hurd: Fix setting up pthreads

On x86_64, we have to pass function arguments in registers, not on the
stack. We also have to align the stack pointer in a specific way. Since
sharing the logic with i386 does not bring much benefit, split the file
back into i386- and x86_64-specific versions, and fix the x86_64 version
to set up the thread properly.

Bonus: i386 keeps doing the extra RPC inside __thread_set_pcsptp to
fetch the state of the thread before setting it; but x86_64 no lnoger
does that.

Checked on x86_64-gnu and i686-gnu.

Fixes be6d002ca2
"hurd: Set up the basic tree for x86_64-gnu"

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-9-bugaevc@gmail.com>
This commit is contained in:
Sergey Bugaev 2023-05-17 22:14:34 +03:00 committed by Samuel Thibault
parent 2f8ecb58a5
commit 70fd6b3b23
2 changed files with 94 additions and 1 deletions

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@ -1,4 +1,4 @@
/* Setup thread stack. Hurd/x86 version. /* Setup thread stack. Hurd/i386 version.
Copyright (C) 2000-2023 Free Software Foundation, Inc. Copyright (C) 2000-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.

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/* Setup thread stack. Hurd/x86_64 version.
Copyright (C) 2000-2023 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 <stdint.h>
#include <assert.h>
#include <mach.h>
#include <hurd.h>
#include <thread_state.h>
#include <pt-internal.h>
/* Set up the stack for THREAD. Return the stack pointer
for the new thread. */
static void *
stack_setup (struct __pthread *thread)
{
error_t err;
uintptr_t bottom, top;
/* Calculate the top of the new stack. */
bottom = (uintptr_t) thread->stackaddr;
top = bottom + thread->stacksize + round_page (thread->guardsize);
if (thread->guardsize)
{
err = __vm_protect (__mach_task_self (), (vm_address_t) bottom,
thread->guardsize, 0, 0);
assert_perror (err);
}
return (void *) PTR_ALIGN_DOWN_8_16 (top);
}
int
__pthread_setup (struct __pthread *thread,
void (*entry_point) (struct __pthread *, void *(*)(void *),
void *), void *(*start_routine) (void *),
void *arg)
{
error_t err;
struct i386_thread_state state;
struct i386_fsgs_base_state fsgs_state;
if (thread->kernel_thread == hurd_thread_self ())
/* Fix up the TCB for the main thread. The C library has already
installed a TCB, which we want to keep using. This TCB must not
be freed so don't register it in the thread structure. On the
other hand, it's not yet possible to reliably release a TCB.
Leave the unused one registered so that it doesn't leak. */
return 0;
thread->mcontext.pc = entry_point;
thread->mcontext.sp = stack_setup (thread);
/* Set up the state to call entry_point (thread, start_routine, arg) */
memset (&state, 0, sizeof (state));
state.ursp = (uintptr_t) thread->mcontext.sp;
state.rip = (uintptr_t) thread->mcontext.pc;
state.rdi = (uintptr_t) thread;
state.rsi = (uintptr_t) start_routine;
state.rdx = (uintptr_t) arg;
err = __thread_set_state (thread->kernel_thread, i386_THREAD_STATE,
(thread_state_t) &state,
i386_THREAD_STATE_COUNT);
assert_perror (err);
/* Set fs_base to the TCB pointer for the thread. */
memset (&fsgs_state, 0, sizeof (fsgs_state));
fsgs_state.fs_base = (uintptr_t) thread->tcb;
err = __thread_set_state (thread->kernel_thread, i386_FSGS_BASE_STATE,
(thread_state_t) &fsgs_state,
i386_FSGS_BASE_STATE_COUNT);
assert_perror (err);
return 0;
}