Commit Graph

38 Commits

Author SHA1 Message Date
Matheus Castanho
ebae2f5a6f Add build option to disable usage of scv on powerpc
Commit 68ab82f566 added support for the scv
syscall ABI on powerpc.  Since then systems that have kernel and processor
support started using scv.  However adding the proper support for a new syscall
ABI requires changes to several other projects (e.g. qemu, valgrind, strace,
kernel), which are gradually receiving support.

Meanwhile, having a way to disable scv on glibc at build time can be useful for
distros that may encounter conflicts with projects that still do not support the
scv ABI, buying time until proper support is added.

This commit adds a --disable-scv option that disables scv support and uses sc
for all syscalls, like before commit 68ab82f566.

Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-06-10 16:23:25 -03:00
Florian Weimer
527c89cd32 powerpc64: Select POWER9 machine for the scv instruction
It is not available with the baseline ISA.

Fixes commit 68ab82f566
("powerpc: Runtime selection between sc and scv for syscalls").

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2021-01-22 10:45:27 +01:00
Paul Eggert
2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00
Matheus Castanho
41f013cef2 powerpc: Use scv instruction on clone when available
clone already uses r31 to temporarily save input arguments before doing the
syscall, so we use a different register to read from the TCB. We can also avoid
allocating another stack frame, which is not needed since we can simply extend
the usage of the red zone.

Tested-by: Lucas A. M. Magalhães <lamm@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-12-30 18:26:33 -03:00
Matheus Castanho
68ab82f566 powerpc: Runtime selection between sc and scv for syscalls
Linux kernel v5.9 added support for system calls using the scv
instruction for POWER9 and later.  The new codepath provides better
performance (see below) if compared to using sc.  For the
foreseeable future, both sc and scv mechanisms will co-exist, so this
patch enables glibc to do a runtime check and use scv when it is
available.

Before issuing the system call to the kernel, we check hwcap2 in the TCB
for PPC_FEATURE2_SCV to see if scv is supported by the kernel.  If not,
we fallback to sc and keep the old behavior.

The kernel implements a different error return convention for scv, so
when returning from a system call we need to handle the return value
differently depending on the instruction we used to enter the kernel.

For syscalls implemented in ASM, entry and exit are implemented by
different macros (PSEUDO and PSEUDO_RET, resp.), which may be used in
sequence (e.g. for templated syscalls) or with other instructions in
between (e.g. clone).  To avoid accessing the TCB a second time on
PSEUDO_RET to check which instruction we used, the value read from
hwcap2 is cached on a non-volatile register.

This is not needed when using INTERNAL_SYSCALL macro, since entry and
exit are bundled into the same inline asm directive.

The dynamic loader may issue syscalls before the TCB has been setup
so it always uses sc with no extra checks.  For the static case, there
is no compile-time way to determine if we are inside startup code,
so we also check the value of the thread pointer before effectively
accessing the TCB.  For such situations in which the availability of
scv cannot be determined, sc is always used.

Support for scv in syscalls implemented in their own ASM file (clone and
vfork) will be added later. For now simply use sc as before.

Average performance over 1M calls for each syscall "type":
  - stat: C wrapper calling INTERNAL_SYSCALL
  - getpid: templated ASM syscall
  - syscall: call to gettid using syscall function

  Standard:
     stat : 1.573445 us / ~3619 cycles
   getpid : 0.164986 us / ~379 cycles
  syscall : 0.162743 us / ~374 cycles

  With scv:
     stat : 1.537049 us / ~3535 cycles <~ -84 cycles  / -2.32%
   getpid : 0.109923 us / ~253 cycles  <~ -126 cycles / -33.25%
  syscall : 0.116410 us / ~268 cycles  <~ -106 cycles / -28.34%

Tested on powerpc, powerpc64, powerpc64le (with and without scv)

Tested-by: Lucas A. M. Magalhães <lamm@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-12-30 18:26:25 -03:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
Joseph Myers
04277e02d7 Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2019-01-01 00:11:28 +00:00
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00
Adhemerval Zanella
3f823e87cc Call exit directly in clone (BZ #21512)
On aarch64, alpha, arm, hppa, mips, nios2, powerpc, sh, sparc, tile,
and x86_64 the clone syscall jumps to _exit after the child execution
and the function ends the process execution by calling exit_group.
This behavior have a small issue where threads created with
CLONE_THREAD using clone syscall directly will eventually exit the
whole group altogether instead of just the thread created.  Also,
s390, microblaze, ia64, i386, and m68k differs by calling exit
syscall directly.

