cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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signal_n32.c (3819B)

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