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-rw-r--r--arch/s390/kernel/compat_signal.c428
1 files changed, 428 insertions, 0 deletions
diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
new file mode 100644
index 000000000..38d4bdbc3
--- /dev/null
+++ b/arch/s390/kernel/compat_signal.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2000, 2006
+ * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ * Gerhard Tonn (ton@de.ibm.com)
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
+ */
+
+#include <linux/compat.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/lowcore.h>
+#include <asm/switch_to.h>
+#include "compat_linux.h"
+#include "compat_ptrace.h"
+#include "entry.h"
+
+typedef struct
+{
+ __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
+ struct sigcontext32 sc;
+ _sigregs32 sregs;
+ int signo;
+ _sigregs_ext32 sregs_ext;
+ __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
+} sigframe32;
+
+typedef struct
+{
+ __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
+ __u16 svc_insn;
+ compat_siginfo_t info;
+ struct ucontext32 uc;
+} rt_sigframe32;
+
+/* Store registers needed to create the signal frame */
+static void store_sigregs(void)
+{
+ save_access_regs(current->thread.acrs);
+ save_fpu_regs();
+}
+
+/* Load registers after signal return */
+static void load_sigregs(void)
+{
+ restore_access_regs(current->thread.acrs);
+}
+
+static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
+{
+ _sigregs32 user_sregs;
+ int i;
+
+ user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
+ user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
+ user_sregs.regs.psw.mask |= PSW32_USER_BITS;
+ user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
+ (__u32)(regs->psw.mask & PSW_MASK_BA);
+ for (i = 0; i < NUM_GPRS; i++)
+ user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
+ memcpy(&user_sregs.regs.acrs, current->thread.acrs,
+ sizeof(user_sregs.regs.acrs));
+ fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
+ if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
+ return -EFAULT;
+ return 0;
+}
+
+static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
+{
+ _sigregs32 user_sregs;
+ int i;
+
+ /* Alwys make any pending restarted system call return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
+ return -EFAULT;
+
+ if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
+ return -EINVAL;
+
+ /* Test the floating-point-control word. */
+ if (test_fp_ctl(user_sregs.fpregs.fpc))
+ return -EINVAL;
+
+ /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
+ regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
+ (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
+ (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
+ (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
+ /* Check for invalid user address space control. */
+ if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
+ regs->psw.mask = PSW_ASC_PRIMARY |
+ (regs->psw.mask & ~PSW_MASK_ASC);
+ regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
+ for (i = 0; i < NUM_GPRS; i++)
+ regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
+ memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
+ sizeof(current->thread.acrs));
+ fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, &current->thread.fpu);
+
+ clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
+ return 0;
+}
+
+static int save_sigregs_ext32(struct pt_regs *regs,
+ _sigregs_ext32 __user *sregs_ext)
+{
+ __u32 gprs_high[NUM_GPRS];
+ __u64 vxrs[__NUM_VXRS_LOW];
+ int i;
+
+ /* Save high gprs to signal stack */
+ for (i = 0; i < NUM_GPRS; i++)
+ gprs_high[i] = regs->gprs[i] >> 32;
+ if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high,
+ sizeof(sregs_ext->gprs_high)))
+ return -EFAULT;
+
+ /* Save vector registers to signal stack */
+ if (MACHINE_HAS_VX) {
+ for (i = 0; i < __NUM_VXRS_LOW; i++)
+ vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
+ if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
+ sizeof(sregs_ext->vxrs_low)) ||
+ __copy_to_user(&sregs_ext->vxrs_high,
+ current->thread.fpu.vxrs + __NUM_VXRS_LOW,
+ sizeof(sregs_ext->vxrs_high)))
+ return -EFAULT;
+ }
+ return 0;
+}
+
+static int restore_sigregs_ext32(struct pt_regs *regs,
+ _sigregs_ext32 __user *sregs_ext)
+{
+ __u32 gprs_high[NUM_GPRS];
+ __u64 vxrs[__NUM_VXRS_LOW];
+ int i;
+
+ /* Restore high gprs from signal stack */
+ if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
+ sizeof(sregs_ext->gprs_high)))
+ return -EFAULT;
+ for (i = 0; i < NUM_GPRS; i++)
+ *(__u32 *)&regs->gprs[i] = gprs_high[i];
+
+ /* Restore vector registers from signal stack */
+ if (MACHINE_HAS_VX) {
+ if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
+ sizeof(sregs_ext->vxrs_low)) ||
+ __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
+ &sregs_ext->vxrs_high,
+ sizeof(sregs_ext->vxrs_high)))
+ return -EFAULT;
+ for (i = 0; i < __NUM_VXRS_LOW; i++)
+ *((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
+ }
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE0(sigreturn)
+{
+ struct pt_regs *regs = task_pt_regs(current);
+ sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
+ sigset_t set;
+
+ if (get_compat_sigset(&set, (compat_sigset_t __user *)frame->sc.oldmask))
+ goto badframe;
+ set_current_blocked(&set);
+ save_fpu_regs();
+ if (restore_sigregs32(regs, &frame->sregs))
+ goto badframe;
+ if (restore_sigregs_ext32(regs, &frame->sregs_ext))
+ goto badframe;
+ load_sigregs();
+ return regs->gprs[2];
+badframe:
+ force_sig(SIGSEGV);
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
+{
+ struct pt_regs *regs = task_pt_regs(current);
+ rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
+ sigset_t set;
+
+ if (get_compat_sigset(&set, &frame->uc.uc_sigmask))
+ goto badframe;
+ set_current_blocked(&set);
+ if (compat_restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+ save_fpu_regs();
+ if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+ if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
+ goto badframe;
+ load_sigregs();
+ return regs->gprs[2];
+badframe:
+ force_sig(SIGSEGV);
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = (unsigned long) A(regs->gprs[15]);
+
+ /* Overflow on alternate signal stack gives SIGSEGV. */
+ if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
+ return (void __user *) -1UL;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (! sas_ss_flags(sp))
+ sp = current->sas_ss_sp + current->sas_ss_size;
+ }
+
+ return (void __user *)((sp - frame_size) & -8ul);
+}
+
+static int setup_frame32(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ int sig = ksig->sig;
+ sigframe32 __user *frame;
+ unsigned long restorer;
+ size_t frame_size;
+
+ /*
+ * gprs_high are always present for 31-bit compat tasks.