This patch changes all architectures to call the exit syscall
directly, as for s390, microblaze, ia64, i386, and m68k.  This do not
have change glibc internal behavior in any sort, since the only
usage of clone implementation in posix_spawn calls _exit directly
in the created child (fork uses a direct call to clone).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
powerpc-linux-gnu, powerpc64le-linux-gnu, sparc64-linux-gnu,
and sparcv9-linux-gnu.

	[BZ #21512]
	* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Call exit
	syscall instead of jump to _exit.
	(CLONE_VM_BIT): Remove unused define.
	(CLONE_VM): Likewise.
	(CLONE_THREAD_BIT): Likewise.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S (CLONE_VM): Likewise.
	* sysdeps/unix/sysv/linux/ia64/clone2.S (__clone2): Call exit
	syscall instead of jump to _exit.
	* sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone):
	Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone):
	Likewise.
	(CLONE_VM): Remove unused define.
	(CLONE_THREAD): Likewise.
	* sysdeps/unix/sysv/linux/sh/clone.S  (__clone): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise.
	(CLONE_VM): Remove unused define.
	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-clone3.
	* sysdeps/unix/sysv/linux/tst-clone3.c: New file.

Fix
2017-06-26 17:52:20 -03:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Adhemerval Zanella
c579f48edb Remove cached PID/TID in clone
This patch remove the PID cache and usage in current GLIBC code.  Current
usage is mainly used a performance optimization to avoid the syscall,
however it adds some issues:

  - The exposed clone syscall will try to set pid/tid to make the new
    thread somewhat compatible with current GLIBC assumptions.  This cause
    a set of issue with new workloads and usecases (such as BZ#17214 and
    [1]) as well for new internal usage of clone to optimize other algorithms
    (such as clone plus CLONE_VM for posix_spawn, BZ#19957).

  - The caching complexity also added some bugs in the past [2] [3] and
    requires more effort of each port to handle such requirements (for
    both clone and vfork implementation).

  - Caching performance gain in mainly on getpid and some specific
    code paths.  The getpid performance leverage is questionable [4],
    either by the idea of getpid being a hotspot as for the getpid
    implementation itself (if it is indeed a justifiable hotspot a
    vDSO symbol could let to a much more simpler solution).

    Other usage is mainly for non usual code paths, such as pthread
    cancellation signal and handling.

For thread creation (on stack allocation) the code simplification in fact
adds some performance gain due the no need of transverse the stack cache
and invalidate each element pid.

Other thread usages will require a direct getpid syscall, such as
cancellation/setxid signal, thread cancellation, thread fail path (at
create_thread), and thread signal (pthread_kill and pthread_sigqueue).
However these are hardly usual hotspots and I think adding a syscall is
justifiable.

It also simplifies both the clone and vfork arch-specific implementation.
And by review each fork implementation there are some discrepancies that
this patch also solves:

  - microblaze clone/vfork does not set/reset the pid/tid field
  - hppa uses the default vfork implementation that fallback to fork.
    Since vfork is deprecated I do not think we should bother with it.

The patch also removes the TID caching in clone. My understanding for
such semantic is try provide some pthread usage after a user program
issue clone directly (as done by thread creation with CLONE_PARENT_SETTID
and pthread tid member).  However, as stated before in multiple discussions
threads, GLIBC provides clone syscalls without further supporting all this
semantics.

