Revise MIPS 64-bit ptrace interface

    
Change the N32 debugging ABI to something more sane, and add support
for o32 and n32 debuggers to trace n64 programs.
    
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 222 insertions, 5 deletions

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 74283369a1e3..122433f835e3 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -38,6 +38,7 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/bootinfo.h>
+#include <asm/reg.h>
 
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -49,6 +50,118 @@ void ptrace_disable(struct task_struct *child)
         /* Nothing to do.. */
 }
 
+/*
+ * Read a general register set.  We always use the 64-bit format, even
+ * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
+ * Registers are sign extended to fill the available space.
+ */
+int ptrace_getregs (struct task_struct *child, __s64 __user *data)
+{
+        struct pt_regs *regs;
+        int i;
+
+        if (!access_ok(VERIFY_WRITE, data, 38 * 8))
+                return -EIO;
+
+        regs = (struct pt_regs *) ((unsigned long) child->thread_info +
+               THREAD_SIZE - 32 - sizeof(struct pt_regs));
+
+        for (i = 0; i < 32; i++)
+                __put_user (regs->regs[i], data + i);
+        __put_user (regs->lo, data + EF_LO - EF_R0);
+        __put_user (regs->hi, data + EF_HI - EF_R0);
+        __put_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
+        __put_user (regs->cp0_badvaddr, data + EF_CP0_BADVADDR - EF_R0);
+        __put_user (regs->cp0_status, data + EF_CP0_STATUS - EF_R0);
+        __put_user (regs->cp0_cause, data + EF_CP0_CAUSE - EF_R0);
+
+        return 0;
+}
+
+/*
+ * Write a general register set.  As for PTRACE_GETREGS, we always use
+ * the 64-bit format.  On a 32-bit kernel only the lower order half
+ * (according to endianness) will be used.
+ */
+int ptrace_setregs (struct task_struct *child, __s64 __user *data)
+{
+        struct pt_regs *regs;
+        int i;
+
+        if (!access_ok(VERIFY_READ, data, 38 * 8))
+                return -EIO;
+
+        regs = (struct pt_regs *) ((unsigned long) child->thread_info +
+               THREAD_SIZE - 32 - sizeof(struct pt_regs));
+
+        for (i = 0; i < 32; i++)
+                __get_user (regs->regs[i], data + i);
+        __get_user (regs->lo, data + EF_LO - EF_R0);
+        __get_user (regs->hi, data + EF_HI - EF_R0);
+        __get_user (regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
+
+        /* badvaddr, status, and cause may not be written.  */
+
+        return 0;
+}
+
+int ptrace_getfpregs (struct task_struct *child, __u32 __user *data)
+{
+        int i;
+
+        if (!access_ok(VERIFY_WRITE, data, 33 * 8))
+                return -EIO;
+
+        if (tsk_used_math(child)) {
+                fpureg_t *fregs = get_fpu_regs(child);
+                for (i = 0; i < 32; i++)
+                        __put_user (fregs[i], i + (__u64 __user *) data);
+        } else {
+                for (i = 0; i < 32; i++)
+                        __put_user ((__u64) -1, i + (__u64 __user *) data);
+        }
+
+        if (cpu_has_fpu) {
+                unsigned int flags, tmp;
+
+                __put_user (child->thread.fpu.hard.fcr31, data + 64);
+
+                flags = read_c0_status();
+                __enable_fpu();
+                __asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
+                write_c0_status(flags);
+                __put_user (tmp, data + 65);
+        } else {
+                __put_user (child->thread.fpu.soft.fcr31, data + 64);
+                __put_user ((__u32) 0, data + 65);
+        }
+
+        return 0;
+}
+
+int ptrace_setfpregs (struct task_struct *child, __u32 __user *data)
+{
+        fpureg_t *fregs;
+        int i;
+
+        if (!access_ok(VERIFY_READ, data, 33 * 8))
+                return -EIO;
+
+        fregs = get_fpu_regs(child);
+
+        for (i = 0; i < 32; i++)
+                __get_user (fregs[i], i + (__u64 __user *) data);
+
+        if (cpu_has_fpu)
+                __get_user (child->thread.fpu.hard.fcr31, data + 64);
+        else
+                __get_user (child->thread.fpu.soft.fcr31, data + 64);
+
+        /* FIR may not be written.  */
+
+        return 0;
+}
+
 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
 {
         struct task_struct *child;
@@ -300,6 +413,22 @@ asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
                 break;
                 }
 
+        case PTRACE_GETREGS:
+                ret = ptrace_getregs (child, (__u64 __user *) data);
+                break;
+
+        case PTRACE_SETREGS:
+                ret = ptrace_setregs (child, (__u64 __user *) data);
+                break;
+
+        case PTRACE_GETFPREGS:
+                ret = ptrace_getfpregs (child, (__u32 __user *) data);
+                break;
+
+        case PTRACE_SETFPREGS:
+                ret = ptrace_setfpregs (child, (__u32 __user *) data);
+                break;
+
         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
         case PTRACE_CONT: { /* restart after signal. */
                 ret = -EIO;
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index 5c45a5880226..c28cdddd4c21 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -35,6 +35,12 @@
 #include <asm/uaccess.h>
 #include <asm/bootinfo.h>
 
