[PATCH] uml: x86_64 ptrace fixes

This patch fixes some missing ptrace bits on x86_64.  PTRACE_ARCH_PRCTL is
hooked up and implemented.  This required generalizing arch_prctl_skas
slightly to take a task_struct to modify.  Previously, it always operated on
current.

Reading and writing the debug registers is also enabled by un-ifdefing the
code that implements that.  It turns out that x86_64 is identical to i386, so
the same code can be used.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 9a77fb3c269d667d122c628fec3dd90d8fc4222a..627742d894347c7ca6eb51f989b1e4c259de0909 100644 (file)
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -18,6 +18,7 @@
 #include "kern_util.h"
 #include "skas_ptrace.h"
 #include "sysdep/ptrace.h"
+#include "os.h"
 
 static inline void set_singlestepping(struct task_struct *child, int on)
 {
@@ -240,6 +241,12 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                ret = 0;
                break;
        }
+#endif
+#ifdef PTRACE_ARCH_PRCTL
+        case PTRACE_ARCH_PRCTL:
+                /* XXX Calls ptrace on the host - needs some SMP thinking */
+                ret = arch_prctl_skas(child, data, (void *) addr);
+                break;
 #endif
        default:
                ret = ptrace_request(child, request, addr, data);

diff --git a/arch/um/sys-x86_64/ptrace.c b/arch/um/sys-x86_64/ptrace.c
index 147bbf05cbc2fbc2d71e395f038ac97ce0387902..55b66e09a98cce2437969f49fdc477e08bb92311 100644 (file)
--- a/arch/um/sys-x86_64/ptrace.c
+++ b/arch/um/sys-x86_64/ptrace.c
@@ -71,8 +71,6 @@ int poke_user(struct task_struct *child, long addr, long data)
 
         if (addr < MAX_REG_OFFSET)
                 return putreg(child, addr, data);
-
-#if 0 /* Need x86_64 debugregs handling */
         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
                 (addr <= offsetof(struct user, u_debugreg[7]))){
                 addr -= offsetof(struct user, u_debugreg[0]);
@@ -81,7 +79,6 @@ int poke_user(struct task_struct *child, long addr, long data)
                 child->thread.arch.debugregs[addr] = data;
                 return 0;
         }
-#endif
         return -EIO;
 }
 
@@ -119,14 +116,12 @@ int peek_user(struct task_struct *child, long addr, long data)
         if(addr < MAX_REG_OFFSET){
                 tmp = getreg(child, addr);
         }
-#if 0 /* Need x86_64 debugregs handling */
         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
                 (addr <= offsetof(struct user, u_debugreg[7]))){
                 addr -= offsetof(struct user, u_debugreg[0]);
                 addr = addr >> 2;
                 tmp = child->thread.arch.debugregs[addr];
         }
-#endif
         return put_user(tmp, (unsigned long *) data);
 }
 

diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index f309fa9bc23225ce43d4ce2bcb69dc3d48f75da9..01b91f9fa7893647454f2a843f22a729197d78cb 100644 (file)
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -59,18 +59,20 @@ static long arch_prctl_tt(int code, unsigned long addr)
 
 #ifdef CONFIG_MODE_SKAS
 
-static long arch_prctl_skas(int code, unsigned long __user *addr)
+long arch_prctl_skas(struct task_struct *task, int code,
+                     unsigned long __user *addr)
 {
         unsigned long *ptr = addr, tmp;
        long ret;
-        int pid = current->mm->context.skas.id.u.pid;
+       int pid = task->mm->context.skas.id.u.pid;
 
        /*
         * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
         * be safe), we need to call arch_prctl on the host because
         * setting %fs may result in something else happening (like a
-        * GDT being set instead).  So, we let the host fiddle the
-        * registers and restore them afterwards.
+        * GDT or thread.fs being set instead).  So, we let the host
+        * fiddle the registers and thread struct and restore the
+        * registers afterwards.
         *
         * So, the saved registers are stored to the process (this
         * needed because a stub may have been the last thing to run),
@@ -118,7 +120,7 @@ static long arch_prctl_skas(int code, unsigned long __user *addr)
 
 long sys_arch_prctl(int code, unsigned long addr)
 {
-       return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code,
+       return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, current, code,
                                 (unsigned long __user *) addr);
 }
 
@@ -141,6 +143,6 @@ void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
         if(to->thread.arch.fs == 0)
                 return;
 
-        arch_prctl_skas(ARCH_SET_FS, (void __user *) to->thread.arch.fs);
+        arch_prctl_skas(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
 }
 

diff --git a/include/asm-um/ptrace-x86_64.h b/include/asm-um/ptrace-x86_64.h
index a927450ce4011c460b115b57357801fbb9f6201f..bf61d17de3f72d776a2f5ba3e6e1017c6884101d 100644 (file)
--- a/include/asm-um/ptrace-x86_64.h
+++ b/include/asm-um/ptrace-x86_64.h
@@ -84,4 +84,7 @@ static inline void arch_switch_to_tt(struct task_struct *from,
 extern void arch_switch_to_skas(struct task_struct *from,
                                struct task_struct *to);
 
+extern long arch_prctl_skas(struct task_struct *task, int code,
+                           unsigned long __user *addr);
+
 #endif