[PATCH v3 2/4] Replace __libc_multiple_threads with __libc_single_threaded
Yann Droneaud
ydroneaud@opteya.com
Wed Jun 22 11:04:37 GMT 2022
Hi,
Le 21/06/2022 à 22:32, Adhemerval Zanella via Libc-alpha a écrit :
> And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL,
> since header inclusion single-thread.h is in the wrong order, the define
> needs to come before including sysdeps/unix/sysdep.h. The macro
> is now moved to a per-arch single-threade.h header.
>
> The SINGLE_THREAD_P is used on some more places.
>
> Checked on aarch64-linux-gnu and x86_64-linux-gnu.
> ---
> nptl/Makefile | 1 -
> nptl/allocatestack.c | 6 ----
> nptl/libc_multiple_threads.c | 28 -------------------
> nptl/pthread_cancel.c | 2 +-
> posix/fork.c | 2 +-
> sysdeps/nptl/setxid.h | 2 +-
> .../unix/sysv/linux/aarch64/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/aarch64/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/alpha/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/arc/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/arc/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/arm/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/arm/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/hppa/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/hppa/sysdep.h | 2 --
> .../sysv/linux/microblaze/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/microblaze/sysdep.h | 2 --
> sysdeps/unix/sysv/linux/s390/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/s390/sysdep.h | 3 --
> sysdeps/unix/sysv/linux/single-thread.h | 11 ++++----
> .../unix/sysv/linux/x86_64/single-thread.h | 2 ++
> sysdeps/unix/sysv/linux/x86_64/sysdep.h | 2 --
> 22 files changed, 22 insertions(+), 61 deletions(-)
> delete mode 100644 nptl/libc_multiple_threads.c
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/arc/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/arm/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/hppa/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/microblaze/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/s390/single-thread.h
> create mode 100644 sysdeps/unix/sysv/linux/x86_64/single-thread.h
>
> diff --git a/nptl/Makefile b/nptl/Makefile
> index b585663974..3d2ce8af8a 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -50,7 +50,6 @@ routines = \
> events \
> futex-internal \
> libc-cleanup \
> - libc_multiple_threads \
> lowlevellock \
> nptl-stack \
> nptl_deallocate_tsd \
> diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
> index 01a282f3f6..98f5f6dd85 100644
> --- a/nptl/allocatestack.c
> +++ b/nptl/allocatestack.c
> @@ -292,9 +292,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
>
> /* This is at least the second thread. */
> pd->header.multiple_threads = 1;
> -#ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> -#endif
>
> #ifdef NEED_DL_SYSINFO
> SETUP_THREAD_SYSINFO (pd);
> @@ -413,9 +410,6 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp,
>
> /* This is at least the second thread. */
> pd->header.multiple_threads = 1;
> -#ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> -#endif
>
> #ifdef NEED_DL_SYSINFO
> SETUP_THREAD_SYSINFO (pd);
> diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c
> deleted file mode 100644
> index 0c2dc33d0d..0000000000
> --- a/nptl/libc_multiple_threads.c
> +++ /dev/null
> @@ -1,28 +0,0 @@
> -/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
> - This file is part of the GNU C Library.
> -
> - The GNU C Library is free software; you can redistribute it and/or
> - modify it under the terms of the GNU Lesser General Public
> - License as published by the Free Software Foundation; either
> - version 2.1 of the License, or (at your option) any later version.
> -
> - The GNU C Library is distributed in the hope that it will be useful,
> - but WITHOUT ANY WARRANTY; without even the implied warranty of
> - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - Lesser General Public License for more details.
> -
> - You should have received a copy of the GNU Lesser General Public
> - License along with the GNU C Library; if not, see
> - <https://www.gnu.org/licenses/>. */
> -
> -#include <pthreadP.h>
> -
> -#if IS_IN (libc)
> -# ifndef TLS_MULTIPLE_THREADS_IN_TCB
> -/* Variable set to a nonzero value either if more than one thread runs or ran,
> - or if a single-threaded process is trying to cancel itself. See
> - nptl/descr.h for more context on the single-threaded process case. */
> -int __libc_multiple_threads;
> -libc_hidden_data_def (__libc_multiple_threads)
> -# endif
> -#endif
> diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
> index e67b2df5cc..459317df49 100644
> --- a/nptl/pthread_cancel.c
> +++ b/nptl/pthread_cancel.c
> @@ -161,7 +161,7 @@ __pthread_cancel (pthread_t th)
> points get executed. */
> THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
> #ifndef TLS_MULTIPLE_THREADS_IN_TCB
> - __libc_multiple_threads = 1;
> + __libc_single_threaded_internal = 0;
> #endif
> }
> while (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling, &oldval,
> diff --git a/posix/fork.c b/posix/fork.c
> index 987916a175..cee5ae83c8 100644
> --- a/posix/fork.c
> +++ b/posix/fork.c
> @@ -45,7 +45,7 @@ __libc_fork (void)
> requirement for fork (Austin Group tracker issue #62) this is
> best effort to make is async-signal-safe at least for single-thread
> case. */
> - bool multiple_threads = __libc_single_threaded_internal == 0;
> + bool multiple_threads = !SINGLE_THREAD_P;
> uint64_t lastrun;
>
> lastrun = __run_prefork_handlers (multiple_threads);
> diff --git a/sysdeps/nptl/setxid.h b/sysdeps/nptl/setxid.h
> index b87cad7b18..3a412179ac 100644
> --- a/sysdeps/nptl/setxid.h
> +++ b/sysdeps/nptl/setxid.h
> @@ -29,7 +29,7 @@
> #define INLINE_SETXID_SYSCALL(name, nr, args...) \
> ({ \
> int __result; \
> - if (!__libc_single_threaded_internal) \
> + if (!SINGLE_THREAD_P) \
> { \
> struct xid_command __cmd; \
> __cmd.syscall_no = __NR_##name; \
> diff --git a/sysdeps/unix/sysv/linux/aarch64/single-thread.h b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> index 3b230dccf1..f1853e012f 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> @@ -164,8 +164,6 @@
> # define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
> # define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> # undef INTERNAL_SYSCALL_RAW
> # define INTERNAL_SYSCALL_RAW(name, nr, args...) \
> ({ long _sys_result; \
> diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> index 3051a744b4..77ec2b5400 100644
> --- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
> @@ -32,8 +32,6 @@
> #undef SYS_ify
> #define SYS_ify(syscall_name) __NR_##syscall_name
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #ifdef __ASSEMBLER__
> #include <asm/pal.h>
> #include <alpha/regdef.h>
> diff --git a/sysdeps/unix/sysv/linux/arc/single-thread.h b/sysdeps/unix/sysv/linux/arc/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arc/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
> index 29b0e0161c..d0c1a78381 100644
> --- a/sysdeps/unix/sysv/linux/arc/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
> @@ -132,8 +132,6 @@ L (call_syscall_err): ASM_LINE_SEP \
>
> #else /* !__ASSEMBLER__ */
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> # if IS_IN (libc)
> extern long int __syscall_error (long int);
> hidden_proto (__syscall_error)
> diff --git a/sysdeps/unix/sysv/linux/arm/single-thread.h b/sysdeps/unix/sysv/linux/arm/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arm/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
> index 7bdd218063..1f270b961e 100644
> --- a/sysdeps/unix/sysv/linux/arm/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
> @@ -408,8 +408,6 @@ __local_syscall_error: \
> #define INTERNAL_SYSCALL_NCS(number, nr, args...) \
> INTERNAL_SYSCALL_RAW (number, nr, args)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* __ASSEMBLER__ */
>
> #endif /* linux/arm/sysdep.h */
> diff --git a/sysdeps/unix/sysv/linux/hppa/single-thread.h b/sysdeps/unix/sysv/linux/hppa/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/hppa/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
> index 42f7705852..2f339a4bd6 100644
> --- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
> @@ -474,6 +474,4 @@ L(pre_end): ASM_LINE_SEP \
> #define PTR_MANGLE(var) (void) (var)
> #define PTR_DEMANGLE(var) (void) (var)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* _LINUX_HPPA_SYSDEP_H */
> diff --git a/sysdeps/unix/sysv/linux/microblaze/single-thread.h b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/microblaze/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/microblaze/sysdep.h b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> index dfd6312506..fda78f6467 100644
> --- a/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/microblaze/sysdep.h
> @@ -308,8 +308,6 @@ SYSCALL_ERROR_LABEL_DCL: \
> # define PTR_MANGLE(var) (void) (var)
> # define PTR_DEMANGLE(var) (void) (var)
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> #undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
> #define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
>
> diff --git a/sysdeps/unix/sysv/linux/s390/single-thread.h b/sysdeps/unix/sysv/linux/s390/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/s390/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
> index 78c7e8c7e2..2d0a26779c 100644
> --- a/sysdeps/unix/sysv/linux/s390/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
> @@ -93,9 +93,6 @@
> #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
> #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
>
> -#define SINGLE_THREAD_BY_GLOBAL 1
> -
> -
> #define VDSO_NAME "LINUX_2.6.29"
> #define VDSO_HASH 123718585
>
> diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h
> index 4529a906d2..30dde4e81a 100644
> --- a/sysdeps/unix/sysv/linux/single-thread.h
> +++ b/sysdeps/unix/sysv/linux/single-thread.h
> @@ -19,6 +19,10 @@
> #ifndef _SINGLE_THREAD_H
> #define _SINGLE_THREAD_H
>
> +#ifndef __ASSEMBLER__
> +# include <sys/single_threaded.h>
> +#endif
> +
> /* The default way to check if the process is single thread is by using the
> pthread_t 'multiple_threads' field. However, for some architectures it is
> faster to either use an extra field on TCB or global variables (the TCB
> @@ -27,16 +31,11 @@
> The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread
> check to use global variables instead of the pthread_t field. */
>
> -#ifndef __ASSEMBLER__
> -extern int __libc_multiple_threads;
> -libc_hidden_proto (__libc_multiple_threads)
> -#endif
> -
> #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
SINGLE_THREAD_BY_GLOBAL doesn't seem to be defined after this patch, so can it this be updated as:
- #if !defined SINGLE_THREAD_BY_GLOBAL || IS_IN (rtld)
+ #if IS_IN(rtld)
> # define SINGLE_THREAD_P \
> (THREAD_GETMEM (THREAD_SELF, header.multiple_threads) == 0)
> #else
> -# define SINGLE_THREAD_P (__libc_multiple_threads == 0)
> +# define SINGLE_THREAD_P (__libc_single_threaded_internal != 0)
> #endif
>
> #define RTLD_SINGLE_THREAD_P SINGLE_THREAD_P
> diff --git a/sysdeps/unix/sysv/linux/x86_64/single-thread.h b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
> new file mode 100644
> index 0000000000..a5d3a2aaf4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86_64/single-thread.h
> @@ -0,0 +1,2 @@
> +#define SINGLE_THREAD_BY_GLOBAL
> +#include_next <single-thread.h>
> diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> index e1ce3b62eb..740abefcfd 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> @@ -379,8 +379,6 @@
>
> # define HAVE_CLONE3_WRAPPER 1
>
> -# define SINGLE_THREAD_BY_GLOBAL 1
> -
> #endif /* __ASSEMBLER__ */
>
>
Regards.
--
Yann Droneaud
OPTEYA
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