux/tile/bits/siginfo.h
* sysdeps/unix/sysv/linux/x86/bits/siginfo.h:
Deleted.
* signal/Makefile, sysdeps/unix/sysv/linux/Makefile:
Update lists of installed headers.
* posix/bits/types.h: Define __sig_atomic_t here.
* signal/signal.h: Use the new bits headers; no need to handle
__need_sig_atomic_t nor __need_sigset_t. Don't use __sigmask
to define sigmask.
* include/signal.h: No need to handle __need_sig_atomic_t
nor __need_sigset_t. Don't define __sigemptyset.
* io/sys/poll.h, setjmp/setjmp.h
* sysdeps/arm/sys/ucontext.h, sysdeps/generic/sys/ucontext.h
* sysdeps/i386/sys/ucontext.h, sysdeps/m68k/sys/ucontext.h
* sysdeps/mach/hurd/i386/bits/sigcontext.h
* sysdeps/mips/sys/ucontext.h, sysdeps/powerpc/novmxsetjmp.h
* sysdeps/pthread/bits/sigthread.h
* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h
* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h
* sysdeps/unix/sysv/linux/mips/sys/ucontext.h
* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
* sysdeps/unix/sysv/linux/s390/sys/ucontext.h
* sysdeps/unix/sysv/linux/sh/sys/ucontext.h
* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h
* sysdeps/unix/sysv/linux/tile/sys/ucontext.h
* sysdeps/unix/sysv/linux/x86/sys/ucontext.h:
Use bits/types/__sigset_t.h.
* misc/sys/select.h, posix/spawn.h
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
* sysdeps/unix/sysv/linux/sys/epoll.h
* sysdeps/unix/sysv/linux/sys/signalfd.h:
Use bits/types/sigset_t.h.
* resolv/netdb.h, rt/mqueue.h: Use bits/types/sigevent_t.h.
* rt/aio.h: Use bits/types/sigevent_t.h and bits/sigevent-consts.h.
* socket/sys/socket.h: Don't include bits/sigset.h.
* login/utmp_file.c, shadow/lckpwdf.c, signal/sigandset.c
* signal/sigisempty.c, stdlib/abort.c, sysdeps/posix/profil.c
* sysdeps/posix/sigignore.c, sysdeps/posix/sigintr.c
* sysdeps/posix/signal.c, sysdeps/posix/sigset.c
* sysdeps/posix/sprofil.c, sysdeps/posix/sysv_signal.c
* sysdeps/unix/sysv/linux/nptl-signals.h:
Include sigsetops.h.
* signal/sigaddset.c, signal/sigandset.c, signal/sigdelset.c
* signal/sigorset.c, stdlib/abort.c, sysdeps/posix/sigignore.c
* sysdeps/posix/signal.c, sysdeps/posix/sigset.c:
__sigaddset, __sigandset, __sigdelset, __sigemptyset, __sigorset
now return no value.
* signal/sigaddset.c, signal/sigdelset.c, signal/sigismem.c
Include <errno.h>, <signal.h>, and <sigsetops.h> instead of
"sigsetops.h".
* signal/sigsetops.c: Explicitly define __sigismember,
__sigaddset, and __sigdelset as compatibility symbols.
* signal/Versions: Correct commentary on __sigpause,
__sigaddset, __sigdelset, __sigismember.
* inet/rcmd.c: Include sigsetops.h. Convert old code using
__sigblock/__sigsetmask to use __sigprocmask and friends.
bits/sigstack.h contains four things: the legacy struct sigstack type,
the preferred stack_t type, the SS_* enum values and macros for signal
stack sizes.
These vary in different ways between glibc configurations; in
particular, the stack sizes vary much more than any of the other
pieces. Furthermore, these pieces have different standard namespace
rules for when they should be visible (not currently visible in
conform/ results both because the relevant tests are XFAILed for
sys/ucontext.h namespace issues, and because some of the expectations
are incorrect in the same way as the headers, e.g. neither
expectations nor headers reflect that current POSIX no longer has
either the sigstack function or the sigstack structure).
To reduce duplication of identical definitions, and facilitate
namespace fixes without requiring the same feature test macro
conditions to be repeated in many versions of the same header, this
patch splits bits/sigstack.h up into four headers. It keeps the stack
size macros, while new bits/types/struct_sigstack.h,
bits/types/stack_t.h and bits/ss_flags.h are added for the other
pieces. bits/types/struct_sigstack.h is the same everywhere,
bits/types/stack_t.h has three variants different in the order of the
structure elements (generic = MIPS Linux, and other Linux), and
bits/ss_flags.h has generic and Linux variants.
This patch includes the new headers everywhere that included
<bits/sigstack.h>, so should cause no difference to what any public
header defines. Subsequent namespace fixes would then remove or
condition some of those includes.
There should be no conflicts with Zack's changes to signal.h types,
beyond the trivial conflict of both making additions to
signal/Makefile's headers list; the two patches affect disjoint sets
of types and other definitions.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* bits/ss_flags.h: New file.
* bits/types/stack_t.h: Likewise.
* include/bits/types/struct_sigstack.h: Likewise.
* signal/bits/types/struct_sigstack.h: Likewise.
* sysdeps/unix/sysv/linux/bits/ss_flags.h: Likewise.
* sysdeps/unix/sysv/linux/bits/types/stack_t.h: Likewise.
* sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h: Likewise.
* signal/Makefile (headers): Add bits/types/struct_sigstack.h,
bits/types/stack_t.h and bits/ss_flags.h.
* signal/signal.h [__USE_XOPEN_EXTENDED || __USE_XOPEN2K8]:
Include <bits/types/struct_sigstack.h>, <bits/types/stack_t.h> and
<bits/ss_flags.h>.
* bits/sigstack.h (struct sigstack): Remove.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/aarch64/bits/sigstack.h
(struct sigstack): Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/alpha/bits/sigstack.h (struct sigstack):
Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/bits/sigstack.h (struct sigstack):
Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/mips/bits/sigstack.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/sigstack.h (struct sigstack):
Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h
(struct sigstack): Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sigstack.h (struct sigstack):
Likewise.
(stack_t): Likewise.
(SS_ONSTACK): Likewise.
(SS_DISABLE): Likewise.
* sysdeps/arm/sys/ucontext.h: Include
<bits/types/struct_sigstack.h>, <bits/types/stack_t.h> and
<bits/ss_flags.h>.
* sysdeps/generic/sys/ucontext.h: Likewise.
* sysdeps/i386/sys/ucontext.h: Likewise.
* sysdeps/m68k/sys/ucontext.h: Likewise.
* sysdeps/mips/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/arm/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/bits/sigcontext.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/mips/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/s390/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/sh/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/tile/sys/ucontext.h: Likewise.
* sysdeps/unix/sysv/linux/x86/sys/ucontext.h: Likewise.
Joseph Myers
Zack Weinberg