From: Jeff Dike Some register accessor cleanups - userspace() was calling restore_registers and save_registers for no reason, since userspace() is on the libc side of the house, and these add no value over calling ptrace directly init_thread_registers and get_safe_registers were the same thing, so init_thread_registers is gone Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton --- arch/um/include/registers.h | 1 - arch/um/kernel/process.c | 2 +- arch/um/os-Linux/registers.c | 13 ++++--------- arch/um/os-Linux/skas/process.c | 11 ++++++++--- 4 files changed, 13 insertions(+), 14 deletions(-) diff -puN arch/um/include/registers.h~uml-use-ptrace-directly-in-libc-code arch/um/include/registers.h --- a/arch/um/include/registers.h~uml-use-ptrace-directly-in-libc-code +++ a/arch/um/include/registers.h @@ -9,7 +9,6 @@ #include "sysdep/ptrace.h" #include "sysdep/archsetjmp.h" -extern void init_thread_registers(struct uml_pt_regs *to); extern int save_fp_registers(int pid, unsigned long *fp_regs); extern int restore_fp_registers(int pid, unsigned long *fp_regs); extern int save_fpx_registers(int pid, unsigned long *fp_regs); diff -puN arch/um/kernel/process.c~uml-use-ptrace-directly-in-libc-code arch/um/kernel/process.c --- a/arch/um/kernel/process.c~uml-use-ptrace-directly-in-libc-code +++ a/arch/um/kernel/process.c @@ -199,7 +199,7 @@ int copy_thread(int nr, unsigned long cl arch_copy_thread(¤t->thread.arch, &p->thread.arch); } else { - init_thread_registers(&p->thread.regs.regs); + get_safe_registers(p->thread.regs.regs.gp); p->thread.request.u.thread = current->thread.request.u.thread; handler = new_thread_handler; } diff -puN arch/um/os-Linux/registers.c~uml-use-ptrace-directly-in-libc-code arch/um/os-Linux/registers.c --- a/arch/um/os-Linux/registers.c~uml-use-ptrace-directly-in-libc-code +++ a/arch/um/os-Linux/registers.c @@ -10,15 +10,6 @@ #include "sysdep/ptrace.h" #include "user.h" -/* This is set once at boot time and not changed thereafter */ - -static unsigned long exec_regs[MAX_REG_NR]; - -void init_thread_registers(struct uml_pt_regs *to) -{ - memcpy(to->gp, exec_regs, sizeof(to->gp)); -} - void save_registers(int pid, struct uml_pt_regs *regs) { int err; @@ -39,6 +30,10 @@ void restore_registers(int pid, struct u "errno = %d\n", errno); } +/* This is set once at boot time and not changed thereafter */ + +static unsigned long exec_regs[MAX_REG_NR]; + void init_registers(int pid) { int err; diff -puN arch/um/os-Linux/skas/process.c~uml-use-ptrace-directly-in-libc-code arch/um/os-Linux/skas/process.c --- a/arch/um/os-Linux/skas/process.c~uml-use-ptrace-directly-in-libc-code +++ a/arch/um/os-Linux/skas/process.c @@ -298,7 +298,9 @@ void userspace(struct uml_pt_regs *regs) nsecs += os_nsecs(); while (1) { - restore_registers(pid, regs); + if (ptrace(PTRACE_SETREGS, pid, 0, regs->gp)) + panic("userspace - PTRACE_SETREGS failed, " + "errno = %d\n", errno); /* Now we set local_using_sysemu to be used for one loop */ local_using_sysemu = get_using_sysemu(); @@ -318,7 +320,10 @@ void userspace(struct uml_pt_regs *regs) errno); regs->is_user = 1; - save_registers(pid, regs); + if (ptrace(PTRACE_GETREGS, pid, 0, regs->gp)) + panic("userspace - saving registers failed, " + "errno = %d\n", errno); + UPT_SYSCALL_NR(regs) = -1; /* Assume: It's not a syscall */ if (WIFSTOPPED(status)) { @@ -341,7 +346,7 @@ void userspace(struct uml_pt_regs *regs) break; case SIGVTALRM: now = os_nsecs(); - if(now < nsecs) + if (now < nsecs) break; block_signals(); (*sig_info[sig])(sig, regs); _