From 70fd6b3b230f58782a196b1075513a24f2376077 Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Wed, 17 May 2023 22:14:34 +0300 Subject: [PATCH] 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 be6d002ca277ffc90058d382396150cb0e785b9c "hurd: Set up the basic tree for x86_64-gnu" Signed-off-by: Sergey Bugaev Message-Id: <20230517191436.73636-9-bugaevc@gmail.com> --- .../mach/hurd/{x86 => i386}/htl/pt-setup.c | 2 +- sysdeps/mach/hurd/x86_64/htl/pt-setup.c | 93 +++++++++++++++++++ 2 files changed, 94 insertions(+), 1 deletion(-) rename sysdeps/mach/hurd/{x86 => i386}/htl/pt-setup.c (98%) create mode 100644 sysdeps/mach/hurd/x86_64/htl/pt-setup.c diff --git a/sysdeps/mach/hurd/x86/htl/pt-setup.c b/sysdeps/mach/hurd/i386/htl/pt-setup.c similarity index 98% rename from sysdeps/mach/hurd/x86/htl/pt-setup.c rename to sysdeps/mach/hurd/i386/htl/pt-setup.c index 686124d70a..ba108b9611 100644 --- a/sysdeps/mach/hurd/x86/htl/pt-setup.c +++ b/sysdeps/mach/hurd/i386/htl/pt-setup.c @@ -1,4 +1,4 @@ -/* Setup thread stack. Hurd/x86 version. +/* Setup thread stack. Hurd/i386 version. Copyright (C) 2000-2023 Free Software Foundation, Inc. This file is part of the GNU C Library. diff --git a/sysdeps/mach/hurd/x86_64/htl/pt-setup.c b/sysdeps/mach/hurd/x86_64/htl/pt-setup.c new file mode 100644 index 0000000000..7dc6291261 --- /dev/null +++ b/sysdeps/mach/hurd/x86_64/htl/pt-setup.c @@ -0,0 +1,93 @@ +/* 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 + . */ + +#include +#include +#include +#include + +#include +#include + +/* 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; +}