v4.19.13 snapshot.
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
new file mode 100644
index 0000000..86b1341
--- /dev/null
+++ b/arch/x86/ia32/ia32_signal.c
@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/x86_64/ia32/ia32_signal.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
+ * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
+ * 2000-12-* x86-64 compatibility mode signal handling by Andi Kleen
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/compat.h>
+#include <linux/binfmts.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/fpu/internal.h>
+#include <asm/fpu/signal.h>
+#include <asm/ptrace.h>
+#include <asm/ia32_unistd.h>
+#include <asm/user32.h>
+#include <uapi/asm/sigcontext.h>
+#include <asm/proto.h>
+#include <asm/vdso.h>
+#include <asm/sigframe.h>
+#include <asm/sighandling.h>
+#include <asm/smap.h>
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+#define loadsegment_gs(v) load_gs_index(v)
+#define loadsegment_fs(v) loadsegment(fs, v)
+#define loadsegment_ds(v) loadsegment(ds, v)
+#define loadsegment_es(v) loadsegment(es, v)
+
+#define get_user_seg(seg) ({ unsigned int v; savesegment(seg, v); v; })
+#define set_user_seg(seg, v) loadsegment_##seg(v)
+
+#define COPY(x) { \
+ get_user_ex(regs->x, &sc->x); \
+}
+
+#define GET_SEG(seg) ({ \
+ unsigned short tmp; \
+ get_user_ex(tmp, &sc->seg); \
+ tmp; \
+})
+
+#define COPY_SEG_CPL3(seg) do { \
+ regs->seg = GET_SEG(seg) | 3; \
+} while (0)
+
+#define RELOAD_SEG(seg) { \
+ unsigned int pre = GET_SEG(seg); \
+ unsigned int cur = get_user_seg(seg); \
+ pre |= 3; \
+ if (pre != cur) \
+ set_user_seg(seg, pre); \
+}
+
+static int ia32_restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext_32 __user *sc)
+{
+ unsigned int tmpflags, err = 0;
+ void __user *buf;
+ u32 tmp;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ get_user_try {
+ /*
+ * Reload fs and gs if they have changed in the signal
+ * handler. This does not handle long fs/gs base changes in
+ * the handler, but does not clobber them at least in the
+ * normal case.
+ */
+ RELOAD_SEG(gs);
+ RELOAD_SEG(fs);
+ RELOAD_SEG(ds);
+ RELOAD_SEG(es);
+
+ COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+ COPY(dx); COPY(cx); COPY(ip); COPY(ax);
+ /* Don't touch extended registers */
+
+ COPY_SEG_CPL3(cs);
+ COPY_SEG_CPL3(ss);
+
+ get_user_ex(tmpflags, &sc->flags);
+ regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+ /* disable syscall checks */
+ regs->orig_ax = -1;
+
+ get_user_ex(tmp, &sc->fpstate);
+ buf = compat_ptr(tmp);
+ } get_user_catch(err);
+
+ err |= fpu__restore_sig(buf, 1);
+
+ force_iret();
+
+ return err;
+}
+
+asmlinkage long sys32_sigreturn(void)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
+ sigset_t set;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__get_user(set.sig[0], &frame->sc.oldmask)
+ || (_COMPAT_NSIG_WORDS > 1
+ && __copy_from_user((((char *) &set.sig) + 4),
+ &frame->extramask,
+ sizeof(frame->extramask))))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (ia32_restore_sigcontext(regs, &frame->sc))
+ goto badframe;
+ return regs->ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit sigreturn");
+ return 0;
+}
+
+asmlinkage long sys32_rt_sigreturn(void)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct rt_sigframe_ia32 __user *frame;
+ sigset_t set;
+
+ frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ if (compat_restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return regs->ax;
+
+badframe:
+ signal_fault(regs, frame, "32bit rt sigreturn");
+ return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
+ void __user *fpstate,
+ struct pt_regs *regs, unsigned int mask)
+{
+ int err = 0;
+
+ put_user_try {
+ put_user_ex(get_user_seg(gs), (unsigned int __user *)&sc->gs);
+ put_user_ex(get_user_seg(fs), (unsigned int __user *)&sc->fs);
+ put_user_ex(get_user_seg(ds), (unsigned int __user *)&sc->ds);
+ put_user_ex(get_user_seg(es), (unsigned int __user *)&sc->es);
+
+ put_user_ex(regs->di, &sc->di);
+ put_user_ex(regs->si, &sc->si);
+ put_user_ex(regs->bp, &sc->bp);
+ put_user_ex(regs->sp, &sc->sp);
+ put_user_ex(regs->bx, &sc->bx);
+ put_user_ex(regs->dx, &sc->dx);
+ put_user_ex(regs->cx, &sc->cx);
+ put_user_ex(regs->ax, &sc->ax);
+ put_user_ex(current->thread.trap_nr, &sc->trapno);
+ put_user_ex(current->thread.error_code, &sc->err);
+ put_user_ex(regs->ip, &sc->ip);
+ put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
+ put_user_ex(regs->flags, &sc->flags);
+ put_user_ex(regs->sp, &sc->sp_at_signal);
+ put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
+
+ put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);
+
+ /* non-iBCS2 extensions.. */
