Here's a kernel patch to enable NPTL support. This doesn't include Maciej's
uber-fast rdhwr emulation; I believe we ought to include both the fast and
slow paths, since the slow path will handle use of other destination
registers. Changes:
- Clone takes five arguments, not four. Um, this bit is gross.
- New syscall sys_set_thread_area. Only glibc uses this.
- Emulation of the rdhwr instruction. This version is only loosely
based on the emulation on the malta branch; the major difference
is that I fixed ll/sc/rdhwr emulation in branch delay slots.
GCC 4.1 will generate rdhwr in branch delay slots in some
conditions.
- PTRACE_GET_THREAD_AREA support for GDB.
How's it look? I've just finished hopefully final tests for the
glibc bits, and will post them once this patch is resolved.
[Credit goes to Manish Lachwani at MontaVista for writing the
first draft of this patch, though he won't recognize most of this
copy :-)]
Index: linux/arch/mips/kernel/syscall.c
===================================================================
--- linux.orig/arch/mips/kernel/syscall.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/syscall.c 2005-03-15 10:30:09.000000000 -0500
@@ -176,14 +176,28 @@ _sys_clone(nabi_no_regargs struct pt_reg
{
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_MIPS32
+ /* 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, ®s, 0,
parent_tidptr, child_tidptr);
}
@@ -245,6 +259,16 @@ asmlinkage int sys_olduname(struct oldol
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;
Index: linux/arch/mips/kernel/traps.c
===================================================================
--- linux.orig/arch/mips/kernel/traps.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/traps.c 2005-03-15 10:33:48.000000000 -0500
@@ -360,6 +360,10 @@ static inline int get_insn_opcode(struct
#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
@@ -408,9 +412,10 @@ static inline void simulate_ll(struct pt
preempt_enable();
+ compute_return_epc(regs);
+
regs->regs[(opcode & RT) >> 16] = value;
- compute_return_epc(regs);
return;
sig:
@@ -446,9 +451,9 @@ static inline void simulate_sc(struct pt
preempt_disable();
if (ll_bit == 0 || ll_task != current) {
- regs->regs[reg] = 0;
preempt_enable();
compute_return_epc(regs);
+ regs->regs[reg] = 0;
return;
}
@@ -459,9 +464,8 @@ static inline void simulate_sc(struct pt
goto sig;
}
- regs->regs[reg] = 1;
-
compute_return_epc(regs);
+ regs->regs[reg] = 1;
return;
sig:
@@ -494,6 +498,37 @@ static inline int simulate_llsc(struct p
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;
@@ -640,6 +675,9 @@ asmlinkage void do_ri(struct pt_regs *re
if (!simulate_llsc(regs))
return;
+ if (!simulate_rdhwr(regs))
+ return;
+
force_sig(SIGILL, current);
}
@@ -653,11 +691,13 @@ asmlinkage void do_cpu(struct pt_regs *r
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:
Index: linux/arch/mips/kernel/process.c
===================================================================
--- linux.orig/arch/mips/kernel/process.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/process.c 2005-03-16 09:04:04.049856461 -0500
@@ -89,6 +89,7 @@ int copy_thread(int nr, unsigned long cl
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 cl
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;
}
Index: linux/include/asm-mips/inst.h
===================================================================
--- linux.orig/include/asm-mips/inst.h 2005-03-15 10:09:23.000000000 -0500
+++ linux/include/asm-mips/inst.h 2005-03-15 10:09:29.000000000 -0500
@@ -28,7 +28,7 @@ enum major_op {
sdl_op, sdr_op, swr_op, cache_op,
ll_op, lwc1_op, lwc2_op, pref_op,
lld_op, ldc1_op, ldc2_op, ld_op,
- sc_op, swc1_op, swc2_op, major_3b_op, /* Opcode 0x3b is unused */
+ sc_op, swc1_op, swc2_op, rdhwr_op,
scd_op, sdc1_op, sdc2_op, sd_op
};
Index: linux/arch/mips/kernel/ptrace.c
===================================================================
--- linux.orig/arch/mips/kernel/ptrace.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/ptrace.c 2005-03-15 10:09:29.000000000 -0500
@@ -287,6 +287,11 @@ asmlinkage int sys_ptrace(long request,
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;
Index: linux/include/asm-mips/thread_info.h
===================================================================
--- linux.orig/include/asm-mips/thread_info.h 2005-03-15 10:09:23.000000000 -0500
+++ linux/include/asm-mips/thread_info.h 2005-03-15 10:34:51.000000000 -0500
@@ -26,6 +26,7 @@ struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
unsigned long flags; /* low level flags */
+ unsigned long tp_value; /* thread pointer */
__u32 cpu; /* current CPU */
__s32 preempt_count; /* 0 => preemptable, <0 => BUG */
Index: linux/arch/mips/kernel/offset.c