I ran a full make check on x86_64, x32, i686, armhf, aarch64, and powerpc64le.
For sparc32, sparc64, and mips I ran the basic fork and vfork tests from
posix/ folder (on a qemu system).  So it would require further testing
on alpha, hppa, ia64, m68k, nios2, s390, sh, and tile (I excluded microblaze
because it is already implementing the patch semantic regarding clone/vfork).

[1] https://codereview.chromium.org/800183004/
[2] https://sourceware.org/ml/libc-alpha/2006-07/msg00123.html
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=15368
[4] http://yarchive.net/comp/linux/getpid_caching.html

	* sysdeps/nptl/fork.c (__libc_fork): Remove pid cache setting.
	* nptl/allocatestack.c (allocate_stack): Likewise.
	(__reclaim_stacks): Likewise.
	(setxid_signal_thread): Obtain pid through syscall.
	* nptl/nptl-init.c (sigcancel_handler): Likewise.
	(sighandle_setxid): Likewise.
	* nptl/pthread_cancel.c (pthread_cancel): Likewise.
	* sysdeps/unix/sysv/linux/pthread_kill.c (__pthread_kill): Likewise.
	* sysdeps/unix/sysv/linux/pthread_sigqueue.c (pthread_sigqueue):
	Likewise.
	* sysdeps/unix/sysv/linux/createthread.c (create_thread): Likewise.
	* sysdeps/unix/sysv/linux/getpid.c: Remove file.
	* nptl/descr.h (struct pthread): Change comment about pid value.
	* nptl/pthread_getattr_np.c (pthread_getattr_np): Remove thread
	pid assert.
	* sysdeps/unix/sysv/linux/pthread-pids.h (__pthread_initialize_pids):
	Do not set pid value.
	* nptl_db/td_ta_thr_iter.c (iterate_thread_list): Remove thread
	pid cache check.
	* nptl_db/td_thr_validate.c (td_thr_validate): Likewise.
	* sysdeps/aarch64/nptl/tcb-offsets.sym: Remove pid offset.
	* sysdeps/alpha/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/arm/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/hppa/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/i386/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/ia64/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/m68k/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/microblaze/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/mips/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/nios2/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/s390/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/sh/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/sparc/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/tile/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/clone.S: Remove pid and tid caching.
	* sysdeps/unix/sysv/linux/alpha/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/arm/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/hppa/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/ia64/clone2.S: Likewise.
	* sysdeps/unix/sysv/linux/mips/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/nios2/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sh/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/tile/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/vfork.S: Remove pid set and reset.
	* sysdeps/unix/sysv/linux/alpha/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/arm/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/ia64/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/m68k/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/m68k/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/mips/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/nios2/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/sh/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/tile/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/tst-clone2.c (f): Remove direct pthread
	struct access.
	(clone_test): Remove function.
	(do_test): Rewrite to take in consideration pid is not cached anymore.
2016-11-24 19:38:51 -02:00
Tulio Magno Quites Machado Filho
ce193f551e powerpc: Fix TOC stub on powerpc64 clone()
Use a function call to _exit() so that the linker can create a TOC stub
instead of just a branch.

Tested on powerpc64.
2016-10-28 19:13:21 -02:00
Adhemerval Zanella
0cb313f7cb Fix clone (CLONE_VM) pid/tid reset (BZ#19957)
As discussed in libc-alpha [1] current clone with CLONE_VM (without
CLONE_THREAD set) will reset the pthread pid/tid fields to -1.  The
issue is since memory is shared between the parent and child it will
clobber parent's cached pid/tid leading to internal inconsistencies
if the value is not restored.

And even it is restored it may lead to racy conditions when between
set/restore a thread might invoke pthread function that validate the
pthread with INVALID_TD_P/INVALID_NOT_TERMINATED_TD_P and thus get
wrong results.

As stated in BZ19957, previously reports of this behaviour was close
with EWONTFIX due the fact usage of clone outside glibc is tricky
since glibc requires consistent internal pthread, while using clone
directly may not provide it. However since now posix_spawn uses
clone (CLONE_VM) to fixes various issues related to previous vfork
usage this issue requires fixing.

