C2y will standardize countof as the macro that Emacs uses the name
ARRAYELTS for. Switch to the standard name, which is supported
by GCC 16+, by Clang 21, and by the Gnulib stdcountof-h module already
in use for compilers that do not support countof.
Also, use countof in a few places where we missed using ARRAYELTS.
* admin/coccinelle/arrayelts.cocci: Suggest countof, not ARRAYELTS.
* admin/merge-gnulib (GNULIB_MODULES): Add stdcountof-h,
as it is now a direct rather than an indirect dependency.
* exec/trace.c, src/lisp.h, src/sfnt.c: Include <stdcountof.h>.
(ARRAYELTS): Remove. All uses replaced by countof.
* lib-src/ebrowse.c, lib-src/etags.c, lib-src/make-docfile.c:
* lib-src/seccomp-filter.c, lwlib/lwlib-Xaw.c:
Prefer <stdcountof.h> and countof to doing things by hand.
* exec/exec.c (format_pid): Simplify. No need for a local array.
(exec_0): Shrink local buffer.
If names are too long, fail instead of silently truncating them.
Be cautious in case symlink is zero length (shouldn’t be possible
in Android, but it’s easy to be safe).
* exec/config-mips.m4.in (DADDI2, DADDI3): Disable at-clobbering
by assembler macros expressly.
* exec/loader-mips64el.s: Adapt from loader-mipsel.s.
* exec/configure.ac (exec_cv_as_daddi): Properly escape reg
names.
* exec/exec.c (struct exec_jump_command, exec_0): Don't define
or set `fpu_mode' if __LP64__.
* exec/exec.h (struct exec_tracee): New field `callno'.
* exec/trace.c (process_system_call): Always record the current
system call number in TRACEE lest it should be required once it
has been overwritten upon the syscall's completion.
(seccomp_system_call): Likewise.
(after_fork): Clear `tracee->callno'.
* exec/exec.c (insert_args, exec_0): On non-MIPS systems, copy
NAME and its length to the loader area. State that MIPS support
is not yet available (though it will be pending the availability
of a functioning emulator).
* exec/loader-aarch64.s (_start):
* exec/loader-armeabi.s (_start):
* exec/loader-x86.s (_start):
* exec/loader-x86_64.s (_start): Displace auxv, environ, and
argv to create sufficient space for the provided file name, and
copy the file name there. Replace AT_EXECFN to refer to this
space.
* exec/trace.c (process_vm_readv, process_vm_writev): New
function pointers. Attempt to load them on recent Android
systems when `exec' was not linked with a sufficiently
up-to-date libc.
(read_memory, user_copy): Always use process_vm_readv and
process_vm_writev if available.
(handle_openat): Write trailing NULL byte of filename to user
buffer.
(exec_init): Attempt to dlsym process_vm_readv and
process_vm_writev.
* etc/NEWS: Update correspondingly.
* exec/Makefile.in (config-mips.m4): Don't define rule
or predicate $(LOADOBJS) on it elsewhere than on MIPS.
* exec/README: Direct developers to GDB.
* exec/trace.c (finish_exec): Resume the tracee after reporting
an error in `exec'.
(after_fork): If seccomp is enabled on Android, and the kernel
is 4.7 or earlier, detect whether revisions to the sequencing of
seccomp events have been backported from 4.8.
(exec_waitpid): Resume the process with PTRACE_CONT after
receiving an unknown signal.
(exec_init): Cease disabling seccomp on Android kernels earlier
than 4.8.
* exec/configure.ac (REENTRANT): Remove option for reentrancy.
(PROGRAM_COUNTER, HAVE_SECCOMP): Define register providing the
program counter and enable seccomp if its headers are available.
* exec/exec.c (write_load_command): Avoid defining unused
variable.
(exec_0): Remove code specific to REENTRANT configurations.
* exec/exec.h (struct exec_tracee) <exec_data, data_size>: New
fields for loader instructions and their size.
* exec/exec1.c (main): Call exec_init before forking.
* exec/mipsel-user.h (ELF_NGREG): Delete definition.
(struct mipsel_regs): Reduce number of gregs to 32, but
introduce separate fields for special registers.
* exec/trace.c (use_seccomp_p): New variable; defile to false if
!HAVE_SECCOMP.
