arch/um/kernel/frame_kern.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "asm/ptrace.h"
   7 #include "asm/uaccess.h"
   8 #include "asm/signal.h"
   9 #include "asm/ucontext.h"
  10 #include "frame_kern.h"
  11 #include "sigcontext.h"
  12 #include "sysdep/ptrace.h"
  13 #include "choose-mode.h"
  14 #include "mode.h"
  15
  16 static int copy_restorer(void (*restorer)(void), unsigned long start,
  17                          unsigned long sr_index, int sr_relative)
  18 {
  19         unsigned long sr;
  20
  21         if(sr_relative){
  22                 sr = (unsigned long) restorer;
  23                 sr += start + sr_index;
  24                 restorer = (void (*)(void)) sr;
  25         }
  26
  27         return(copy_to_user((void *) (start + sr_index), &restorer,
  28                             sizeof(restorer)));
  29 }
  30
  31 extern int userspace_pid[];
  32
  33 static int copy_sc_to_user(void *to, void *fp, struct pt_regs *from,
  34                            struct arch_frame_data *arch)
  35 {
  36         return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
  37                                               arch),
  38                            copy_sc_to_user_skas(userspace_pid[0], to, fp,
  39                                                 &from->regs,
  40                                                 current->thread.cr2,
  41                                                 current->thread.err)));
  42 }
  43
  44 static int copy_ucontext_to_user(struct ucontext *uc, void *fp, sigset_t *set,
  45                                  unsigned long sp)
  46 {
  47         int err = 0;
  48
  49         err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
  50         err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
  51         err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
  52         err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs,
  53                                &signal_frame_si.common.arch);
  54         err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
  55         return(err);
  56 }
  57
  58 int setup_signal_stack_si(unsigned long stack_top, int sig,
  59                           unsigned long handler, void (*restorer)(void),
  60                           struct pt_regs *regs, siginfo_t *info,
  61                           sigset_t *mask)
  62 {
  63         unsigned long start;
  64         void *sip, *ucp, *fp;
  65
  66         start = stack_top - signal_frame_si.common.len;
  67         sip = (void *) (start + signal_frame_si.si_index);
  68         ucp = (void *) (start + signal_frame_si.uc_index);
  69         fp = (void *) (((unsigned long) ucp) + sizeof(struct ucontext));
  70
  71         if(restorer == NULL)
  72                 panic("setup_signal_stack_si - no restorer");
  73
  74         if(copy_to_user((void *) start, signal_frame_si.common.data,
  75                         signal_frame_si.common.len) ||
  76            copy_to_user((void *) (start + signal_frame_si.common.sig_index),
  77                         &sig, sizeof(sig)) ||
  78            copy_siginfo_to_user(sip, info) ||
  79            copy_to_user((void *) (start + signal_frame_si.sip_index), &sip,
  80                         sizeof(sip)) ||
  81            copy_ucontext_to_user(ucp, fp, mask, PT_REGS_SP(regs)) ||
  82            copy_to_user((void *) (start + signal_frame_si.ucp_index), &ucp,
  83                         sizeof(ucp)) ||
  84            copy_restorer(restorer, start, signal_frame_si.common.sr_index,
  85                          signal_frame_si.common.sr_relative))
  86                 return(1);
  87
  88         PT_REGS_IP(regs) = handler;
  89         PT_REGS_SP(regs) = start + signal_frame_si.common.sp_index;
  90         return(0);
  91 }
  92
  93 int setup_signal_stack_sc(unsigned long stack_top, int sig,
  94                           unsigned long handler, void (*restorer)(void),
  95                           struct pt_regs *regs, sigset_t *mask)
  96 {
  97         struct frame_common *frame = &signal_frame_sc_sr.common;
  98         void *user_sc;
  99         int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
 100         unsigned long sigs, sr;
 101         unsigned long start = stack_top - frame->len - sig_size;
 102
 103         user_sc = (void *) (start + signal_frame_sc_sr.sc_index);
 104         if(restorer == NULL){
 105                 frame = &signal_frame_sc.common;
 106                 user_sc = (void *) (start + signal_frame_sc.sc_index);
 107                 sr = (unsigned long) frame->data;
 108                 sr += frame->sr_index;
 109                 sr = *((unsigned long *) sr);
 110                 restorer = ((void (*)(void)) sr);
 111         }
 112
 113         sigs = start + frame->len;
 114         if(copy_to_user((void *) start, frame->data, frame->len) ||
 115            copy_to_user((void *) (start + frame->sig_index), &sig,
 116                         sizeof(sig)) ||
 117            copy_sc_to_user(user_sc, NULL, regs,
 118                            &signal_frame_sc.common.arch) ||
 119            copy_to_user(sc_sigmask(user_sc), mask, sizeof(mask->sig[0])) ||
 120            copy_to_user((void *) sigs, &mask->sig[1], sig_size) ||
 121            copy_restorer(restorer, start, frame->sr_index, frame->sr_relative))
 122                 return(1);
 123
 124         PT_REGS_IP(regs) = handler;
 125         PT_REGS_SP(regs) = start + frame->sp_index;
 126
 127         return(0);
 128 }
 129
 130 /*
 131  * Overrides for Emacs so that we follow Linus's tabbing style.
 132  * Emacs will notice this stuff at the end of the file and automatically
 133  * adjust the settings for this buffer only.  This must remain at the end
 134  * of the file.
 135  * ---------------------------------------------------------------------------
 136  * Local variables:
 137  * c-file-style: "linux"
 138  * End:
 139  */