The vfork implementation also does something similar, but instead
it negates and restores only the *pid* field and functions that
might access its value know to handle such case (getpid, raise
and pthread ones that uses INVALID_TD_P/INVALID_NOT_TERMINATED_TD_P
macros that check only *tid* field).  Also vfork does not call
__clone directly, instead calling either __NR_vfork or __NR_clone
directly.

So this patch removes this clone behavior by avoiding setting
the pthread pid/tid field for CLONE_VM. There is no need to
check for CLONE_THREAD, since the minimum supported kernel in all
architecture implies that CLONE_VM must be used with CLONE_THREAD,
otherwise clone returns EINVAL.

Instead of current approach of:

   int clone(int (*fn)(void *), void *child_stack, int flags, ...)
      [...]
      if (flags & CLONE_THREAD)
        goto do_syscall;
      pid_t new_value;
      if (flags & CLONE_VM)
        new_value = -1;
      else
        new_value = getpid ();
      THREAD_SETMEM (THREAD_SELF, pid, new_value);
      THREAD_SETMEM (THREAD_SELF, tid, new_value);

    do_syscall:
      [...]

The new approach uses:

   int clone(int (*fn)(void *), void *child_stack, int flags, ...)
      [...]
      if (flags & CLONE_VM)
        goto do_syscall;
      pid_t new_value = getpid ();
      THREAD_SETMEM (THREAD_SELF, pid, new_value);
      THREAD_SETMEM (THREAD_SELF, tid, new_value);

    do_syscall:
      [...]

It also removes the linux tst-getpid2.c test which expects the previous
behavior and instead add another clone test.

Tested on x86_64, i686, x32, powerpc64le, aarch64, armhf, s390, and
s390x. I also did limited check on mips32 and sparc64 (using the new
added test).

I also got reviews from both m68k, hppa, and tile.  So I presume for
these architecture the patch works.

The fixes for alpha, microblaze, sh, ia64, and nio2 have not been
tested.

[1] https://sourceware.org/ml/libc-alpha/2016-04/msg00307.html

	* sysdeps/unix/sysv/linux/Makefile [$(subdir) == nptl] (test): Remove
	tst-getpid2.
	(test): Add tst-clone2.
	* sysdeps/unix/sysv/linux/tst-clone2.c: New file.
	* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Do not change
	pid/tid fields for CLONE_VM.
	* sysdeps/unix/sysv/linux/arm/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/mips/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/tst-getpid2.c: Remove file.
2016-04-29 18:19:30 -03:00
Adhemerval Zanella
9ff72da471 posix: New Linux posix_spawn{p} implementation
This patch implements a new posix_spawn{p} implementation for Linux.  The main
difference is it uses the clone syscall directly with CLONE_VM and CLONE_VFORK
flags and a direct allocated stack.  The new stack and start function solves
most the vfork limitation (possible parent clobber due stack spilling).  The
remaning issue are related to signal handling:

  1. That no signal handlers must run in child context, to avoid corrupt
     parent's state.
  2. Child must synchronize with parent to enforce stack deallocation and
     to possible return execv issues.

The first one is solved by blocking all signals in child, even NPTL-internal
ones (SIGCANCEL and SIGSETXID).  The second issue is done by a stack allocation
in parent and a synchronization with using a pipe or waitpid (in case or error).
The pipe has the advantage of allowing the child signal an exec error (checked
with new tst-spawn2 test).

There is an inherent race condition in pipe2 usage for architectures that do not
support the syscall directly.  In such cases the a pipe plus fctnl is used
instead and it may lead to file descriptor leak in parent (as decribed by fcntl
documentation).

The child process stack is allocate with a mmap with MAP_STACK flag using
default architecture stack size.  Although it is slower than use a stack buffer
from parent, it allows some slack for the compatibility code to run scripts
with no shebang (which may use a buffer with size depending of argument list
count).

Performance should be similar to the vfork default posix implementation and
way faster than fork path (vfork on mostly linux ports are basically
clone with CLONE_VM plus CLONE_VFORK).  The only difference is the syscalls
required for the stack allocation/deallocation.