(remove_tracee): Cease providing for non-reentrant
configurations. Release executable data if present.
(handle_clone_prepare): Likewise. Resume process with
PTRACE_CONT if seccomp-based interception is enabled.
(handle_clone, check_signal): Resume processes as above.
(handle_exec): Divide into two functions, with only rewriting
the system call and generating instructions for the loader
remaining in the first, and copying such instructions into the
loader's stack removed into a new function, `finish_exec'.
(finish_exec): New function.
(handle_readlinkat, handle_openat): Abolish non-REENTRANT
configurations.
(process_system_call): Divide exec system calls into two phases,
disambiguated by the value of tracee->waiting_for_syscall. Typo
fixes. Accommodate syscall-exit-stops where the signal was
initially intercepted by `seccomp_system_call'.
(interesting_syscalls): New array.
(ARRAYELTS): New macro.
(seccomp_system_call, establish_seccomp_filter): New function.
(tracing_execve) [HAVE_SECCOMP]: Establish a seccomp filter if
this is to be enabled.
(after_fork): Provide PTRACE_O_TRACESECCOMP. Resume process
with PTRACE_CONT if seccomp-based interception is enabled.
(exec_waitpid): Resume process with PTRACE_CONT if seccomp-based
interception is enabled. Dispatch stops identifying as
PTRACE_EVENT_SECCOMP to `seccomp_system_call'.
(exec_init): Establish whether it is possible to enable seccomp.
* exec/configure.ac (USER_SWORD): New macro.
* exec/exec.c (format_pid): Export this function.
* exec/exec.h:
* exec/trace.c (canon_path): New function.
(handle_readlinkat, handle_openat): Test complete file name
against /proc/self/exe, and further check for /proc/pid/exe.
* exec/configure.ac (OPEN_SYSCALL, OPENAT_SYSCALL): Define new
macros.
* exec/exec.h (struct exec_tracee): New field `sp'.
* exec/trace.c (handle_openat): New function.
(process_system_call): If handle_openat executes successfully,
save the unmodified stack pointer within the tracee structure to
be restored once the system call completes.
* exec/trace.c (process_system_call) <READLINKAT_SYSCALL>:
Examine tracee->waiting_for_syscall and avoid rewriting user
arguments if a system call is presently being executed by the
kernel. Reported by Romário Rios <romariorios@protonmail.com>.
* exec/exec.h (struct exec_tracee): New field `new_child'.
Also, make `waiting_for_syscall' a bitfield.
* exec/trace.c (PTRACE_GETEVENTMSG): New declaration.
(MAX_TRACEES): Bump to 4096.
(handle_clone_prepare): New function.
(handle_clone): If required, set `new_child' and wait for a
ptrace event describing the parent to arrive.
(after_fork): Clear new field.
(exec_waitpid): Upon a ptrace event describing a clone, create
the child's tracee if it doesn't already exist. Otherwise, copy
over the parent's cmdline and start running it.
* exec/trace.c (check_signal): New function.
(handle_exec, process_system_call): Handle signal-delivery-stop
while waiting synchronously for syscall completion.
* exec/config.h.in: Autoheader.
* exec/configure.ac: Check for siginfo_t.si_syscall.
* exec/trace.c (exec_waitpid): If SIGSYS is received, and caused by
seccomp, drop it should the call number be the invalid system call
used by Emacs.
* exec/config.h.in: Autoheader.
* exec/configure.ac: Use system extensions.
(HAVE_PROCESS_VM): Define if process_vm_readv and
process_vm_writev are available.
* exec/trace.c (read_memory, user_copy): Implement in terms of
process_vm if possible.
* exec/config.h.in (__bool_true_false_are_defined):
* exec/configure.ac (REENTRANT): New definition.
(READLINKAT_SYSCALL, READLINK_SYSCALL): New defines. Set on all
hosts.
* exec/exec.c (MIN, MAX): Remove redundant declarations. Move
to config.h.
(exec_0): Copy name of executable into NAME when !REENTRANT.
* exec/exec.h (struct exec_tracee): New struct `exec_file'.
* exec/trace.c (remove_tracee, handle_exec, handle_readlinkat)
(process_system_call, after_fork): Handle readlinkat system
calls.
