9 files changed, 60 insertions, 77 deletions
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index f8567b933ffa..4df1cd0d2017 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -17,7 +17,7 @@ extra-y := vmlinux.lds
 obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \
 	physmem.o process.o ptrace.o reboot.o sigio.o \
 	signal.o sysrq.o time.o tlb.o trap.o \
-	um_arch.o umid.o maccess.o kmsg_dump.o capflags.o skas/
+	um_arch.o umid.o kmsg_dump.o capflags.o skas/
 obj-y += load_file.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index a4991746f5ea..abe8f30a521c 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -236,7 +236,8 @@ static void _sigio_handler(struct uml_pt_regs *regs,
 		free_irqs();
 }
 
-void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
+void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
+		   void *mc)
 {
 	preempt_disable();
 	_sigio_handler(regs, irqs_suspended);
diff --git a/arch/um/kernel/maccess.c b/arch/um/kernel/maccess.c
deleted file mode 100644
index 8ccd56813f68..000000000000
--- a/arch/um/kernel/maccess.c
+++ /dev/null
@@ -1,19 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
- */
-
-#include <linux/uaccess.h>
-#include <linux/kernel.h>
-#include <os.h>
-
-bool copy_from_kernel_nofault_allowed(const void *src, size_t size)
-{
-	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
-
-	if ((unsigned long)src < PAGE_SIZE || size <= 0)
-		return false;
-	if (os_mincore(psrc, size + src - psrc) <= 0)
-		return false;
-	return true;
-}
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index befed230aac2..76bec7de81b5 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -9,6 +9,8 @@
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/slab.h>
+#include <linux/init.h>
+#include <asm/sections.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
 #include <as-layout.h>
@@ -54,7 +56,7 @@ int kmalloc_ok = 0;
 /* Used during early boot */
 static unsigned long brk_end;
 
-void __init mem_init(void)
+void __init arch_mm_preinit(void)
 {
 	/* clear the zero-page */
 	memset(empty_zero_page, 0, PAGE_SIZE);
@@ -66,10 +68,12 @@ void __init mem_init(void)
 	map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
 	memblock_free((void *)brk_end, uml_reserved - brk_end);
 	uml_reserved = brk_end;
-
-	/* this will put all low memory onto the freelists */
-	memblock_free_all();
+	min_low_pfn = PFN_UP(__pa(uml_reserved));
 	max_pfn = max_low_pfn;
+}
+
+void __init mem_init(void)
+{
 	kmalloc_ok = 1;
 }
 
@@ -241,3 +245,11 @@ static const pgprot_t protection_map[16] = {
 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED
 };
 DECLARE_VM_GET_PAGE_PROT
+
+void mark_rodata_ro(void)
+{
+	unsigned long rodata_start = PFN_ALIGN(__start_rodata);
+	unsigned long rodata_end = PFN_ALIGN(__end_rodata);
+
+	os_protect_memory((void *)rodata_start, rodata_end - rodata_start, 1, 0, 0);
+}
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index a74f17b033c4..af02b5f9911d 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -22,18 +22,6 @@ static int physmem_fd = -1;
 unsigned long high_physmem;
 EXPORT_SYMBOL(high_physmem);
 
-void __init mem_total_pages(unsigned long physmem, unsigned long iomem)
-{
-	unsigned long phys_pages, iomem_pages, total_pages;
-
-	phys_pages  = physmem >> PAGE_SHIFT;
-	iomem_pages = iomem   >> PAGE_SHIFT;
-
-	total_pages = phys_pages + iomem_pages;
-
-	max_mapnr = total_pages;
-}
-
 void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
 		int r, int w, int x)
 {
diff --git a/arch/um/kernel/sigio.c b/arch/um/kernel/sigio.c
index 5085a50c3b8c..4fc04742048a 100644
--- a/arch/um/kernel/sigio.c
+++ b/arch/um/kernel/sigio.c
@@ -8,32 +8,6 @@
 #include <os.h>
 #include <sigio.h>
 
-/* Protected by sigio_lock() called from write_sigio_workaround */
-static int sigio_irq_fd = -1;
-
-static irqreturn_t sigio_interrupt(int irq, void *data)
-{
-	char c;
-
-	os_read_file(sigio_irq_fd, &c, sizeof(c));
-	return IRQ_HANDLED;
-}
-
-int write_sigio_irq(int fd)
-{
-	int err;
-
-	err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
-			     0, "write sigio", NULL);
-	if (err < 0) {
-		printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
-		       "err = %d\n", err);
-		return -1;
-	}
-	sigio_irq_fd = fd;
-	return 0;
-}
-
 /* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
 static DEFINE_MUTEX(sigio_mutex);
 
