![David Howells](/assets/img/avatar_default.png)
Make do_execve() take a const filename pointer so that kernel_execve() compiles correctly on ARM: arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type This also requires the argv and envp arguments to be consted twice, once for the pointer array and once for the strings the array points to. This is because do_execve() passes a pointer to the filename (now const) to copy_strings_kernel(). A simpler alternative would be to cast the filename pointer in do_execve() when it's passed to copy_strings_kernel(). do_execve() may not change any of the strings it is passed as part of the argv or envp lists as they are some of them in .rodata, so marking these strings as const should be fine. Further kernel_execve() and sys_execve() need to be changed to match. This has been test built on x86_64, frv, arm and mips. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
407 lines
11 KiB
C
407 lines
11 KiB
C
/*
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* PARISC Architecture-dependent parts of process handling
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* based on the work for i386
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*
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* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
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* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
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* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
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* Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org>
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* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
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* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
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* Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com>
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* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
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* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
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* Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
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* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
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* Copyright (C) 2001-2007 Helge Deller <deller at parisc-linux.org>
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* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <stdarg.h>
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#include <linux/elf.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/kallsyms.h>
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#include <linux/uaccess.h>
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#include <asm/io.h>
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#include <asm/asm-offsets.h>
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#include <asm/pdc.h>
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#include <asm/pdc_chassis.h>
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#include <asm/pgalloc.h>
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#include <asm/unwind.h>
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#include <asm/sections.h>
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/*
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* The idle thread. There's no useful work to be
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* done, so just try to conserve power and have a
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* low exit latency (ie sit in a loop waiting for
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* somebody to say that they'd like to reschedule)
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*/
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void cpu_idle(void)
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{
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set_thread_flag(TIF_POLLING_NRFLAG);
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/* endless idle loop with no priority at all */
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while (1) {
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while (!need_resched())
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barrier();
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preempt_enable_no_resched();
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schedule();
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preempt_disable();
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check_pgt_cache();
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}
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}
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#define COMMAND_GLOBAL F_EXTEND(0xfffe0030)
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#define CMD_RESET 5 /* reset any module */
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/*
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** The Wright Brothers and Gecko systems have a H/W problem
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** (Lasi...'nuf said) may cause a broadcast reset to lockup
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** the system. An HVERSION dependent PDC call was developed
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** to perform a "safe", platform specific broadcast reset instead
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** of kludging up all the code.
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**
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** Older machines which do not implement PDC_BROADCAST_RESET will
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** return (with an error) and the regular broadcast reset can be
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** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET
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** the PDC call will not return (the system will be reset).
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*/
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void machine_restart(char *cmd)
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{
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#ifdef FASTBOOT_SELFTEST_SUPPORT
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/*
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** If user has modified the Firmware Selftest Bitmap,
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** run the tests specified in the bitmap after the
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** system is rebooted w/PDC_DO_RESET.
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**
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** ftc_bitmap = 0x1AUL "Skip destructive memory tests"
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**
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** Using "directed resets" at each processor with the MEM_TOC
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** vector cleared will also avoid running destructive
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** memory self tests. (Not implemented yet)
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*/
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if (ftc_bitmap) {
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pdc_do_firm_test_reset(ftc_bitmap);
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}
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#endif
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/* set up a new led state on systems shipped with a LED State panel */
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pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
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/* "Normal" system reset */
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pdc_do_reset();
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/* Nope...box should reset with just CMD_RESET now */
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gsc_writel(CMD_RESET, COMMAND_GLOBAL);
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/* Wait for RESET to lay us to rest. */
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while (1) ;
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}
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void machine_halt(void)
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{
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/*
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** The LED/ChassisCodes are updated by the led_halt()
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** function, called by the reboot notifier chain.
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*/
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}
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void (*chassis_power_off)(void);
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/*
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* This routine is called from sys_reboot to actually turn off the
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* machine
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*/
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void machine_power_off(void)
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{
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/* If there is a registered power off handler, call it. */
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if (chassis_power_off)
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chassis_power_off();
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/* Put the soft power button back under hardware control.
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* If the user had already pressed the power button, the
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* following call will immediately power off. */
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pdc_soft_power_button(0);
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pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
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/* It seems we have no way to power the system off via
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* software. The user has to press the button himself. */
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printk(KERN_EMERG "System shut down completed.\n"
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"Please power this system off now.");
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}
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void (*pm_power_off)(void) = machine_power_off;
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EXPORT_SYMBOL(pm_power_off);
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/*
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* Create a kernel thread
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*/
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extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
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pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
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{
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/*
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* FIXME: Once we are sure we don't need any debug here,
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* kernel_thread can become a #define.
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*/
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return __kernel_thread(fn, arg, flags);
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}
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EXPORT_SYMBOL(kernel_thread);
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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}
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void flush_thread(void)
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{
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/* Only needs to handle fpu stuff or perf monitors.
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** REVISIT: several arches implement a "lazy fpu state".
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*/
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set_fs(USER_DS);
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}
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void release_thread(struct task_struct *dead_task)
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{
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}
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/*
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* Fill in the FPU structure for a core dump.
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*/
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int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)
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{
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if (regs == NULL)
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return 0;
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memcpy(r, regs->fr, sizeof *r);
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return 1;
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}
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int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
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{
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memcpy(r, tsk->thread.regs.fr, sizeof(*r));
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return 1;
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}
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/* Note that "fork()" is implemented in terms of clone, with
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parameters (SIGCHLD, regs->gr[30], regs). */
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int
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sys_clone(unsigned long clone_flags, unsigned long usp,
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struct pt_regs *regs)
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{
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/* Arugments from userspace are:
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r26 = Clone flags.
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r25 = Child stack.
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r24 = parent_tidptr.
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r23 = Is the TLS storage descriptor
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r22 = child_tidptr
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However, these last 3 args are only examined
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if the proper flags are set. */
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int __user *parent_tidptr = (int __user *)regs->gr[24];
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int __user *child_tidptr = (int __user *)regs->gr[22];
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/* usp must be word aligned. This also prevents users from
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* passing in the value 1 (which is the signal for a special
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* return for a kernel thread) */
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usp = ALIGN(usp, 4);
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/* A zero value for usp means use the current stack */
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if (usp == 0)
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usp = regs->gr[30];
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return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr);
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}
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int
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sys_vfork(struct pt_regs *regs)
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{
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL);
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}
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int
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copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long unused, /* in ia64 this is "user_stack_size" */
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struct task_struct * p, struct pt_regs * pregs)
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{
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struct pt_regs * cregs = &(p->thread.regs);
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void *stack = task_stack_page(p);
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/* We have to use void * instead of a function pointer, because
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* function pointers aren't a pointer to the function on 64-bit.
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* Make them const so the compiler knows they live in .text */
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extern void * const ret_from_kernel_thread;
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extern void * const child_return;
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#ifdef CONFIG_HPUX
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extern void * const hpux_child_return;
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#endif
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*cregs = *pregs;
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/* Set the return value for the child. Note that this is not
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actually restored by the syscall exit path, but we put it
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here for consistency in case of signals. */
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cregs->gr[28] = 0; /* child */
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/*
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* We need to differentiate between a user fork and a
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* kernel fork. We can't use user_mode, because the
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* the syscall path doesn't save iaoq. Right now
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* We rely on the fact that kernel_thread passes
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* in zero for usp.
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*/
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if (usp == 1) {
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/* kernel thread */
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cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
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/* Must exit via ret_from_kernel_thread in order
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* to call schedule_tail()
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*/
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cregs->kpc = (unsigned long) &ret_from_kernel_thread;
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/*
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* Copy function and argument to be called from
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* ret_from_kernel_thread.
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*/
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#ifdef CONFIG_64BIT
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cregs->gr[27] = pregs->gr[27];
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#endif
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cregs->gr[26] = pregs->gr[26];
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cregs->gr[25] = pregs->gr[25];
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} else {
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/* user thread */
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/*
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* Note that the fork wrappers are responsible
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* for setting gr[21].
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*/
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/* Use same stack depth as parent */
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cregs->ksp = (unsigned long)stack
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+ (pregs->gr[21] & (THREAD_SIZE - 1));
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cregs->gr[30] = usp;
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if (p->personality == PER_HPUX) {
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#ifdef CONFIG_HPUX
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cregs->kpc = (unsigned long) &hpux_child_return;
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#else
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BUG();
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#endif
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} else {
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cregs->kpc = (unsigned long) &child_return;
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}
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/* Setup thread TLS area from the 4th parameter in clone */
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if (clone_flags & CLONE_SETTLS)
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cregs->cr27 = pregs->gr[23];
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}
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return 0;
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}
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unsigned long thread_saved_pc(struct task_struct *t)
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{
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return t->thread.regs.kpc;
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}
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/*
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* sys_execve() executes a new program.
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*/
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asmlinkage int sys_execve(struct pt_regs *regs)
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{
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int error;
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char *filename;
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filename = getname((const char __user *) regs->gr[26]);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename,
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(const char __user *const __user *) regs->gr[25],
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(const char __user *const __user *) regs->gr[24],
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regs);
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putname(filename);
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out:
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return error;
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}
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extern int __execve(const char *filename,
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const char *const argv[],
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const char *const envp[], struct task_struct *task);
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int kernel_execve(const char *filename,
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const char *const argv[],
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const char *const envp[])
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{
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return __execve(filename, argv, envp, current);
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}
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unsigned long
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get_wchan(struct task_struct *p)
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{
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struct unwind_frame_info info;
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unsigned long ip;
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int count = 0;
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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/*
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* These bracket the sleeping functions..
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*/
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unwind_frame_init_from_blocked_task(&info, p);
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do {
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if (unwind_once(&info) < 0)
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return 0;
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ip = info.ip;
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if (!in_sched_functions(ip))
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return ip;
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} while (count++ < 16);
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return 0;
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}
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#ifdef CONFIG_64BIT
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void *dereference_function_descriptor(void *ptr)
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{
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Elf64_Fdesc *desc = ptr;
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void *p;
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if (!probe_kernel_address(&desc->addr, p))
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ptr = p;
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return ptr;
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}
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#endif
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