Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index cd4339b..d13b352 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for the ia32 kernel emulation subsystem.
 #
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index 8e02b30..9bb71ab 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  a.out loader for x86-64
  *
@@ -39,82 +40,10 @@
 static int load_aout_binary(struct linux_binprm *);
 static int load_aout_library(struct file *);
 
-#ifdef CONFIG_COREDUMP
-static int aout_core_dump(struct coredump_params *);
-
-static unsigned long get_dr(int n)
-{
-	struct perf_event *bp = current->thread.ptrace_bps[n];
-	return bp ? bp->hw.info.address : 0;
-}
-
-/*
- * fill in the user structure for a core dump..
- */
-static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
-{
-	u32 fs, gs;
-	memset(dump, 0, sizeof(*dump));
-
-/* changed the size calculations - should hopefully work better. lbt */
-	dump->magic = CMAGIC;
-	dump->start_code = 0;
-	dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
-	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
-	dump->u_dsize = ((unsigned long)
-			 (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
-	dump->u_dsize -= dump->u_tsize;
-	dump->u_debugreg[0] = get_dr(0);
-	dump->u_debugreg[1] = get_dr(1);
-	dump->u_debugreg[2] = get_dr(2);
-	dump->u_debugreg[3] = get_dr(3);
-	dump->u_debugreg[6] = current->thread.debugreg6;
-	dump->u_debugreg[7] = current->thread.ptrace_dr7;
-
-	if (dump->start_stack < 0xc0000000) {
-		unsigned long tmp;
-
-		tmp = (unsigned long) (0xc0000000 - dump->start_stack);
-		dump->u_ssize = tmp >> PAGE_SHIFT;
-	}
-
-	dump->regs.ebx = regs->bx;
-	dump->regs.ecx = regs->cx;
-	dump->regs.edx = regs->dx;
-	dump->regs.esi = regs->si;
-	dump->regs.edi = regs->di;
-	dump->regs.ebp = regs->bp;
-	dump->regs.eax = regs->ax;
-	dump->regs.ds = current->thread.ds;
-	dump->regs.es = current->thread.es;
-	savesegment(fs, fs);
-	dump->regs.fs = fs;
-	savesegment(gs, gs);
-	dump->regs.gs = gs;
-	dump->regs.orig_eax = regs->orig_ax;
-	dump->regs.eip = regs->ip;
-	dump->regs.cs = regs->cs;
-	dump->regs.eflags = regs->flags;
-	dump->regs.esp = regs->sp;
-	dump->regs.ss = regs->ss;
-
-#if 1 /* FIXME */
-	dump->u_fpvalid = 0;
-#else
-	dump->u_fpvalid = dump_fpu(regs, &dump->i387);
-#endif
-}
-
-#endif
-
 static struct linux_binfmt aout_format = {
 	.module		= THIS_MODULE,
 	.load_binary	= load_aout_binary,
 	.load_shlib	= load_aout_library,
-#ifdef CONFIG_COREDUMP
-	.core_dump	= aout_core_dump,
-#endif
-	.min_coredump	= PAGE_SIZE
 };
 
 static int set_brk(unsigned long start, unsigned long end)
@@ -126,91 +55,6 @@
 	return vm_brk(start, end - start);
 }
 
-#ifdef CONFIG_COREDUMP
-/*
- * These are the only things you should do on a core-file: use only these
- * macros to write out all the necessary info.
- */
-
-#include <linux/coredump.h>
-
-#define START_DATA(u)	(u.u_tsize << PAGE_SHIFT)
-#define START_STACK(u)	(u.start_stack)
-
-/*
- * Routine writes a core dump image in the current directory.
- * Currently only a stub-function.
- *
- * Note that setuid/setgid files won't make a core-dump if the uid/gid
- * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
- * field, which also makes sure the core-dumps won't be recursive if the
- * dumping of the process results in another error..
- */
-
-static int aout_core_dump(struct coredump_params *cprm)
-{
-	mm_segment_t fs;
-	int has_dumped = 0;
-	unsigned long dump_start, dump_size;
-	struct user32 dump;
-
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-	has_dumped = 1;
-	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
-	dump.u_ar0 = offsetof(struct user32, regs);
-	dump.signal = cprm->siginfo->si_signo;
-	dump_thread32(cprm->regs, &dump);
-
-	/*
-	 * If the size of the dump file exceeds the rlimit, then see
-	 * what would happen if we wrote the stack, but not the data
-	 * area.
-	 */
-	if ((dump.u_dsize + dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
-		dump.u_dsize = 0;
-
-	/* Make sure we have enough room to write the stack and data areas. */
-	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
-		dump.u_ssize = 0;
-
-	/* make sure we actually have a data and stack area to dump */
-	set_fs(USER_DS);
-	if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump),
-		       dump.u_dsize << PAGE_SHIFT))
-		dump.u_dsize = 0;
-	if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump),
-		       dump.u_ssize << PAGE_SHIFT))
-		dump.u_ssize = 0;
-
-	set_fs(KERNEL_DS);
-	/* struct user */
-	if (!dump_emit(cprm, &dump, sizeof(dump)))
-		goto end_coredump;
-	/* Now dump all of the user data.  Include malloced stuff as well */
-	if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
-		goto end_coredump;
-	/* now we start writing out the user space info */
-	set_fs(USER_DS);
-	/* Dump the data area */
-	if (dump.u_dsize != 0) {
-		dump_start = START_DATA(dump);
-		dump_size = dump.u_dsize << PAGE_SHIFT;
-		if (!dump_emit(cprm, (void *)dump_start, dump_size))
-			goto end_coredump;
-	}
-	/* Now prepare to dump the stack area */
-	if (dump.u_ssize != 0) {
-		dump_start = START_STACK(dump);
-		dump_size = dump.u_ssize << PAGE_SHIFT;
-		if (!dump_emit(cprm, (void *)dump_start, dump_size))
-			goto end_coredump;
-	}
-end_coredump:
-	set_fs(fs);
-	return has_dumped;
-}
-#endif
 
