v4.19.13 snapshot.
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
new file mode 100644
index 0000000..24b0900
--- /dev/null
+++ b/arch/arm64/kernel/signal32.c
@@ -0,0 +1,516 @@
+/*
+ * Based on arch/arm/kernel/signal.c
+ *
+ * Copyright (C) 1995-2009 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ * Modified by Will Deacon <will.deacon@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compat.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/ratelimit.h>
+
+#include <asm/esr.h>
+#include <asm/fpsimd.h>
+#include <asm/signal32.h>
+#include <asm/traps.h>
+#include <linux/uaccess.h>
+#include <asm/unistd.h>
+
+struct compat_sigcontext {
+ /* We always set these two fields to 0 */
+ compat_ulong_t trap_no;
+ compat_ulong_t error_code;
+
+ compat_ulong_t oldmask;
+ compat_ulong_t arm_r0;
+ compat_ulong_t arm_r1;
+ compat_ulong_t arm_r2;
+ compat_ulong_t arm_r3;
+ compat_ulong_t arm_r4;
+ compat_ulong_t arm_r5;
+ compat_ulong_t arm_r6;
+ compat_ulong_t arm_r7;
+ compat_ulong_t arm_r8;
+ compat_ulong_t arm_r9;
+ compat_ulong_t arm_r10;
+ compat_ulong_t arm_fp;
+ compat_ulong_t arm_ip;
+ compat_ulong_t arm_sp;
+ compat_ulong_t arm_lr;
+ compat_ulong_t arm_pc;
+ compat_ulong_t arm_cpsr;
+ compat_ulong_t fault_address;
+};
+
+struct compat_ucontext {
+ compat_ulong_t uc_flags;
+ compat_uptr_t uc_link;
+ compat_stack_t uc_stack;
+ struct compat_sigcontext uc_mcontext;
+ compat_sigset_t uc_sigmask;
+ int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
+ compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
+};
+
+struct compat_vfp_sigframe {
+ compat_ulong_t magic;
+ compat_ulong_t size;
+ struct compat_user_vfp {
+ compat_u64 fpregs[32];
+ compat_ulong_t fpscr;
+ } ufp;
+ struct compat_user_vfp_exc {
+ compat_ulong_t fpexc;
+ compat_ulong_t fpinst;
+ compat_ulong_t fpinst2;
+ } ufp_exc;
+} __attribute__((__aligned__(8)));
+
+#define VFP_MAGIC 0x56465001
+#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
+
+#define FSR_WRITE_SHIFT (11)
+
+struct compat_aux_sigframe {
+ struct compat_vfp_sigframe vfp;
+
+ /* Something that isn't a valid magic number for any coprocessor. */
+ unsigned long end_magic;
+} __attribute__((__aligned__(8)));
+
+struct compat_sigframe {
+ struct compat_ucontext uc;
+ compat_ulong_t retcode[2];
+};
+
+struct compat_rt_sigframe {
+ struct compat_siginfo info;
+ struct compat_sigframe sig;
+};
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
+{
+ compat_sigset_t cset;
+
+ cset.sig[0] = set->sig[0] & 0xffffffffull;
+ cset.sig[1] = set->sig[0] >> 32;
+
+ return copy_to_user(uset, &cset, sizeof(*uset));
+}
+
+static inline int get_sigset_t(sigset_t *set,
+ const compat_sigset_t __user *uset)
+{
+ compat_sigset_t s32;
+
+ if (copy_from_user(&s32, uset, sizeof(*uset)))
+ return -EFAULT;
+
+ set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
+ return 0;
+}
+
+/*
+ * VFP save/restore code.
+ *
+ * We have to be careful with endianness, since the fpsimd context-switch
+ * code operates on 128-bit (Q) register values whereas the compat ABI
+ * uses an array of 64-bit (D) registers. Consequently, we need to swap
+ * the two halves of each Q register when running on a big-endian CPU.
+ */
+union __fpsimd_vreg {
+ __uint128_t raw;
+ struct {
+#ifdef __AARCH64EB__
+ u64 hi;
+ u64 lo;
+#else
+ u64 lo;
+ u64 hi;
+#endif
+ };
+};
+
+static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
+{
+ struct user_fpsimd_state const *fpsimd =
+ ¤t->thread.uw.fpsimd_state;
+ compat_ulong_t magic = VFP_MAGIC;
+ compat_ulong_t size = VFP_STORAGE_SIZE;
+ compat_ulong_t fpscr, fpexc;
+ int i, err = 0;
+
+ /*
+ * Save the hardware registers to the fpsimd_state structure.
