diff options
Diffstat (limited to 'arch/mips/kernel/syscall.c')
| -rw-r--r-- | arch/mips/kernel/syscall.c | 112 |
1 files changed, 109 insertions, 3 deletions
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c index 8cf38464404..3fe1fcfa2e7 100644 --- a/arch/mips/kernel/syscall.c +++ b/arch/mips/kernel/syscall.c @@ -28,7 +28,9 @@ #include <linux/compiler.h> #include <linux/module.h> #include <linux/ipc.h> +#include <linux/uaccess.h> +#include <asm/asm.h> #include <asm/branch.h> #include <asm/cachectl.h> #include <asm/cacheflush.h> @@ -290,12 +292,116 @@ SYSCALL_DEFINE1(set_thread_area, unsigned long, addr) return 0; } -asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3) +static inline int mips_atomic_set(struct pt_regs *regs, + unsigned long addr, unsigned long new) { + unsigned long old, tmp; + unsigned int err; + + if (unlikely(addr & 3)) + return -EINVAL; + + if (unlikely(!access_ok(VERIFY_WRITE, addr, 4))) + return -EINVAL; + + if (cpu_has_llsc && R10000_LLSC_WAR) { + __asm__ __volatile__ ( + " li %[err], 0 \n" + "1: ll %[old], (%[addr]) \n" + " move %[tmp], %[new] \n" + "2: sc %[tmp], (%[addr]) \n" + " beqzl %[tmp], 1b \n" + "3: \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" + : [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__ ( + " li %[err], 0 \n" + "1: ll %[old], (%[addr]) \n" + " move %[tmp], %[new] \n" + "2: sc %[tmp], (%[addr]) \n" + " bnez %[tmp], 4f \n" + "3: \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" + : [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->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. */ + while (1); +} + +save_static_function(sys_sysmips); +static int __used noinline +_sys_sysmips(nabi_no_regargs struct pt_regs regs) +{ + long cmd, arg1, arg2, arg3; + + cmd = regs.regs[4]; + arg1 = regs.regs[5]; + arg2 = regs.regs[6]; + arg3 = regs.regs[7]; + switch (cmd) { case MIPS_ATOMIC_SET: - printk(KERN_CRIT "How did I get here?\n"); - return -EINVAL; + return mips_atomic_set(®s, arg1, arg2); case MIPS_FIXADE: if (arg1 & ~3) |