 /*
  * create_aout_tables() parses the env- and arg-strings in new user
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 86b1341..1cee100 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -61,9 +61,8 @@
 } while (0)
 
 #define RELOAD_SEG(seg)		{		\
-	unsigned int pre = GET_SEG(seg);	\
+	unsigned int pre = (seg) | 3;		\
 	unsigned int cur = get_user_seg(seg);	\
-	pre |= 3;				\
 	if (pre != cur)				\
 		set_user_seg(seg, pre);		\
 }
@@ -72,6 +71,7 @@
 				   struct sigcontext_32 __user *sc)
 {
 	unsigned int tmpflags, err = 0;
+	u16 gs, fs, es, ds;
 	void __user *buf;
 	u32 tmp;
 
@@ -79,16 +79,10 @@
 	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);
+		gs = GET_SEG(gs);
+		fs = GET_SEG(fs);
+		ds = GET_SEG(ds);
+		es = GET_SEG(es);
 
 		COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
 		COPY(dx); COPY(cx); COPY(ip); COPY(ax);
@@ -106,6 +100,17 @@
 		buf = compat_ptr(tmp);
 	} get_user_catch(err);
 
+	/*
+	 * 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);
+
 	err |= fpu__restore_sig(buf, 1);
 
 	force_iret();
@@ -119,7 +124,7 @@
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
 	sigset_t set;
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	if (__get_user(set.sig[0], &frame->sc.oldmask)
 	    || (_COMPAT_NSIG_WORDS > 1
@@ -147,7 +152,7 @@
 
 	frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
 
-	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 		goto badframe;
@@ -216,8 +221,7 @@
 				 size_t frame_size,
 				 void __user **fpstate)
 {
-	struct fpu *fpu = &current->thread.fpu;
-	unsigned long sp;
+	unsigned long sp, fx_aligned, math_size;
 
 	/* Default to using normal stack */
 	sp = regs->sp;
@@ -231,15 +235,11 @@
 		 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 = 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,
@@ -269,7 +269,7 @@
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
 
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		return -EFAULT;
 
 	if (__put_user(sig, &frame->sig))
@@ -349,7 +349,7 @@
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
 
-	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+	if (!access_ok(frame, sizeof(*frame)))
 		return -EFAULT;
 
 	put_user_try {
@@ -358,7 +358,7 @@
 		put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
 
 		/* Create the ucontext.  */
-		if (boot_cpu_has(X86_FEATURE_XSAVE))
+		if (static_cpu_has(X86_FEATURE_XSAVE))
 			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
 		else
 			put_user_ex(0, &frame->uc.uc_flags);
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 11ef7b7..2179030 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -75,7 +75,7 @@
 	typeof(ubuf->st_gid) gid = 0;
 	SET_UID(uid, from_kuid_munged(current_user_ns(), stat->uid));
 	SET_GID(gid, from_kgid_munged(current_user_ns(), stat->gid));
-	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(struct stat64)) ||
+	if (!access_ok(ubuf, sizeof(struct stat64)) ||
 	    __put_user(huge_encode_dev(stat->dev), &ubuf->st_dev) ||
 	    __put_user(stat->ino, &ubuf->__st_ino) ||
 	    __put_user(stat->ino, &ubuf->st_ino) ||
@@ -237,6 +237,18 @@
 		       unsigned long, newsp, int __user *, parent_tidptr,
 		       unsigned long, tls_val, int __user *, child_tidptr)
 {
-	return _do_fork(clone_flags, newsp, 0, parent_tidptr, child_tidptr,
-			tls_val);
+	struct kernel_clone_args args = {
+		.flags		= (clone_flags & ~CSIGNAL),
+		.pidfd		= parent_tidptr,
+		.child_tid	= child_tidptr,
+		.parent_tid	= parent_tidptr,
+		.exit_signal	= (clone_flags & CSIGNAL),
+		.stack		= newsp,
+		.tls		= tls_val,
+	};
+
+	if (!legacy_clone_args_valid(&args))
+		return -EINVAL;
+
+	return _do_fork(&args);
 }