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 struct ucontextn32 { 37 u32 uc_flags; 38 s32 uc_link; 39 compat_stack_t uc_stack; 40 struct sigcontext uc_mcontext; 41 compat_sigset_t uc_sigmask; /* mask last for extensibility */ 42 }; 43 44 struct rt_sigframe_n32 { 45 u32 rs_ass[4]; /* argument save space for o32 */ 46 u32 rs_pad[2]; /* Was: signal trampoline */ 47 struct compat_siginfo rs_info; 48 struct ucontextn32 rs_uc; 49 }; 50 51 asmlinkage void sysn32_rt_sigreturn(void) 52 { 53 struct rt_sigframe_n32 __user *frame; 54 struct pt_regs *regs; 55 sigset_t set; 56 int sig; 57 58 regs = current_pt_regs(); 59 frame = (struct rt_sigframe_n32 __user *)regs->regs[29]; 60 if (!access_ok(frame, sizeof(*frame))) 61 goto badframe; 62 if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) 63 goto badframe; 64 65 set_current_blocked(&set); 66 67 sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); 68 if (sig < 0) 69 goto badframe; 70 else if (sig) 71 force_sig(sig); 72 73 if (compat_restore_altstack(&frame->rs_uc.uc_stack)) 74 goto badframe; 75 76 /* 77 * Don't let your children do this ... 78 */ 79 __asm__ __volatile__( 80 "move\t$29, %0\n\t" 81 "j\tsyscall_exit" 82 : /* no outputs */ 83 : "r" (regs)); 84 /* Unreached */ 85 86 badframe: 87 force_sig(SIGSEGV); 88 } 89 90 static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig, 91 struct pt_regs *regs, sigset_t *set) 92 { 93 struct rt_sigframe_n32 __user *frame; 94 int err = 0; 95 96 frame = get_sigframe(ksig, regs, sizeof(*frame)); 97 if (!access_ok(frame, sizeof (*frame))) 98 return -EFAULT; 99 100 /* Create siginfo. */ 101 err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info); 102 103 /* Create the ucontext. */ 104 err |= __put_user(0, &frame->rs_uc.uc_flags); 105 err |= __put_user(0, &frame->rs_uc.uc_link); 106 err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); 107 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); 108 err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); 109 110 if (err) 111 return -EFAULT; 112 113 /* 114 * Arguments to signal handler: 115 * 116 * a0 = signal number 117 * a1 = 0 (should be cause) 118 * a2 = pointer to ucontext 119 * 120 * $25 and c0_epc point to the signal handler, $29 points to 121 * the struct rt_sigframe. 122 */ 123 regs->regs[ 4] = ksig->sig; 124 regs->regs[ 5] = (unsigned long) &frame->rs_info; 125 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 126 regs->regs[29] = (unsigned long) frame; 127 regs->regs[31] = (unsigned long) sig_return; 128 regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; 129 130 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 131 current->comm, current->pid, 132 frame, regs->cp0_epc, regs->regs[31]); 133 134 return 0; 135 } 136 137 struct mips_abi mips_abi_n32 = { 138 .setup_rt_frame = setup_rt_frame_n32, 139 .restart = __NR_N32_restart_syscall, 140 141 .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), 142 .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), 143 .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), 144 145 .vdso = &vdso_image_n32, 146 }; 147