+ put_user_ex(mask, &sc->oldmask);
+ put_user_ex(current->thread.cr2, &sc->cr2);
+ } put_user_catch(err);
+
+ return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+ size_t frame_size,
+ void __user **fpstate)
+{
+ struct fpu *fpu = ¤t->thread.fpu;
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->sp;
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ksig->ka.sa.sa_flags & SA_ONSTACK)
+ sp = sigsp(sp, ksig);
+ /* This is the legacy signal stack switching. */
+ else if (regs->ss != __USER32_DS &&
+ !(ksig->ka.sa.sa_flags & SA_RESTORER) &&
+ ksig->ka.sa.sa_restorer)
+ sp = (unsigned long) ksig->ka.sa.sa_restorer;
+
+ if (fpu->initialized) {
+ unsigned long fx_aligned, math_size;
+
+ sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
+ *fpstate = (struct _fpstate_32 __user *) sp;
+ if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
+ math_size) < 0)
+ return (void __user *) -1L;
+ }
+
+ sp -= frame_size;
+ /* Align the stack pointer according to the i386 ABI,
+ * i.e. so that on function entry ((sp + 4) & 15) == 0. */
+ sp = ((sp + 4) & -16ul) - 4;
+ return (void __user *) sp;
+}
+
+int ia32_setup_frame(int sig, struct ksignal *ksig,
+ compat_sigset_t *set, struct pt_regs *regs)
+{
+ struct sigframe_ia32 __user *frame;
+ void __user *restorer;
+ int err = 0;
+ void __user *fpstate = NULL;
+
+ /* copy_to_user optimizes that into a single 8 byte store */
+ static const struct {
+ u16 poplmovl;
+ u32 val;
+ u16 int80;
+ } __attribute__((packed)) code = {
+ 0xb858, /* popl %eax ; movl $...,%eax */
+ __NR_ia32_sigreturn,
+ 0x80cd, /* int $0x80 */
+ };
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ if (__put_user(sig, &frame->sig))
+ return -EFAULT;
+
+ if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
+ return -EFAULT;
+
+ if (_COMPAT_NSIG_WORDS > 1) {
+ if (__copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask)))
+ return -EFAULT;
+ }
+
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ restorer = ksig->ka.sa.sa_restorer;
+ } else {
+ /* Return stub is in 32bit vsyscall page */
+ if (current->mm->context.vdso)
+ restorer = current->mm->context.vdso +
+ vdso_image_32.sym___kernel_sigreturn;
+ else
+ restorer = &frame->retcode;
+ }
+
+ put_user_try {
+ put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
+
+ /*
+ * These are actually not used anymore, but left because some
+ * gdb versions depend on them as a marker.
+ */
+ put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
+ } put_user_catch(err);
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long) frame;
+ regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->ax = sig;
+ regs->dx = 0;
+ regs->cx = 0;
+
+ loadsegment(ds, __USER32_DS);
+ loadsegment(es, __USER32_DS);
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER32_DS;
+
+ return 0;
+}
+
+int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
+ compat_sigset_t *set, struct pt_regs *regs)
+{
+ struct rt_sigframe_ia32 __user *frame;
+ void __user *restorer;
+ int err = 0;
+ void __user *fpstate = NULL;
+
+ /* __copy_to_user optimizes that into a single 8 byte store */
+ static const struct {
+ u8 movl;
+ u32 val;
+ u16 int80;
+ u8 pad;
+ } __attribute__((packed)) code = {
+ 0xb8,
+ __NR_ia32_rt_sigreturn,
+ 0x80cd,
+ 0,
+ };
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ put_user_try {
+ put_user_ex(sig, &frame->sig);
+ put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
+ put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
+
+ /* Create the ucontext. */
+ if (boot_cpu_has(X86_FEATURE_XSAVE))
+ put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
+ else
+ put_user_ex(0, &frame->uc.uc_flags);
+ put_user_ex(0, &frame->uc.uc_link);
+ compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
+
+ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = ksig->ka.sa.sa_restorer;
+ else
+ restorer = current->mm->context.vdso +
+ vdso_image_32.sym___kernel_rt_sigreturn;
+ put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
+
+ /*
+ * Not actually used anymore, but left because some gdb
+ * versions need it.
+ */
+ put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
+ } put_user_catch(err);
+
+ err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
+ err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+ regs, set->sig[0]);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long) frame;
+ regs->ip = (unsigned long) ksig->ka.sa.sa_handler;
+
+ /* Make -mregparm=3 work */
+ regs->ax = sig;
+ regs->dx = (unsigned long) &frame->info;
+ regs->cx = (unsigned long) &frame->uc;
+
+ loadsegment(ds, __USER32_DS);
+ loadsegment(es, __USER32_DS);
+
+ regs->cs = __USER32_CS;
+ regs->ss = __USER32_DS;
+
+ return 0;
+}