It fixes BZ#10354, BZ#14750, and BZ#18433.

Tested on i386, x86_64, powerpc64le, and aarch64.

	[BZ #14750]
	[BZ #10354]
	[BZ #18433]
	* include/sched.h (__clone): Add hidden prototype.
	(__clone2): Likewise.
	* include/unistd.h (__dup): Likewise.
	* posix/Makefile (tests): Add tst-spawn2.
	* posix/tst-spawn2.c: New file.
	* sysdeps/posix/dup.c (__dup): Add hidden definition.
	* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/i386/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/ia64/clone2.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/m68k/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/microblaze/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/sh/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise.
	* sysdeps/unix/sysv/linux/nptl-signals.h
	(____nptl_is_internal_signal): New function.
	* sysdeps/unix/sysv/linux/spawni.c: New file.
2016-03-07 11:53:47 +07:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Adhemerval Zanella
8464c2a110 PowerPC: Consolidate NPTL/non versions of clone 2014-05-26 11:41:46 -05:00
Allan McRae
d4697bc93d Update copyright notices with scripts/update-copyrights 2014-01-01 22:00:23 +10:00
Ulrich Weigand
8b8a692cfd PowerPC64 ELFv2 ABI 4/6: Stack frame layout changes
This updates glibc for the changes in the ELFv2 relating to the
stack frame layout.  These are described in more detail here:
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01149.html
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01146.html

Specifically, the "compiler and linker doublewords" were removed,
which has the effect that the save slot for the TOC register is
now at offset 24 rather than 40 to the stack pointer.

In addition, a function may now no longer necessarily assume that
its caller has set up a 64-byte register save area its use.

To address the first change, the patch goes through all assembler
files and replaces immediate offsets in instructions accessing the
ABI-defined stack slots by symbolic offsets.  Those already were
defined in ucontext_i.sym and used in some of the context routines,
but that doesn't really seem like the right place for those defines.

The patch instead defines those symbolic offsets in sysdeps.h,
in two variants for the old and new ABI, and uses them systematically
in all assembler files, not just the context routines.

The second change only affected a few assembler files that used
the save area to temporarily store some registers.  In those
cases where this happens within a leaf function, this patch
changes the code to store those registers to the "red zone"
below the stack pointer.  Otherwise, the functions already allocate
a stack frame, and the patch changes them to add extra space in
these frames as temporary space for the ELFv2 ABI.
2013-12-04 07:41:39 -06:00
Ulrich Weigand
d31beafa8e PowerPC64 ELFv2 ABI 1/6: Code refactoring
This is the first patch to support the new ELFv2 ABI in glibc.

As preparation, this patch simply refactors some of the powerpc64 assembler
code to move all code related to creating function descriptors (.opd section)
or using function descriptors (function pointer call) into a central place
in sysdep.h.

Note that most locations creating .opd entries were already using macros
in sysdep.h, this patch simply extends this to the remaining places.

