1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2003 Broadcom Corporation 4 */ 5 #include <linux/cache.h> 6 #include <linux/sched.h> 7 #include <linux/mm.h> 8 #include <linux/smp.h> 9 #include <linux/kernel.h> 10 #include <linux/signal.h> 11 #include <linux/errno.h> 12 #include <linux/wait.h> 13 #include <linux/ptrace.h> 14 #include <linux/unistd.h> 15 #include <linux/compat.h> 16 #include <linux/bitops.h> 17 18 #include <asm/abi.h> 19 #include <asm/asm.h> 20 #include <asm/cacheflush.h> 21 #include <asm/compat-signal.h> 22 #include <asm/sim.h> 23 #include <linux/uaccess.h> 24 #include <asm/ucontext.h> 25 #include <asm/fpu.h> 26 #include <asm/cpu-features.h> 27 #include <asm/syscalls.h> 28 29 #include "signal-common.h" 30 31 /* 32 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... 33 */ 34 #define __NR_N32_restart_syscall 6214 35 36 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *); 37 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *); 38 39 struct ucontextn32 { 40 u32 uc_flags; 41 s32 uc_link; 42 compat_stack_t uc_stack; 43 struct sigcontext uc_mcontext; 44 compat_sigset_t uc_sigmask; /* mask last for extensibility */ 45 }; 46 47 struct rt_sigframe_n32 { 48 u32 rs_ass[4]; /* argument save space for o32 */ 49 u32 rs_pad[2]; /* Was: signal trampoline */ 50 struct compat_siginfo rs_info; 51 struct ucontextn32 rs_uc; 52 }; 53 54 asmlinkage void sysn32_rt_sigreturn(void) 55 { 56 struct rt_sigframe_n32 __user *frame; 57 struct pt_regs *regs; 58 sigset_t set; 59 int sig; 60 61 regs = current_pt_regs(); 62 frame = (struct rt_sigframe_n32 __user *)regs->regs[29]; 63 if (!access_ok(frame, sizeof(*frame))) 64 goto badframe; 65 if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) 66 goto badframe; 67 68 set_current_blocked(&set); 69 70 sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); 71 if (sig < 0) 72 goto badframe; 73 else if (sig) 74 force_sig(sig); 75 76 if (compat_restore_altstack(&frame->rs_uc.uc_stack)) 77 goto badframe; 78 79 /* 80 * Don't let your children do this ... 81 */ 82 __asm__ __volatile__( 83 "move\t$29, %0\n\t" 84 "j\tsyscall_exit" 85 : /* no outputs */ 86 : "r" (regs)); 87 /* Unreached */ 88 89 badframe: 90 force_sig(SIGSEGV); 91 } 92 93 static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig, 94 struct pt_regs *regs, sigset_t *set) 95 { 96 struct rt_sigframe_n32 __user *frame; 97 int err = 0; 98 99 frame = get_sigframe(ksig, regs, sizeof(*frame)); 100 if (!access_ok(frame, sizeof (*frame))) 101 return -EFAULT; 102 103 /* Create siginfo. */ 104 err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); 105 106 /* Create the ucontext. */ 107 err |= __put_user(0, &frame->rs_uc.uc_flags); 108 err |= __put_user(0, &frame->rs_uc.uc_link); 109 err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); 110 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); 111 err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); 112 113 if (err) 114 return -EFAULT; 115 116 /* 117 * Arguments to signal handler: 118 * 119 * a0 = signal number 120 * a1 = 0 (should be cause) 121 * a2 = pointer to ucontext 122 * 123 * $25 and c0_epc point to the signal handler, $29 points to 124 * the struct rt_sigframe. 125 */ 126 regs->regs[ 4] = ksig->sig; 127 regs->regs[ 5] = (unsigned long) &frame->rs_info; 128 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 129 regs->regs[29] = (unsigned long) frame; 130 regs->regs[31] = (unsigned long) sig_return; 131 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 132 133 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 134 current->comm, current->pid, 135 frame, regs->cp0_epc, regs->regs[31]); 136 137 return 0; 138 } 139 140 struct mips_abi mips_abi_n32 = { 141 .setup_rt_frame = setup_rt_frame_n32, 142 .restart = __NR_N32_restart_syscall, 143 144 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), 145 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), 146 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), 147 148 .vdso = &vdso_image_n32, 149 }; 150