+int ptrace_getregs (struct task_struct *child, __s64 __user *data);
+int ptrace_setregs (struct task_struct *child, __s64 __user *data);
+
+int ptrace_getfpregs (struct task_struct *child, __u32 __user *data);
+int ptrace_setfpregs (struct task_struct *child, __u32 __user *data);
+
 /*
  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
  * work.  I don't know how to fix this.
@@ -99,6 +105,35 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                 break;
         }
 
+        /*
+         * Read 4 bytes of the other process' storage
+         *  data is a pointer specifying where the user wants the
+         *      4 bytes copied into
+         *  addr is a pointer in the user's storage that contains an 8 byte
+         *      address in the other process of the 4 bytes that is to be read
+         * (this is run in a 32-bit process looking at a 64-bit process)
+         * when I and D space are separate, these will need to be fixed.
+         */
+        case PTRACE_PEEKTEXT_3264:
+        case PTRACE_PEEKDATA_3264: {
+                u32 tmp;
+                int copied;
+                u32 __user * addrOthers;
+
+                ret = -EIO;
+
+                /* Get the addr in the other process that we want to read */
+                if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
+                        break;
+
+                copied = access_process_vm(child, (u64)addrOthers, &tmp,
+                                sizeof(tmp), 0);
+                if (copied != sizeof(tmp))
+                        break;
+                ret = put_user(tmp, (u32 __user *) (unsigned long) data);
+                break;
+        }
+
         /* Read the word at location addr in the USER area. */
         case PTRACE_PEEKUSR: {
                 struct pt_regs *regs;
@@ -202,6 +237,31 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                 ret = -EIO;
                 break;
 
+        /*
+         * Write 4 bytes into the other process' storage
+         *  data is the 4 bytes that the user wants written
+         *  addr is a pointer in the user's storage that contains an
+         *      8 byte address in the other process where the 4 bytes
+         *      that is to be written
+         * (this is run in a 32-bit process looking at a 64-bit process)
+         * when I and D space are separate, these will need to be fixed.
+         */
+        case PTRACE_POKETEXT_3264:
+        case PTRACE_POKEDATA_3264: {
+                u32 __user * addrOthers;
+
+                /* Get the addr in the other process that we want to write into */
+                ret = -EIO;
+                if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
+                        break;
+                ret = 0;
+                if (access_process_vm(child, (u64)addrOthers, &data,
+                                        sizeof(data), 1) == sizeof(data))
+                        break;
+                ret = -EIO;
+                break;
+        }
+
         case PTRACE_POKEUSR: {
                 struct pt_regs *regs;
                 ret = 0;
@@ -276,6 +336,22 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                 break;
                 }
 
+        case PTRACE_GETREGS:
+                ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
+                break;
+
+        case PTRACE_SETREGS:
+                ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
+                break;
+
+        case PTRACE_GETFPREGS:
+                ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
+                break;
+
+        case PTRACE_SETFPREGS:
+                ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
+                break;
+
         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
         case PTRACE_CONT: { /* restart after signal. */
                 ret = -EIO;
@@ -320,6 +396,11 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
                                (unsigned int __user *) (unsigned long) data);
                 break;
 
+        case PTRACE_GET_THREAD_AREA_3264:
+                ret = put_user(child->thread_info->tp_value,
+                                (unsigned long __user *) (unsigned long) data);
+                break;
+
         default:
                 ret = ptrace_request(child, request, addr, data);
                 break;
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index b32c566e0a24..7e66eb823bf6 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -216,7 +216,7 @@ EXPORT(sysn32_call_table)
         PTR     compat_sys_getrusage
         PTR     sys32_sysinfo
         PTR     compat_sys_times
-        PTR     sys_ptrace
+        PTR     sys32_ptrace
         PTR     sys_getuid                      /* 6100 */
         PTR     sys_syslog
         PTR     sys_getgid
diff --git a/include/asm-mips/ptrace.h b/include/asm-mips/ptrace.h
index 8441a5ae96e3..95c5839ac465 100644
--- a/include/asm-mips/ptrace.h
+++ b/include/asm-mips/ptrace.h
@@ -48,10 +48,10 @@ struct pt_regs {
 };
 
 /* Arbitrarily choose the same ptrace numbers as used by the Sparc code. */
-/* #define PTRACE_GETREGS               12 */
-/* #define PTRACE_SETREGS               13 */
-/* #define PTRACE_GETFPREGS             14 */
-/* #define PTRACE_SETFPREGS             15 */
+#define PTRACE_GETREGS          12
+#define PTRACE_SETREGS          13
+#define PTRACE_GETFPREGS                14
+#define PTRACE_SETFPREGS                15
 /* #define PTRACE_GETFPXREGS            18 */
 /* #define PTRACE_SETFPXREGS            19 */
 
@@ -60,6 +60,13 @@ struct pt_regs {
 #define PTRACE_GET_THREAD_AREA  25
 #define PTRACE_SET_THREAD_AREA  26
 
+/* Calls to trace a 64bit program from a 32bit program.  */
+#define PTRACE_PEEKTEXT_3264    0xc0
+#define PTRACE_PEEKDATA_3264    0xc1
+#define PTRACE_POKETEXT_3264    0xc2
+#define PTRACE_POKEDATA_3264    0xc3
+#define PTRACE_GET_THREAD_AREA_3264     0xc4
+
 #ifdef __KERNEL__
 
 #include <linux/linkage.h>