No relevant change in generated code expected.
2013-12-04 07:41:38 -06:00
Joseph Myers
2d67d91ac0 Remove powerpc64 bounded-pointers code. 2013-03-06 00:10:21 +00:00
Joseph Myers
568035b787 Update copyright notices with scripts/update-copyrights. 2013-01-02 19:05:09 +00:00
Paul Eggert
59ba27a63a Replace FSF snail mail address with URLs. 2012-02-09 23:18:22 +00:00
Alan Modra
bebff237c5 PowerPC64 ABI fixes 2010-08-12 09:19:19 -07:00
Roland McGrath
97d901a672 * sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Terminate FDE
before syscall.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
2006-04-04 07:01:16 +00:00
Roland McGrath
3e7e947f6b * sysdeps/powerpc/powerpc32/fpu/fprsave.S: Add cfi_offset for spilling
of non-volatile floating-point registers to the stack (fp14-fp31).
	* sysdeps/powerpc/powerpc32/gprsave0.S: Add cfi_offset for spilling of
	non-volatile general-purpose registers to the stack (gpr13-gpr31).
	* sysdeps/powerpc/powerpc64/dl-trampoline.S: Add cfi_offset
	for non-volatiles gpr30 - grp31 spilled to the stack.
	* sysdeps/powerpc/powerpc64/memcpy.S: Add cfi_offset for non-volatile
	gpr31 spill to the stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/setcontext-common.S:
	Add cfi_offset for non-volatile gpr31 spill to the stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Add cfi_offset
	for non-volatiles gpr28 - grp31 spilled to the stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/getcontext.S: Add
	cfi_adjust_cfa_offset when a frame is stacked.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/setcontext.S:
	(__novec_setcontext) : Add cfi_offset for non-volatile gpr31 spill
	add LR saved to the stack.  Add cfi_adjust_cfa_offset when frame is
	stacked.
	(__setcontext) : Add cfi_offset for non-volatile gpr31 spill to
	the stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/swapcontext.S:
	(__novec_swapcontext) : Add cfi_offset for non-volatile gpr31 spill
	add LR saved to the stack.
	(__swapcontext) : Add cfi_offset for non-volatile gpr31 spill add LR
	saved to the stack.  Add cfi_adjust_cfa_offset when frame is stacked.
2006-03-16 11:49:03 +00:00
Ulrich Drepper
a7e915610a * elf/tst-tls8.c (do_test): Use $ORIGIN in module names.
2006-01-03  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/generic/sysdep.h (cfi_same_value): Define macro.

	* sysdeps/powerpc/powerpc32/dl-trampoline.S (_dl_runtime_resolve,
	_dl_profile_resolve): Add CFI directives for stack and LR save.
	Save LR in LRSAVE of previous frame per ABI.
	* sysdeps/powerpc/powerpc32/fpu/__longjmp-common.S: Add CFI directives
	for LR save.
	* sysdeps/powerpc/powerpc32/lshift.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/makecontext.S
	(__makecontext, __novec_makecontext): Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_ceil.S: Add CFI directive
	for LR save to register.
	* sysdeps/powerpc/powerpc32/fpu/s_ceilf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_floor.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_floorf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_rint.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_rintf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_round.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_roundf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_trunc.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_truncf.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/setjmp-common.S: Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_copysign.S: Add CFI directive
	for stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise.
	* sysdeps/powerpc/powerpc32/ppc-mcount.S: Add CFI directives for stack
	and LR save.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/brk.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/getcontext-common.S:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/setcontext-common.S:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_lround.S:  Likewise.  Don't use
	negative stack addressing.

	* sysdeps/powerpc/powerpc64/dl-trampoline.S (_dl_runtime_resolve,
	_dl_profile_resolve): Add CFI directives for stack and LR save.
	* sysdeps/powerpc/powerpc64/fpu/s_copysign.S: Add CFI directives
	for stack.
	* sysdeps/powerpc/powerpc64/ppc-mcount.S (_mcount): Add CFI
	directives for stack and LR save.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/brk.S (__brk): Add CFI
	directives for stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone): Add CFI
	directives for stack.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/getcontext.S
	(__getcontext, __novec_getcontext): Add CFI directives for stack
	and LR save.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S
	(__makecontext): Add CFI directives for stack and LR save.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/setcontext.S
	(__setcontext, __novec_setcontext): Add CFI directives for stack
	and LR save.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/swapcontext.S
	(__swapcontext, __novec_swapcontext):  Add CFI directives for stack
	and LR save.
2006-01-07 03:58:05 +00:00
Ulrich Drepper
a334319f65 (CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4. 2004-12-22 20:10:10 +00:00
Jakub Jelinek
0ecb606cb6 2.5-18.1 2007-07-12 18:26:36 +00:00
Ulrich Drepper
a2eae4ccb1 Correct stack alignment. Clean up flag bit tests. Remove redundent SP assignment. Add TOC register save/restore around function call. 2004-12-15 20:37:06 +00:00
Ulrich Drepper
f23673fc71 Update.
2004-12-15  Jakub Jelinek  <jakub@redhat.com>

	* nis/nis_domain_of_r.c (nis_domain_of_r): Use libnsl_hidden_def,
	not libnsl_hidden_proto.

