linux_dsm_epyc7002/arch/mips/kernel/syscall.c
Al Viro f0a955f4ee mips: sanitize __access_ok()
for one thing, the last argument is always __access_mask and had been such
since 2.4.0-test3pre8; for another, it can bloody well be a static inline -
-O2 or -Os, __builtin_constant_p() propagates through static inline calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-06 02:08:06 -04:00

240 lines
5.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
*/
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/unistd.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/compiler.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/elf.h>
#include <linux/sched/task_stack.h>
#include <asm/asm.h>
#include <asm/branch.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#include <asm/signal.h>
#include <asm/sim.h>
#include <asm/shmparam.h>
#include <asm/sysmips.h>
#include <asm/switch_to.h>
/*
* For historic reasons the pipe(2) syscall on MIPS has an unusual calling
* convention. It returns results in registers $v0 / $v1 which means there
* is no need for it to do verify the validity of a userspace pointer
* argument. Historically that used to be expensive in Linux. These days
* the performance advantage is negligible.
*/
asmlinkage int sysm_pipe(void)
{
int fd[2];
int error = do_pipe_flags(fd, 0);
if (error)
return error;
current_pt_regs()->regs[3] = fd[1];
return fd[0];
}
SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long,
fd, off_t, offset)
{
if (offset & ~PAGE_MASK)
return -EINVAL;
return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
}
SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags, unsigned long, fd,
unsigned long, pgoff)
{
if (pgoff & (~PAGE_MASK >> 12))
return -EINVAL;
return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
}
save_static_function(sys_fork);
save_static_function(sys_clone);
SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
{
struct thread_info *ti = task_thread_info(current);
ti->tp_value = addr;
if (cpu_has_userlocal)
write_c0_userlocal(addr);
return 0;
}
static inline int mips_atomic_set(unsigned long addr, unsigned long new)
{
unsigned long old, tmp;
struct pt_regs *regs;
unsigned int err;
if (unlikely(addr & 3))
return -EINVAL;
if (unlikely(!access_ok(VERIFY_WRITE, (const void __user *)addr, 4)))
return -EINVAL;
if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__ (
" .set arch=r4000 \n"
" li %[err], 0 \n"
"1: ll %[old], (%[addr]) \n"
" move %[tmp], %[new] \n"
"2: sc %[tmp], (%[addr]) \n"
" beqzl %[tmp], 1b \n"
"3: \n"
" .insn \n"
" .section .fixup,\"ax\" \n"
"4: li %[err], %[efault] \n"
" j 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "STR(PTR)" 1b, 4b \n"
" "STR(PTR)" 2b, 4b \n"
" .previous \n"
" .set mips0 \n"
: [old] "=&r" (old),
[err] "=&r" (err),
[tmp] "=&r" (tmp)
: [addr] "r" (addr),
[new] "r" (new),
[efault] "i" (-EFAULT)
: "memory");
} else if (cpu_has_llsc) {
__asm__ __volatile__ (
" .set "MIPS_ISA_ARCH_LEVEL" \n"
" li %[err], 0 \n"
"1: ll %[old], (%[addr]) \n"
" move %[tmp], %[new] \n"
"2: sc %[tmp], (%[addr]) \n"
" bnez %[tmp], 4f \n"
"3: \n"
" .insn \n"
" .subsection 2 \n"
"4: b 1b \n"
" .previous \n"
" \n"
" .section .fixup,\"ax\" \n"
"5: li %[err], %[efault] \n"
" j 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "STR(PTR)" 1b, 5b \n"
" "STR(PTR)" 2b, 5b \n"
" .previous \n"
" .set mips0 \n"
: [old] "=&r" (old),
[err] "=&r" (err),
[tmp] "=&r" (tmp)
: [addr] "r" (addr),
[new] "r" (new),
[efault] "i" (-EFAULT)
: "memory");
} else {
do {
preempt_disable();
ll_bit = 1;
ll_task = current;
preempt_enable();
err = __get_user(old, (unsigned int *) addr);
err |= __put_user(new, (unsigned int *) addr);
if (err)
break;
rmb();
} while (!ll_bit);
}
if (unlikely(err))
return err;
regs = current_pt_regs();
regs->regs[2] = old;
regs->regs[7] = 0; /* No error */
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
" move $29, %0 \n"
" j syscall_exit \n"
: /* no outputs */
: "r" (regs));
/* unreached. Honestly. */
unreachable();
}
SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
{
switch (cmd) {
case MIPS_ATOMIC_SET:
return mips_atomic_set(arg1, arg2);
case MIPS_FIXADE:
if (arg1 & ~3)
return -EINVAL;
if (arg1 & 1)
set_thread_flag(TIF_FIXADE);
else
clear_thread_flag(TIF_FIXADE);
if (arg1 & 2)
set_thread_flag(TIF_LOGADE);
else
clear_thread_flag(TIF_LOGADE);
return 0;
case FLUSH_CACHE:
__flush_cache_all();
return 0;
}
return -EINVAL;
}
/*
* No implemented yet ...
*/
SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
{
return -ENOSYS;
}
/*
* If we ever come here the user sp is bad. Zap the process right away.
* Due to the bad stack signaling wouldn't work.
*/
asmlinkage void bad_stack(void)
{
do_exit(SIGSEGV);
}