+ * The space for vector registers is only allocated if
+ * the machine supports it
+ */
+ frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved);
+ if (!MACHINE_HAS_VX)
+ frame_size -= sizeof(frame->sregs_ext.vxrs_low) +
+ sizeof(frame->sregs_ext.vxrs_high);
+ frame = get_sigframe(&ksig->ka, regs, frame_size);
+ if (frame == (void __user *) -1UL)
+ return -EFAULT;
+
+ /* Set up backchain. */
+ if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
+ return -EFAULT;
+
+ /* Create struct sigcontext32 on the signal stack */
+ if (put_compat_sigset((compat_sigset_t __user *)frame->sc.oldmask,
+ set, sizeof(compat_sigset_t)))
+ return -EFAULT;
+ if (__put_user(ptr_to_compat(&frame->sregs), &frame->sc.sregs))
+ return -EFAULT;
+
+ /* Store registers needed to create the signal frame */
+ store_sigregs();
+
+ /* Create _sigregs32 on the signal stack */
+ if (save_sigregs32(regs, &frame->sregs))
+ return -EFAULT;
+
+ /* Place signal number on stack to allow backtrace from handler. */
+ if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
+ return -EFAULT;
+
+ /* Create _sigregs_ext32 on the signal stack */
+ if (save_sigregs_ext32(regs, &frame->sregs_ext))
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ restorer = (unsigned long __force)
+ ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
+ } else {
+ /* Signal frames without vectors registers are short ! */
+ __u16 __user *svc = (void __user *) frame + frame_size - 2;
+ if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
+ return -EFAULT;
+ restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
+ }
+
+ /* Set up registers for signal handler */
+ regs->gprs[14] = restorer;
+ regs->gprs[15] = (__force __u64) frame;
+ /* Force 31 bit amode and default user address space control. */
+ regs->psw.mask = PSW_MASK_BA |
+ (PSW_USER_BITS & PSW_MASK_ASC) |
+ (regs->psw.mask & ~PSW_MASK_ASC);
+ regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler;
+
+ regs->gprs[2] = sig;
+ regs->gprs[3] = (__force __u64) &frame->sc;
+
+ /* We forgot to include these in the sigcontext.
+ To avoid breaking binary compatibility, they are passed as args. */
+ if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
+ sig == SIGTRAP || sig == SIGFPE) {
+ /* set extra registers only for synchronous signals */
+ regs->gprs[4] = regs->int_code & 127;
+ regs->gprs[5] = regs->int_parm_long;
+ regs->gprs[6] = current->thread.last_break;
+ }
+
+ return 0;
+}
+
+static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ rt_sigframe32 __user *frame;
+ unsigned long restorer;
+ size_t frame_size;
+ u32 uc_flags;
+
+ frame_size = sizeof(*frame) -
+ sizeof(frame->uc.uc_mcontext_ext.__reserved);
+ /*
+ * gprs_high are always present for 31-bit compat tasks.
+ * The space for vector registers is only allocated if
+ * the machine supports it
+ */
+ uc_flags = UC_GPRS_HIGH;
+ if (MACHINE_HAS_VX) {
+ uc_flags |= UC_VXRS;
+ } else
+ frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) +
+ sizeof(frame->uc.uc_mcontext_ext.vxrs_high);
+ frame = get_sigframe(&ksig->ka, regs, frame_size);
+ if (frame == (void __user *) -1UL)
+ return -EFAULT;
+
+ /* Set up backchain. */
+ if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ restorer = (unsigned long __force)
+ ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
+ } else {
+ __u16 __user *svc = &frame->svc_insn;
+ if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
+ return -EFAULT;
+ restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
+ }
+
+ /* Create siginfo on the signal stack */
+ if (copy_siginfo_to_user32(&frame->info, &ksig->info))
+ return -EFAULT;
+
+ /* Store registers needed to create the signal frame */
+ store_sigregs();
+
+ /* Create ucontext on the signal stack. */
+ if (__put_user(uc_flags, &frame->uc.uc_flags) ||
+ __put_user(0, &frame->uc.uc_link) ||
+ __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
+ save_sigregs32(regs, &frame->uc.uc_mcontext) ||
+ put_compat_sigset(&frame->uc.uc_sigmask, set, sizeof(compat_sigset_t)) ||
+ save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->gprs[14] = restorer;
+ regs->gprs[15] = (__force __u64) frame;
+ /* Force 31 bit amode and default user address space control. */
+ regs->psw.mask = PSW_MASK_BA |
+ (PSW_USER_BITS & PSW_MASK_ASC) |
+ (regs->psw.mask & ~PSW_MASK_ASC);
+ regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler;
+
+ regs->gprs[2] = ksig->sig;
+ regs->gprs[3] = (__force __u64) &frame->info;
+ regs->gprs[4] = (__force __u64) &frame->uc;
+ regs->gprs[5] = current->thread.last_break;
+ return 0;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
+ struct pt_regs *regs)
+{
+ int ret;
+
+ /* Set up the stack frame */
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ ret = setup_rt_frame32(ksig, oldset, regs);
+ else
+ ret = setup_frame32(ksig, oldset, regs);
+
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
+}
+
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