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index b09e85279d2b..a5beaea2967e 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -31,6 +31,17 @@ void handle_syscall(struct uml_pt_regs *r)
 		goto out;
 
 	syscall = UPT_SYSCALL_NR(r);
+
+	/*
+	 * If no time passes, then sched_yield may not actually yield, causing
+	 * broken spinlock implementations in userspace (ASAN) to hang for long
+	 * periods of time.
+	 */
+	if ((time_travel_mode == TT_MODE_INFCPU ||
+	     time_travel_mode == TT_MODE_EXTERNAL) &&
+	    syscall == __NR_sched_yield)
+		tt_extra_sched_jiffies += 1;
+
 	if (syscall >= 0 && syscall < __NR_syscalls) {
 		unsigned long ret = EXECUTE_SYSCALL(syscall, regs);
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index cdaee3e94273..ce073150dc20 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -16,6 +16,7 @@
 #include <kern_util.h>
 #include <os.h>
 #include <skas.h>
+#include <arch.h>
 
 /*
  * Note this is constrained to return 0, -EFAULT, -EACCES, -ENOMEM by
@@ -175,12 +176,14 @@ void fatal_sigsegv(void)
  * @sig:	the signal number
  * @unused_si:	the signal info struct; unused in this handler
  * @regs:	the ptrace register information
+ * @mc:		the mcontext of the signal
  *
  * The handler first extracts the faultinfo from the UML ptrace regs struct.
  * If the userfault did not happen in an UML userspace process, bad_segv is called.
  * Otherwise the signal did happen in a cloned userspace process, handle it.
  */
-void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
+void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
+		  void *mc)
 {
 	struct faultinfo * fi = UPT_FAULTINFO(regs);
 
@@ -189,7 +192,7 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 		bad_segv(*fi, UPT_IP(regs));
 		return;
 	}
-	segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
+	segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs, mc);
 }
 
 /*
@@ -199,7 +202,7 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
  * give us bad data!
  */
 unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
-		   struct uml_pt_regs *regs)
+		   struct uml_pt_regs *regs, void *mc)
 {
 	int si_code;
 	int err;
@@ -223,6 +226,19 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		goto out;
 	}
 	else if (current->mm == NULL) {
+		if (current->pagefault_disabled) {
+			if (!mc) {
+				show_regs(container_of(regs, struct pt_regs, regs));
+				panic("Segfault with pagefaults disabled but no mcontext");
+			}
+			if (!current->thread.segv_continue) {
+				show_regs(container_of(regs, struct pt_regs, regs));
+				panic("Segfault without recovery target");
+			}
+			mc_set_rip(mc, current->thread.segv_continue);
+			current->thread.segv_continue = NULL;
+			goto out;
+		}
 		show_regs(container_of(regs, struct pt_regs, regs));
 		panic("Segfault with no mm");
 	}
@@ -274,7 +290,8 @@ out:
 	return 0;
 }
 
-void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
+void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs,
+		  void *mc)
 {
 	int code, err;
 	if (!UPT_IS_USER(regs)) {
@@ -302,7 +319,8 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 	}
 }
 
-void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
+void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs,
+	   void *mc)
 {
 	do_IRQ(WINCH_IRQ, regs);
 }
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 79ea97d4797e..d4b3b6742ec8 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -12,6 +12,7 @@
 #include <linux/panic_notifier.h>
 #include <linux/seq_file.h>
 #include <linux/string.h>
+#include <linux/string_choices.h>
 #include <linux/utsname.h>
 #include <linux/sched.h>
 #include <linux/sched/task.h>
@@ -78,7 +79,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	seq_printf(m, "model name\t: UML\n");
 	seq_printf(m, "mode\t\t: skas\n");
 	seq_printf(m, "host\t\t: %s\n", host_info);
-	seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
+	seq_printf(m, "fpu\t\t: %s\n", str_yes_no(cpu_has(&boot_cpu_data, X86_FEATURE_FPU)));
 	seq_printf(m, "flags\t\t:");
 	for (i = 0; i < 32*NCAPINTS; i++)
 		if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
@@ -385,7 +386,6 @@ int __init linux_main(int argc, char **argv, char **envp)
 
 	high_physmem = uml_physmem + physmem_size;
 	end_iomem = high_physmem + iomem_size;
-	high_memory = (void *) end_iomem;
 
 	start_vm = VMALLOC_START;
 
@@ -419,7 +419,6 @@ void __init setup_arch(char **cmdline_p)
 
 	stack_protections((unsigned long) init_task.stack);
 	setup_physmem(uml_physmem, uml_reserved, physmem_size);
-	mem_total_pages(physmem_size, iomem_size);
 	uml_dtb_init();
 	read_initrd();
 
@@ -440,25 +439,24 @@ void __init arch_cpu_finalize_init(void)
 	os_check_bugs();
 }
 
-void apply_seal_endbr(s32 *start, s32 *end, struct module *mod)
+void apply_seal_endbr(s32 *start, s32 *end)
 {
 }
 
-void apply_retpolines(s32 *start, s32 *end, struct module *mod)
+void apply_retpolines(s32 *start, s32 *end)
 {
 }
 
-void apply_returns(s32 *start, s32 *end, struct module *mod)
+void apply_returns(s32 *start, s32 *end)
 {
 }
 
 void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
-		   s32 *start_cfi, s32 *end_cfi, struct module *mod)
+		   s32 *start_cfi, s32 *end_cfi)
 {
 }
 
-void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
-			struct module *mod)
+void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 {
 }