From 9cec82de715b3ffc625a6c67d107a3fcb26af566 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Wed, 11 Nov 2020 10:35:10 +0000 Subject: htl: Initialize later Since htl does not actually need a stack switch, we can initialize it like nptl is, avoiding all sorts of startup issues with ifunc. More precisely, htl defines __pthread_initialize_minimal instead of the elder _cthread_init_routine. We can then drop the stack switching dances. --- sysdeps/mach/hurd/i386/init-first.c | 106 ++++++++---------------------------- 1 file changed, 24 insertions(+), 82 deletions(-) (limited to 'sysdeps/mach/hurd/i386/init-first.c') diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c index 5e66602d4b..6c35dc8104 100644 --- a/sysdeps/mach/hurd/i386/init-first.c +++ b/sysdeps/mach/hurd/i386/init-first.c @@ -46,9 +46,6 @@ extern int __libc_argc attribute_hidden; extern char **__libc_argv attribute_hidden; extern char **_dl_argv; -extern void *(*_cthread_init_routine) (void) __attribute__ ((weak)); -void (*_cthread_exit_routine) (int status) __attribute__ ((__noreturn__)); - /* Things that want to be run before _hurd_init or much anything else. Importantly, these are called before anything tries to use malloc. */ DEFINE_HOOK (_hurd_preinit_hook, (void)); @@ -96,10 +93,6 @@ init1 (int argc, char *arg0, ...) ++envp; d = (void *) ++envp; - /* Initialize libpthread if linked in. */ - if (__pthread_initialize_minimal != NULL) - __pthread_initialize_minimal (); - if ((void *) d == argv[0]) /* No Hurd data block to process. */ return; @@ -145,7 +138,6 @@ init (int *data) int argc = *data; char **argv = (void *) (data + 1); char **envp = &argv[argc + 1]; - struct hurd_startup_data *d; /* Since the cthreads initialization code uses malloc, and the malloc initialization code needs to get at the environment, make @@ -154,11 +146,13 @@ init (int *data) stored. */ __environ = envp; +#ifndef SHARED + struct hurd_startup_data *d; + while (*envp) ++envp; d = (void *) ++envp; -#ifndef SHARED /* If we are the bootstrap task started by the kernel, then after the environment pointers there is no Hurd data block; the argument strings start there. */ @@ -190,79 +184,27 @@ init (int *data) __libc_setup_tls (); #endif - /* After possibly switching stacks, call `init1' (above) with the user - code as the return address, and the argument data immediately above - that on the stack. */ - - if (&_cthread_init_routine && _cthread_init_routine) - { - /* Initialize cthreads, which will allocate us a new stack to run on. */ - int *newsp = (*_cthread_init_routine) (); - struct hurd_startup_data *od; - - void switch_stacks (void); - - __libc_stack_end = newsp; - - /* Copy the argdata from the old stack to the new one. */ - newsp = memcpy (newsp - ((char *) &d[1] - (char *) data), data, - (char *) d - (char *) data); - -#ifdef SHARED - /* And readjust the dynamic linker's idea of where the argument - vector lives. */ - assert (_dl_argv == argv); - _dl_argv = (void *) (newsp + 1); -#endif - - /* Set up the Hurd startup data block immediately following - the argument and environment pointers on the new stack. */ - od = ((void *) newsp + ((char *) d - (char *) data)); - if ((void *) argv[0] == d) - /* We were started up by the kernel with arguments on the stack. - There is no Hurd startup data, so zero the block. */ - memset (od, 0, sizeof *od); - else - /* Copy the Hurd startup data block to the new stack. */ - *od = *d; - - /* Push the user code address on the top of the new stack. It will - be the return address for `init1'; we will jump there with NEWSP - as the stack pointer. */ - /* The following expression would typically be written as - ``__builtin_return_address (0)''. But, for example, GCC 4.4.6 doesn't - recognize that this read operation may alias the following write - operation, and thus is free to reorder the two, clobbering the - original return address. */ - *--newsp = *((int *) __builtin_frame_address (0) + 1); - /* GCC 4.4.6 also wants us to force loading *NEWSP already here. */ - asm volatile ("# %0" : : "X" (*newsp)); - *((void **) __builtin_frame_address (0) + 1) = &switch_stacks; - /* Force NEWSP into %eax and &init1 into %ecx, which are not restored - by function return. */ - asm volatile ("# a %0 c %1" : : "a" (newsp), "c" (&init1)); - } - else - { - int usercode; - - void call_init1 (void); - - /* The argument data is just above the stack frame we will unwind by - returning. Mutate our own return address to run the code below. */ - /* The following expression would typically be written as - ``__builtin_return_address (0)''. But, for example, GCC 4.4.6 doesn't - recognize that this read operation may alias the following write - operation, and thus is free to reorder the two, clobbering the - original return address. */ - usercode = *((int *) __builtin_frame_address (0) + 1); - /* GCC 4.4.6 also wants us to force loading USERCODE already here. */ - asm volatile ("# %0" : : "X" (usercode)); - *((void **) __builtin_frame_address (0) + 1) = &call_init1; - /* Force USERCODE into %eax and &init1 into %ecx, which are not - restored by function return. */ - asm volatile ("# a %0 c %1" : : "a" (usercode), "c" (&init1)); - } + /* Call `init1' (above) with the user code as the return address, and the + argument data immediately above that on the stack. */ + + int usercode; + + void call_init1 (void); + + /* The argument data is just above the stack frame we will unwind by + returning. Mutate our own return address to run the code below. */ + /* The following expression would typically be written as + ``__builtin_return_address (0)''. But, for example, GCC 4.4.6 doesn't + recognize that this read operation may alias the following write + operation, and thus is free to reorder the two, clobbering the + original return address. */ + usercode = *((int *) __builtin_frame_address (0) + 1); + /* GCC 4.4.6 also wants us to force loading USERCODE already here. */ + asm volatile ("# %0" : : "X" (usercode)); + *((void **) __builtin_frame_address (0) + 1) = &call_init1; + /* Force USERCODE into %eax and &init1 into %ecx, which are not + restored by function return. */ + asm volatile ("# a %0 c %1" : : "a" (usercode), "c" (&init1)); DIAG_POP_NEEDS_COMMENT; /* -Warray-bounds. */ } -- cgit 1.4.1