===================================================================
--- linux.orig/arch/mips/kernel/offset.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/offset.c 2005-03-15 10:09:29.000000000 -0500
@@ -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);
Index: linux/arch/mips/kernel/scall64-o32.S
===================================================================
--- linux.orig/arch/mips/kernel/scall64-o32.S 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/scall64-o32.S 2005-03-15 10:29:46.000000000 -0500
@@ -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
Index: linux/arch/mips/kernel/linux32.c
===================================================================
--- linux.orig/arch/mips/kernel/linux32.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/linux32.c 2005-03-15 10:29:02.000000000 -0500
@@ -1471,3 +1471,38 @@ sysn32_rt_sigtimedwait(const sigset_t __
}
return sys_rt_sigtimedwait(uthese, uinfo, uts, sigsetsize);
}
+
+save_static_function(sys32_clone);
+__attribute_used__ noinline static int
+_sys32_clone(unsigned long __dummy0,
+ unsigned long __dummy1,
+ unsigned long __dummy2,
+ unsigned long __dummy3,
+ unsigned long __dummy4,
+ unsigned long __dummy5,
+ unsigned long __dummy6,
+ unsigned long __dummy7,
+ 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, ®s, 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));
+}
Index: linux/arch/mips/kernel/ptrace32.c
===================================================================
--- linux.orig/arch/mips/kernel/ptrace32.c 2005-03-15 10:09:23.000000000 -0500
+++ linux/arch/mips/kernel/ptrace32.c 2005-03-15 10:09:29.000000000 -0500
@@ -268,6 +268,11 @@ asmlinkage int sys32_ptrace(int request,
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;
Index: linux/arch/mips/kernel/scall32-o32.S
===================================================================
--- linux.orig/arch/mips/kernel/scall32-o32.S 2005-03-15 10:04:30.000000000 -0500
+++ linux/arch/mips/kernel/scall32-o32.S 2005-03-15 10:29:24.000000000 -0500
@@ -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
Index: linux/include/asm-mips/unistd.h
===================================================================
--- linux.orig/include/asm-mips/unistd.h 2005-02-02 09:17:33.000000000 -0500
+++ linux/include/asm-mips/unistd.h 2005-03-15 10:26:02.000000000 -0500
@@ -303,16 +303,17 @@
#define __NR_add_key (__NR_Linux + 280)
#define __NR_request_key (__NR_Linux + 281)
#define __NR_keyctl (__NR_Linux + 282)
+#define __NR_set_thread_area (__NR_Linux + 283)
/*
* Offset of the last Linux o32 flavoured syscall
*/
-#define __NR_Linux_syscalls 282
+#define __NR_Linux_syscalls 283
#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
#define __NR_O32_Linux 4000
-#define __NR_O32_Linux_syscalls 282
+#define __NR_O32_Linux_syscalls 283
#if _MIPS_SIM == _MIPS_SIM_ABI64
@@ -562,16 +563,17 @@
#define __NR_add_key (__NR_Linux + 239)
#define __NR_request_key (__NR_Linux + 240)
#define __NR_keyctl (__NR_Linux + 241)
+#define __NR_set_thread_area (__NR_Linux + 242)
/*
* Offset of the last Linux 64-bit flavoured syscall
*/
-#define __NR_Linux_syscalls 241
+#define __NR_Linux_syscalls 242
#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
#define __NR_64_Linux 5000
-#define __NR_64_Linux_syscalls 241
+#define __NR_64_Linux_syscalls 242
#if _MIPS_SIM == _MIPS_SIM_NABI32
@@ -825,16 +827,17 @@
#define __NR_add_key (__NR_Linux + 243)
#define __NR_request_key (__NR_Linux + 244)
#define __NR_keyctl (__NR_Linux + 245)
+#define __NR_set_thread_area (__NR_Linux + 246)
/*
* Offset of the last N32 flavoured syscall
*/
-#define __NR_Linux_syscalls 245
+#define __NR_Linux_syscalls 246
#endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
#define __NR_N32_Linux 6000
-#define __NR_N32_Linux_syscalls 245
+#define __NR_N32_Linux_syscalls 246
#ifndef __ASSEMBLY__
Index: linux/arch/mips/kernel/scall64-64.S
===================================================================
--- linux.orig/arch/mips/kernel/scall64-64.S 2005-01-20 16:26:58.000000000 -0500
+++ linux/arch/mips/kernel/scall64-64.S 2005-03-15 10:29:48.000000000 -0500
@@ -449,3 +449,4 @@ sys_call_table:
PTR sys_add_key
PTR sys_request_key /* 5240 */
PTR sys_keyctl
+ PTR sys_set_thread_area
Index: linux/arch/mips/kernel/scall64-n32.S
===================================================================
--- linux.orig/arch/mips/kernel/scall64-n32.S 2005-03-15 10:09:21.000000000 -0500
+++ linux/arch/mips/kernel/scall64-n32.S 2005-03-16 09:04:03.388011517 -0500
@@ -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
--
Daniel Jacobowitz
CodeSourcery, LLC
