From eae96c1e2b02af0554bbae189af2c8091cb581bf Mon Sep 17 00:00:00 2001 From: Christophe Lyon Date: Wed, 4 Jul 2018 17:55:32 +0200 Subject: nptl: Disable fork and atfork on MMU-less systems. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit They do not work on MMU-less systems. For atfork, implement a hidden function that always returns EPERM. * libpthread/nptl/sysdeps/unix/sysv/linux/fork.c: Disable if __ARCH_USE_MMU__ is not defined. * libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c (__libc_pthread_init): Handle __ARCH_USE_MMU__. * libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c: Likewise. * libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c: Likewise. Signed-off-by: Mickaël Guêné Signed-off-by: Christophe Lyon --- libpthread/nptl/sysdeps/unix/sysv/linux/fork.c | 3 +++ .../nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c | 4 ++++ libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c | 14 +++++++++++++- .../nptl/sysdeps/unix/sysv/linux/unregister-atfork.c | 10 +++++++++- 4 files changed, 29 insertions(+), 2 deletions(-) diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c index 9b96152d6..429fb902e 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/fork.c @@ -28,6 +28,7 @@ #include #include +#ifdef __ARCH_USE_MMU__ unsigned long int *__fork_generation_pointer; @@ -206,3 +207,5 @@ fork (void) return pid; } libc_hidden_def(fork) + +#endif /* __ARCH_USE_MMU__ */ diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c b/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c index 0df9951a8..0cdbcfece 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/libc_pthread_init.c @@ -40,10 +40,14 @@ __libc_pthread_init ( void (*reclaim) (void)) { /* Remember the pointer to the generation counter in libpthread. */ +#ifdef __ARCH_USE_MMU__ __fork_generation_pointer = ptr; +#endif /* Called by a child after fork. */ +#ifdef __ARCH_USE_MMU__ __register_atfork (NULL, NULL, reclaim, NULL); +#endif #ifndef TLS_MULTIPLE_THREADS_IN_TCB return &__libc_multiple_threads; diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c index b745f9d71..55835e504 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/register-atfork.c @@ -24,6 +24,7 @@ #include +#ifdef __ARCH_USE_MMU__ /* Lock to protect allocation and deallocation of fork handlers. */ int __fork_lock = LLL_LOCK_INITIALIZER; @@ -118,6 +119,18 @@ __linkin_atfork (struct fork_handler *newp) while (catomic_compare_and_exchange_bool_acq (&__fork_handlers, newp, newp->next) != 0); } +#else +int +__register_atfork ( + void (*prepare) (void), + void (*parent) (void), + void (*child) (void), + void *dso_handle) +{ + return EPERM; +} +libc_hidden_def (__register_atfork) +#endif #if 0 libc_freeres_fn (free_mem) @@ -145,4 +158,3 @@ libc_freeres_fn (free_mem) } } #endif - diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c b/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c index 69e26210f..e958e7137 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/unregister-atfork.c @@ -22,7 +22,7 @@ #include #include - +#ifdef __ARCH_USE_MMU__ void __unregister_atfork ( void *dso_handle) @@ -120,3 +120,11 @@ __unregister_atfork ( deleted = deleted->next; } } +#else +void +__unregister_atfork ( + void *dso_handle) +{ + /* Nothing to do. */ +} +#endif -- cgit v1.2.3