+ * Note that this also saves V16-31, which aren't visible
+ * in AArch32.
+ */
+ fpsimd_signal_preserve_current_state();
+
+ /* Place structure header on the stack */
+ __put_user_error(magic, &frame->magic, err);
+ __put_user_error(size, &frame->size, err);
+
+ /*
+ * Now copy the FP registers. Since the registers are packed,
+ * we can copy the prefix we want (V0-V15) as it is.
+ */
+ for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
+ union __fpsimd_vreg vreg = {
+ .raw = fpsimd->vregs[i >> 1],
+ };
+
+ __put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
+ __put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
+ }
+
+ /* Create an AArch32 fpscr from the fpsr and the fpcr. */
+ fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
+ (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
+ __put_user_error(fpscr, &frame->ufp.fpscr, err);
+
+ /*
+ * The exception register aren't available so we fake up a
+ * basic FPEXC and zero everything else.
+ */
+ fpexc = (1 << 30);
+ __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
+ __put_user_error(0, &frame->ufp_exc.fpinst, err);
+ __put_user_error(0, &frame->ufp_exc.fpinst2, err);
+
+ return err ? -EFAULT : 0;
+}
+
+static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
+{
+ struct user_fpsimd_state fpsimd;
+ compat_ulong_t magic = VFP_MAGIC;
+ compat_ulong_t size = VFP_STORAGE_SIZE;
+ compat_ulong_t fpscr;
+ int i, err = 0;
+
+ __get_user_error(magic, &frame->magic, err);
+ __get_user_error(size, &frame->size, err);
+
+ if (err)
+ return -EFAULT;
+ if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
+ return -EINVAL;
+
+ /* Copy the FP registers into the start of the fpsimd_state. */
+ for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
+ union __fpsimd_vreg vreg;
+
+ __get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
+ __get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
+ fpsimd.vregs[i >> 1] = vreg.raw;
+ }
+
+ /* Extract the fpsr and the fpcr from the fpscr */
+ __get_user_error(fpscr, &frame->ufp.fpscr, err);
+ fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
+ fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
+
+ /*
+ * We don't need to touch the exception register, so
+ * reload the hardware state.
+ */
+ if (!err)
+ fpsimd_update_current_state(&fpsimd);
+
+ return err ? -EFAULT : 0;
+}
+
+static int compat_restore_sigframe(struct pt_regs *regs,
+ struct compat_sigframe __user *sf)
+{
+ int err;
+ sigset_t set;
+ struct compat_aux_sigframe __user *aux;
+ unsigned long psr;
+
+ err = get_sigset_t(&set, &sf->uc.uc_sigmask);
+ if (err == 0) {
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ set_current_blocked(&set);
+ }
+
+ __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
+ __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
+ __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
+ __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
+ __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
+ __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
+ __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
+ __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
+ __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
+ __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
+ __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
+ __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
+ __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
+ __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
+ __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
+ __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
+ __get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+ regs->pstate = compat_psr_to_pstate(psr);
+
+ /*
+ * Avoid compat_sys_sigreturn() restarting.
+ */
+ forget_syscall(regs);
+
+ err |= !valid_user_regs(®s->user_regs, current);
+
+ aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
+ if (err == 0)
+ err |= compat_restore_vfp_context(&aux->vfp);
+
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE0(sigreturn)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct compat_sigframe __user *frame;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Since we stacked the signal on a 64-bit boundary,
+ * then 'sp' should be word aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (regs->compat_sp & 7)
+ goto badframe;
+
+ frame = (struct compat_sigframe __user *)regs->compat_sp;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+ goto badframe;
+
+ if (compat_restore_sigframe(regs, frame))
+ goto badframe;
+
+ return regs->regs[0];
+
+badframe:
+ arm64_notify_segfault(regs->compat_sp);
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct compat_rt_sigframe __user *frame;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ /*
+ * Since we stacked the signal on a 64-bit boundary,
+ * then 'sp' should be word aligned here. If it's
+ * not, then the user is trying to mess with us.
