From: Rich Felker Date: Sat, 26 May 2012 02:44:34 +0000 (-0400) Subject: avoid using pthread cleanup push/pop in stdio when not needed X-Git-Tag: v0.9.1~22 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=3f25354e624361f40011b242c492c2118184cc44;p=oweals%2Fmusl.git avoid using pthread cleanup push/pop in stdio when not needed unfortunately in dynamic-linked programs, these macros cause pthread_self to be initialized, which costs a couple syscalls, and (much worse) would necessarily fail, crash, and burn on ancient (2.4 and earlier) kernels where setting up a thread pointer does not work. i'd like to do this in a more generic way that avoids all use of cleanup push/pop before pthread_self has been successfully called and avoids ugly if/else constructs like the one in this commit, but for now, this will suffice. --- diff --git a/src/stdio/__stdio_read.c b/src/stdio/__stdio_read.c index ee17a576..c99ca9a9 100644 --- a/src/stdio/__stdio_read.c +++ b/src/stdio/__stdio_read.c @@ -15,9 +15,13 @@ size_t __stdio_read(FILE *f, unsigned char *buf, size_t len) }; ssize_t cnt; - pthread_cleanup_push(cleanup, f); - cnt = syscall_cp(SYS_readv, f->fd, iov, 2); - pthread_cleanup_pop(0); + if (libc.main_thread) { + pthread_cleanup_push(cleanup, f); + cnt = syscall_cp(SYS_readv, f->fd, iov, 2); + pthread_cleanup_pop(0); + } else { + cnt = syscall(SYS_readv, f->fd, iov, 2); + } if (cnt <= 0) { f->flags |= F_EOF ^ ((F_ERR^F_EOF) & cnt); f->rpos = f->rend = 0; diff --git a/src/stdio/__stdio_write.c b/src/stdio/__stdio_write.c index da45673f..cef7bbdc 100644 --- a/src/stdio/__stdio_write.c +++ b/src/stdio/__stdio_write.c @@ -18,9 +18,13 @@ size_t __stdio_write(FILE *f, const unsigned char *buf, size_t len) int iovcnt = 2; ssize_t cnt; for (;;) { - pthread_cleanup_push(cleanup, f); - cnt = syscall_cp(SYS_writev, f->fd, iov, iovcnt); - pthread_cleanup_pop(0); + if (libc.main_thread) { + pthread_cleanup_push(cleanup, f); + cnt = syscall_cp(SYS_writev, f->fd, iov, iovcnt); + pthread_cleanup_pop(0); + } else { + cnt = syscall(SYS_writev, f->fd, iov, iovcnt); + } if (cnt == rem) { f->wend = f->buf + f->buf_size; f->wpos = f->wbase = f->buf;