	* sysdeps/unix/sysv/linux/s390/s390-32/clone.S (__clone): Add support
	for NPTL where the PID is stored at userlevel and needs to be reset
	when CLONE_THREAD is not used.
	* sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): Likewise.

	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone): Save
	and restore r2 around call to fn.
2004-12-15 17:45:55 +00:00
Ulrich Drepper
f05a41ebd3 .I think this code is more correct. 2004-12-15 09:14:28 +00:00
Ulrich Drepper
1f9d7c2739 Update.
2004-12-14  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Add support
	for pid caching in nptl.
2004-12-15 07:04:50 +00:00
Ulrich Drepper
865d953fc9 Update.
2004-10-06  Alan Modra  <amodra@bigpond.net.au>

	* sysdeps/powerpc/powerpc64/ppc-mcount.S (PROF): Don't undef.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/brk.S: Invoke CALL_MOUNT.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/getcontext.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/setcontext.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/socket.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/swapcontext.S: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/vfork.S: Likewise.
2004-12-14 21:25:41 +00:00
Ulrich Drepper
7062ca8f6c Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S [SHARED]: Use
	__GI__exit.
2004-04-01 21:14:56 +00:00
Roland McGrath
4fba8a3b3d 2003-03-10 Steven Munroe <sjmunroe@us.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Don't clobber R7.
	Copy extra params for NPTL to registers used in clone syscall.
2003-03-10 21:04:29 +00:00
Roland McGrath
cfc91acd41 2002-09-17 Steven Munroe <sjmunroe@us.ibm.com>
Ported to PowerPC64 running Linux.
	* sysdeps/powerpc/powerpc64/Dist: New file.
	* sysdeps/powerpc/powerpc64/Implies: New file.
	* sysdeps/powerpc/powerpc64/Makefile: New file.
	* sysdeps/powerpc/powerpc64/__longjmp.S: New file.
	* sysdeps/powerpc/powerpc64/atomicity.h: New file.
	* sysdeps/powerpc/powerpc64/backtrace.c: New file.
	* sysdeps/powerpc/powerpc64/bp-asm.h: New file.
	* sysdeps/powerpc/powerpc64/bsd-_setjmp.S: New file.
	* sysdeps/powerpc/powerpc64/bsd-setjmp.S: New file.
	* sysdeps/powerpc/powerpc64/dl-dtprocnum.h: New file.
	* sysdeps/powerpc/powerpc64/dl-lookupcfg.h: New file.
	* sysdeps/powerpc/powerpc64/dl-machine.c: New file.
	* sysdeps/powerpc/powerpc64/dl-machine.h: New file.
	* sysdeps/powerpc/powerpc64/memset.S: New file.
	* sysdeps/powerpc/powerpc64/ppc-mcount.S: New file.
	* sysdeps/powerpc/powerpc64/register-dump.h: New file.
	* sysdeps/powerpc/powerpc64/setjmp.S: New file.
	* sysdeps/powerpc/powerpc64/stpcpy.S: New file.
	* sysdeps/powerpc/powerpc64/strchr.S: New file.
	* sysdeps/powerpc/powerpc64/strcmp.S: New file.
	* sysdeps/powerpc/powerpc64/strcpy.S: New file.
	* sysdeps/powerpc/powerpc64/strlen.S: New file.
	* sysdeps/powerpc/powerpc64/elf/bzero.S: New file.
	* sysdeps/powerpc/powerpc64/elf/start.S: New file.
	* sysdeps/powerpc/powerpc64/fpu/s_copysign.S: New file.
	* sysdeps/powerpc/powerpc64/fpu/s_copysignf.S: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/Versions: New File.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/brk.S: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/glob64.c: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/socket.S: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/syscalls.list: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h: New file.
2002-09-17 23:50:03 +00:00