+ */
+ if (regs->compat_sp & 7)
+ goto badframe;
+
+ frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+ goto badframe;
+
+ if (compat_restore_sigframe(regs, &frame->sig))
+ goto badframe;
+
+ if (compat_restore_altstack(&frame->sig.uc.uc_stack))
+ goto badframe;
+
+ return regs->regs[0];
+
+badframe:
+ arm64_notify_segfault(regs->compat_sp);
+ return 0;
+}
+
+static void __user *compat_get_sigframe(struct ksignal *ksig,
+ struct pt_regs *regs,
+ int framesize)
+{
+ compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
+ void __user *frame;
+
+ /*
+ * ATPCS B01 mandates 8-byte alignment
+ */
+ frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
+
+ /*
+ * Check that we can actually write to the signal frame.
+ */
+ if (!access_ok(VERIFY_WRITE, frame, framesize))
+ frame = NULL;
+
+ return frame;
+}
+
+static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+ compat_ulong_t __user *rc, void __user *frame,
+ int usig)
+{
+ compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
+ compat_ulong_t retcode;
+ compat_ulong_t spsr = regs->pstate & ~(PSR_f | PSR_AA32_E_BIT);
+ int thumb;
+
+ /* Check if the handler is written for ARM or Thumb */
+ thumb = handler & 1;
+
+ if (thumb)
+ spsr |= PSR_AA32_T_BIT;
+ else
+ spsr &= ~PSR_AA32_T_BIT;
+
+ /* The IT state must be cleared for both ARM and Thumb-2 */
+ spsr &= ~PSR_AA32_IT_MASK;
+
+ /* Restore the original endianness */
+ spsr |= PSR_AA32_ENDSTATE;
+
+ if (ka->sa.sa_flags & SA_RESTORER) {
+ retcode = ptr_to_compat(ka->sa.sa_restorer);
+ } else {
+ /* Set up sigreturn pointer */
+ unsigned int idx = thumb << 1;
+
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ idx += 3;
+
+ retcode = AARCH32_VECTORS_BASE +
+ AARCH32_KERN_SIGRET_CODE_OFFSET +
+ (idx << 2) + thumb;
+ }
+
+ regs->regs[0] = usig;
+ regs->compat_sp = ptr_to_compat(frame);
+ regs->compat_lr = retcode;
+ regs->pc = handler;
+ regs->pstate = spsr;
+}
+
+static int compat_setup_sigframe(struct compat_sigframe __user *sf,
+ struct pt_regs *regs, sigset_t *set)
+{
+ struct compat_aux_sigframe __user *aux;
+ unsigned long psr = pstate_to_compat_psr(regs->pstate);
+ int err = 0;
+
+ __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
+ __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
+ __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
+ __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
+ __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
+ __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
+ __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
+ __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
+ __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
+ __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
+ __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
+ __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
+ __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
+ __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
+ __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
+ __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
+ __put_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
+
+ __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
+ /* set the compat FSR WnR */
+ __put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
+ FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
+ __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
+ __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
+
+ err |= put_sigset_t(&sf->uc.uc_sigmask, set);
+
+ aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
+
+ if (err == 0)
+ err |= compat_preserve_vfp_context(&aux->vfp);
+ __put_user_error(0, &aux->end_magic, err);
+
+ return err;
+}
+
+/*
+ * 32-bit signal handling routines called from signal.c
+ */
+int compat_setup_rt_frame(int usig, struct ksignal *ksig,
+ sigset_t *set, struct pt_regs *regs)
+{
+ struct compat_rt_sigframe __user *frame;
+ int err = 0;
+
+ frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+
+ if (!frame)
+ return 1;
+
+ err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+
+ __put_user_error(0, &frame->sig.uc.uc_flags, err);
+ __put_user_error(0, &frame->sig.uc.uc_link, err);
+
+ err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
+
+ err |= compat_setup_sigframe(&frame->sig, regs, set);
+
+ if (err == 0) {
+ compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
+ regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
+ regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
+ }
+
+ return err;
+}
+
+int compat_setup_frame(int usig, struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ struct compat_sigframe __user *frame;
+ int err = 0;
+
+ frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+
+ if (!frame)
+ return 1;
+
+ __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
+
+ err |= compat_setup_sigframe(frame, regs, set);
+ if (err == 0)
+ compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
+
+ return err;
+}
+
+void compat_setup_restart_syscall(struct pt_regs *regs)
+{
+ regs->regs[7] = __NR_compat_restart_syscall;
+}