11 files changed, 118 insertions, 7 deletions

diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index 2c11abb5a406..af69cdbdd50e 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -95,6 +95,7 @@ void output_thread_info_defines(void)
         offset("#define TI_PRE_COUNT       ", struct thread_info, preempt_count);
         offset("#define TI_ADDR_LIMIT      ", struct thread_info, addr_limit);
         offset("#define TI_RESTART_BLOCK   ", struct thread_info, restart_block);
+        offset("#define TI_TP_VALUE        ", struct thread_info, tp_value);
         constant("#define _THREAD_SIZE_ORDER ", THREAD_SIZE_ORDER);
         constant("#define _THREAD_SIZE       ", THREAD_SIZE);
         constant("#define _THREAD_MASK       ", THREAD_MASK);
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index e8e886dd52d6..330cf84d21fe 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -1468,3 +1468,30 @@ sysn32_rt_sigtimedwait(const sigset_t __user *uthese,
         }
         return sys_rt_sigtimedwait(uthese, uinfo, uts, sigsetsize);
 }
+
+save_static_function(sys32_clone);
+__attribute_used__ noinline static int
+_sys32_clone(nabi_no_regargs struct pt_regs regs)
+{
+        unsigned long clone_flags;
+        unsigned long newsp;
+        int __user *parent_tidptr, *child_tidptr;
+
+        clone_flags = regs.regs[4];
+        newsp = regs.regs[5];
+        if (!newsp)
+                newsp = regs.regs[29];
+        parent_tidptr = (int *) regs.regs[6];
+
+        /* Use __dummy4 instead of getting it off the stack, so that
+           syscall() works.  */
+        child_tidptr = (int __user *) __dummy4;
+        return do_fork(clone_flags, newsp, &regs, 0,
+                       parent_tidptr, child_tidptr);
+}
+
+extern asmlinkage void sys_set_thread_area(u32 addr);
+asmlinkage void sys32_set_thread_area(u32 addr)
+{
+        sys_set_thread_area(AA(addr));
+}
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 2b7a44deb856..368526af5f5e 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -89,6 +89,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
         struct thread_info *ti = p->thread_info;
         struct pt_regs *childregs;
         long childksp;
+        p->set_child_tid = p->clear_child_tid = NULL;
 
         childksp = (unsigned long)ti + THREAD_SIZE - 32;
 
@@ -134,6 +135,9 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
         childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
         clear_tsk_thread_flag(p, TIF_USEDFPU);
 
+        if (clone_flags & CLONE_SETTLS)
+                ti->tp_value = regs->regs[7];
+
         return 0;
 }
 
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 2c7fc7472fb2..649c90dee38e 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -289,6 +289,11 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
                 ret = ptrace_detach(child, data);
                 break;
 
+        case PTRACE_GET_THREAD_AREA:
+                ret = put_user(child->thread_info->tp_value,
+                                (unsigned long __user *) data);
+                break;
+
         default:
                 ret = ptrace_request(child, request, addr, data);
                 break;
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index a8a72c9a1cca..eb446e525908 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -268,6 +268,11 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                 wake_up_process(child);
                 break;
 
+        case PTRACE_GET_THREAD_AREA:
+                ret = put_user(child->thread_info->tp_value,
+                                (unsigned int __user *) (unsigned long) data);
+                break;
+
         case PTRACE_DETACH: /* detach a process that was attached. */
                 ret = ptrace_detach(child, data);
                 break;
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index 9c4bb917d476..6fa1112512c8 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -623,6 +623,7 @@ einval:	li	v0, -EINVAL
         sys     sys_add_key             5
         sys     sys_request_key         4
         sys     sys_keyctl              5
+        sys     sys_set_thread_area     1
 
