m68k: sanitize copy_thread(), fork/vfork/clone wrappers, switch to generic fork/vfork (20ecc91c) · Commits · EulixOS / Software / Kernel

arch/m68k/include/asm/unistd.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,8 @@
		#define __ARCH_WANT_SYS_RT_SIGACTION
		#define __ARCH_WANT_SYS_RT_SIGSUSPEND
		#define __ARCH_WANT_SYS_EXECVE
		#define __ARCH_WANT_SYS_FORK
		#define __ARCH_WANT_SYS_VFORK

		/*
		* "Conditional" syscalls

arch/m68k/kernel/entry.S

+9 −14

Original line number	Diff line number	Diff line
		@@ -44,34 +44,29 @@

		.globl system_call, buserr, trap, resume
		.globl sys_call_table
		.globl sys_fork, sys_clone, sys_vfork
		.globl __sys_fork, __sys_clone, __sys_vfork
		.globl ret_from_interrupt, bad_interrupt
		.globl auto_irqhandler_fixup
		.globl user_irqvec_fixup

		.text
		ENTRY(sys_fork)
		ENTRY(__sys_fork)
		SAVE_SWITCH_STACK
		pea %sp@(SWITCH_STACK_SIZE)
		jbsr m68k_fork
		addql #4,%sp
		RESTORE_SWITCH_STACK
		jbsr sys_fork
		lea %sp@(24),%sp
		rts

		ENTRY(sys_clone)
		ENTRY(__sys_clone)
		SAVE_SWITCH_STACK
		pea %sp@(SWITCH_STACK_SIZE)
		jbsr m68k_clone
		addql #4,%sp
		RESTORE_SWITCH_STACK
		lea %sp@(28),%sp
		rts

		ENTRY(sys_vfork)
		ENTRY(__sys_vfork)
		SAVE_SWITCH_STACK
		pea %sp@(SWITCH_STACK_SIZE)
		jbsr m68k_vfork
		addql #4,%sp
		RESTORE_SWITCH_STACK
		jbsr sys_vfork
		lea %sp@(24),%sp
		rts

		ENTRY(sys_sigreturn)

arch/m68k/kernel/process.c

+32 −54

Original line number	Diff line number	Diff line
		@@ -136,57 +136,36 @@ void flush_thread(void)
		}

		/*
		* "m68k_fork()".. By the time we get here, the
		* non-volatile registers have also been saved on the
		* stack. We do some ugly pointer stuff here.. (see
		* also copy_thread)
		* Why not generic sys_clone, you ask? m68k passes all arguments on stack.
		* And we need all registers saved, which means a bunch of stuff pushed
		* on top of pt_regs, which means that sys_clone() arguments would be
		* buried. We could, of course, copy them, but it's too costly for no
		* good reason - generic clone() would have to copy them again for
		* do_fork() anyway. So in this case it's actually better to pass pt_regs *
		* and extract arguments for do_fork() from there. Eventually we might
		* go for calling do_fork() directly from the wrapper, but only after we
		* are finished with do_fork() prototype conversion.
		*/

		asmlinkage int m68k_fork(struct pt_regs *regs)
		{
		#ifdef CONFIG_MMU
		return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
		#else
		return -EINVAL;
		#endif
		}

		asmlinkage int m68k_vfork(struct pt_regs *regs)
		{
		return do_fork(CLONE_VFORK \| CLONE_VM \| SIGCHLD, rdusp(), regs, 0,
		NULL, NULL);
		}

		asmlinkage int m68k_clone(struct pt_regs *regs)
		{
		unsigned long clone_flags;
		unsigned long newsp;
		int __user parent_tidptr, child_tidptr;

		/* syscall2 puts clone_flags in d1 and usp in d2 */
		clone_flags = regs->d1;
		newsp = regs->d2;
		parent_tidptr = (int __user *)regs->d3;
		child_tidptr = (int __user *)regs->d4;
		if (!newsp)
		newsp = rdusp();
		return do_fork(clone_flags, newsp, regs, 0,
		parent_tidptr, child_tidptr);
		/* regs will be equal to current_pt_regs() */
		return do_fork(regs->d1, regs->d2, regs, 0,
		(int __user )regs->d3, (int __user )regs->d4);
		}

		int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long arg,
		struct task_struct * p, struct pt_regs * regs)
		struct task_struct * p, struct pt_regs * unused)
		{
		struct pt_regs * childregs;
		struct switch_stack *childstack;
		struct fork_frame {
		struct switch_stack sw;
		struct pt_regs regs;
		} *frame;

		childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
		childstack = ((struct switch_stack *) childregs) - 1;
		frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;

		p->thread.usp = usp;
		p->thread.ksp = (unsigned long)childstack;
		p->thread.esp0 = (unsigned long)childregs;
		p->thread.ksp = (unsigned long)frame;
		p->thread.esp0 = (unsigned long)&frame->regs;

		/*
		* Must save the current SFC/DFC value, NOT the value when
		@@ -194,25 +173,24 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
		*/
		p->thread.fs = get_fs().seg;

		if (unlikely(!regs)) {
		if (unlikely(p->flags & PF_KTHREAD)) {
		/* kernel thread */
		memset(childstack, 0,
		sizeof(struct switch_stack) + sizeof(struct pt_regs));
		childregs->sr = PS_S;
		childstack->a3 = usp; /* function */
		childstack->d7 = arg;
		childstack->retpc = (unsigned long)ret_from_kernel_thread;
		memset(frame, 0, sizeof(struct fork_frame));
		frame->regs.sr = PS_S;
		frame->sw.a3 = usp; /* function */
		frame->sw.d7 = arg;
		frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
		p->thread.usp = 0;
		return 0;
		}
		childregs = regs;
		childregs->d0 = 0;

		childstack = ((struct switch_stack ) regs)[-1];
		childstack->retpc = (unsigned long)ret_from_fork;
		memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
		sizeof(struct fork_frame));
		frame->regs.d0 = 0;
		frame->sw.retpc = (unsigned long)ret_from_fork;
		p->thread.usp = usp ?: rdusp();

		if (clone_flags & CLONE_SETTLS)
		task_thread_info(p)->tp_value = regs->d5;
		task_thread_info(p)->tp_value = frame->regs.d5;

		#ifdef CONFIG_FPU
		if (!FPU_IS_EMU) {

arch/m68k/kernel/syscalltable.S

+3 −3

Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@ ALIGN
		ENTRY(sys_call_table)
		.long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */
		.long sys_exit
		.long sys_fork
		.long __sys_fork
		.long sys_read
		.long sys_write
		.long sys_open /* 5 */
		@@ -140,7 +140,7 @@ ENTRY(sys_call_table)
		.long sys_ipc
		.long sys_fsync
		.long sys_sigreturn
		.long sys_clone /* 120 */
		.long __sys_clone /* 120 */
		.long sys_setdomainname
		.long sys_newuname
		.long sys_cacheflush /* modify_ldt for i386 */
		@@ -210,7 +210,7 @@ ENTRY(sys_call_table)
		.long sys_sendfile
		.long sys_ni_syscall /* streams1 */
		.long sys_ni_syscall /* streams2 */
		.long sys_vfork /* 190 */
		.long __sys_vfork /* 190 */
		.long sys_getrlimit
		.long sys_mmap2
		.long sys_truncate64