From 01f317e98f7e36b597905a7ad267ce6b59d463ee Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Wed, 17 May 2023 22:14:30 +0300 Subject: [PATCH] mach: Add __mach_setup_thread_call () This is just like mach_setup_thread (), but it's suitable for making the thread call a function correctly, as opposed to explicitly setting the thread's stack and instruction pointers to the given values. Internally, it uses MACHINE_THREAD_STATE_SETUP_CALL. Unlike mach_setup_thread (), which is exported via mach.h for the benefit of the Hurd exec server, __mach_setup_thread_call () is private to glibc for the time being. Signed-off-by: Sergey Bugaev Message-Id: <20230517191436.73636-5-bugaevc@gmail.com> --- mach/mach.h | 6 +++++- mach/setup-thread.c | 52 +++++++++++++++++++++++++++++++++++++--------------- mach/setup-thread.h | 32 ++++++++++++++++++++++++++++++++ 3 files changed, 74 insertions(+), 16 deletions(-) create mode 100644 mach/setup-thread.h diff --git a/mach/mach.h b/mach/mach.h index d115f5a..348f019 100644 --- a/mach/mach.h +++ b/mach/mach.h @@ -88,7 +88,11 @@ extern FILE *mach_open_devstream (mach_port_t device_port, const char *mode); If STACK_BASE is not null it is filled in with the chosen stack base. If STACK_SIZE is not null it is filled in with the chosen stack size. Regardless, an extra page of red zone is allocated off the end; this - is not included in *STACK_SIZE. */ + is not included in *STACK_SIZE. + + Mote: this function is unsuitable for setting up the thread to call a + function at PC, since the architecture ABI may impose additional + requirements beyond setting PC and stack. */ kern_return_t __mach_setup_thread (task_t task, thread_t thread, void *pc, vm_address_t *stack_base, vm_size_t *stack_size); diff --git a/mach/setup-thread.c b/mach/setup-thread.c index ae24a14..0e14978 100644 --- a/mach/setup-thread.c +++ b/mach/setup-thread.c @@ -16,6 +16,7 @@ . */ #include +#include #include #include #include @@ -24,17 +25,10 @@ #define STACK_SIZE (16 * 1024 * 1024) /* 16MB, arbitrary. */ -/* Give THREAD a stack and set it to run at PC when resumed. - If *STACK_SIZE is nonzero, that size of stack is allocated. - If *STACK_BASE is nonzero, that stack location is used. - If STACK_BASE is not null it is filled in with the chosen stack base. - If STACK_SIZE is not null it is filled in with the chosen stack size. - Regardless, an extra page of red zone is allocated off the end; this - is not included in *STACK_SIZE. */ - -kern_return_t -__mach_setup_thread (task_t task, thread_t thread, void *pc, - vm_address_t *stack_base, vm_size_t *stack_size) +static kern_return_t +mach_setup_thread_impl (task_t task, thread_t thread, int is_call, + void *pc, vm_address_t *stack_base, + vm_size_t *stack_size) { kern_return_t error; struct machine_thread_state ts; @@ -43,6 +37,8 @@ __mach_setup_thread (task_t task, thread_t thread, void *pc, vm_size_t size; int anywhere; + memset (&ts, 0, sizeof (ts)); + size = stack_size ? *stack_size ? : STACK_SIZE : STACK_SIZE; stack = stack_base ? *stack_base ? : 0 : 0; anywhere = !stack_base || !*stack_base; @@ -54,21 +50,25 @@ __mach_setup_thread (task_t task, thread_t thread, void *pc, if (stack_size) *stack_size = size; - memset (&ts, 0, sizeof (ts)); - MACHINE_THREAD_STATE_SET_PC (&ts, pc); #ifdef STACK_GROWTH_DOWN if (stack_base) *stack_base = stack + __vm_page_size; - ts.SP = stack + __vm_page_size + size; #elif defined (STACK_GROWTH_UP) if (stack_base) *stack_base = stack; - ts.SP = stack; stack += size; #else #error stack direction unknown #endif + if (is_call) + MACHINE_THREAD_STATE_SETUP_CALL (&ts, *stack_base, size, pc); + else + { + MACHINE_THREAD_STATE_SET_PC (&ts, pc); + MACHINE_THREAD_STATE_SET_SP (&ts, *stack_base, size); + } + /* Create the red zone. */ if (error = __vm_protect (task, stack, __vm_page_size, 0, VM_PROT_NONE)) return error; @@ -77,8 +77,30 @@ __mach_setup_thread (task_t task, thread_t thread, void *pc, (natural_t *) &ts, tssize); } +/* Give THREAD a stack and set it to run at PC when resumed. + If *STACK_SIZE is nonzero, that size of stack is allocated. + If *STACK_BASE is nonzero, that stack location is used. + If STACK_BASE is not null it is filled in with the chosen stack base. + If STACK_SIZE is not null it is filled in with the chosen stack size. + Regardless, an extra page of red zone is allocated off the end; this + is not included in *STACK_SIZE. */ + +kern_return_t +__mach_setup_thread (task_t task, thread_t thread, void *pc, + vm_address_t *stack_base, vm_size_t *stack_size) +{ + return mach_setup_thread_impl (task, thread, 0, pc, stack_base, stack_size); +} + weak_alias (__mach_setup_thread, mach_setup_thread) +kern_return_t +__mach_setup_thread_call (task_t task, thread_t thread, void *pc, + vm_address_t *stack_base, vm_size_t *stack_size) +{ + return mach_setup_thread_impl (task, thread, 1, pc, stack_base, stack_size); +} + /* Give THREAD a TLS area. */ kern_return_t __mach_setup_tls (thread_t thread) diff --git a/mach/setup-thread.h b/mach/setup-thread.h new file mode 100644 index 0000000..b4c94d1 --- /dev/null +++ b/mach/setup-thread.h @@ -0,0 +1,32 @@ +/* Setup a Mach thread. + Copyright (C) 1993-2023 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 + . */ + +#ifndef _MACH_SETUP_THREAD_H + +#define _MACH_SETUP_THREAD_H 1 + +#include + +/* Like mach_setup_thread (), but suitable for setting up function + calls. */ +kern_return_t __mach_setup_thread_call (task_t task, thread_t thread, + void *function, + vm_address_t *stack_base, + vm_size_t *stack_size); + +#endif /* mach/setup-thread.h */ -- 2.7.4