         .endm
 
diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S
index ffb22a2068bf..d11f99b0ae53 100644
--- a/arch/mips/kernel/scall64-64.S
+++ b/arch/mips/kernel/scall64-64.S
@@ -449,3 +449,4 @@ sys_call_table:
         PTR     sys_add_key
         PTR     sys_request_key                 /* 5240 */
         PTR     sys_keyctl
+        PTR     sys_set_thread_area
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index d912218259e5..ce030412efbe 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -363,3 +363,4 @@ EXPORT(sysn32_call_table)
         PTR     sys_add_key
         PTR     sys_request_key
         PTR     sys_keyctl                      /* 6245 */
+        PTR     sys_set_thread_area
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 1017176bdce9..f49182ea73f8 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -322,7 +322,7 @@ sys_call_table:
         PTR     sys32_ipc
         PTR     sys_fsync
         PTR     sys32_sigreturn
-        PTR     sys_clone                       /* 4120 */
+        PTR     sys32_clone                     /* 4120 */
         PTR     sys_setdomainname
         PTR     sys32_newuname
         PTR     sys_ni_syscall                  /* sys_modify_ldt */
@@ -485,4 +485,5 @@ sys_call_table:
         PTR     sys_add_key                     /* 4280 */
         PTR     sys_request_key
         PTR     sys_keyctl
+        PTR     sys_set_thread_area
         .size   sys_call_table,.-sys_call_table
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 8fde242596f9..ee98eeb65e85 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -7,6 +7,7 @@
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  * Copyright (C) 2001 MIPS Technologies, Inc.
  */
+#include <linux/config.h>
 #include <linux/a.out.h>
 #include <linux/errno.h>
 #include <linux/linkage.h>
@@ -176,14 +177,28 @@ _sys_clone(nabi_no_regargs struct pt_regs regs)
 {
         unsigned long clone_flags;
         unsigned long newsp;
-        int *parent_tidptr, *child_tidptr;
+        int __user *parent_tidptr, *child_tidptr;
 
         clone_flags = regs.regs[4];
         newsp = regs.regs[5];
         if (!newsp)
                 newsp = regs.regs[29];
-        parent_tidptr = (int *) regs.regs[6];
-        child_tidptr = (int *) regs.regs[7];
+        parent_tidptr = (int __user *) regs.regs[6];
+#ifdef CONFIG_32BIT
+        /* We need to fetch the fifth argument off the stack.  */
+        child_tidptr = NULL;
+        if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
+                int __user *__user *usp = (int __user *__user *) regs.regs[29];
+                if (regs.regs[2] == __NR_syscall) {
+                        if (get_user (child_tidptr, &usp[5]))
+                                return -EFAULT;
+                }
+                else if (get_user (child_tidptr, &usp[4]))
+                        return -EFAULT;
+        }
+#else
+        child_tidptr = (int __user *) regs.regs[8];
+#endif
         return do_fork(clone_flags, newsp, &regs, 0,
                        parent_tidptr, child_tidptr);
 }
@@ -245,6 +260,16 @@ asmlinkage int sys_olduname(struct oldold_utsname * name)
         return error;
 }
 
+void sys_set_thread_area(unsigned long addr)
+{
+        struct thread_info *ti = current->thread_info;
+
+        ti->tp_value = addr;
+
+        /* If some future MIPS implementation has this register in hardware,
+         * we will need to update it here (and in context switches).  */
+}
+
 asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
 {
         int     tmp, len;
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 94d9141c04c1..15fed0202154 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -360,6 +360,10 @@ static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode)
 #define OFFSET 0x0000ffff
 #define LL     0xc0000000
 #define SC     0xe0000000
+#define SPEC3  0x7c000000
+#define RD     0x0000f800
+#define FUNC   0x0000003f
+#define RDHWR  0x0000003b
 
 /*
  * The ll_bit is cleared by r*_switch.S
@@ -495,6 +499,37 @@ static inline int simulate_llsc(struct pt_regs *regs)
         return -EFAULT;                 /* Strange things going on ... */
 }
 
+/*
+ * Simulate trapping 'rdhwr' instructions to provide user accessible
+ * registers not implemented in hardware.  The only current use of this
+ * is the thread area pointer.
+ */
+static inline int simulate_rdhwr(struct pt_regs *regs)
+{
+        struct thread_info *ti = current->thread_info;
+        unsigned int opcode;
+
+        if (unlikely(get_insn_opcode(regs, &opcode)))
+                return -EFAULT;
+
+        if (unlikely(compute_return_epc(regs)))
+                return -EFAULT;
+
+        if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
+                int rd = (opcode & RD) >> 11;
+                int rt = (opcode & RT) >> 16;
+                switch (rd) {
+                        case 29:
+                                regs->regs[rt] = ti->tp_value;
+                                break;
+                        default:
+                                return -EFAULT;
+                }
+        }
+
+        return 0;
+}
+
 asmlinkage void do_ov(struct pt_regs *regs)
 {
         siginfo_t info;
@@ -641,6 +676,9 @@ asmlinkage void do_ri(struct pt_regs *regs)
                 if (!simulate_llsc(regs))
                         return;
 
+        if (!simulate_rdhwr(regs))
+                return;
+
         force_sig(SIGILL, current);
 }
 
@@ -654,11 +692,13 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 
         switch (cpid) {
         case 0:
-                if (cpu_has_llsc)
-                        break;
+                if (!cpu_has_llsc)
+                        if (!simulate_llsc(regs))
+                                return;
 
-                if (!simulate_llsc(regs))
+                if (!simulate_rdhwr(regs))
                         return;
+
                 break;
 
         case 1: