From: Jeff Dike Date: Sat, 10 Feb 2007 09:44:30 +0000 (-0800) Subject: [PATCH] uml: x86_64 ptrace fixes X-Git-Tag: v2.6.21-rc1~274^2~384 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e6d74cfac782a3a4cb5111bd9c25cd95d6b7c6c;p=linux-2.6 [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 Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index 9a77fb3c26..627742d894 100644 --- 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 147bbf05cb..55b66e09a9 100644 --- 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 f309fa9bc2..01b91f9fa7 100644 --- 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 a927450ce4..bf61d17de3 100644 --- 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