Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 615 insertions, 0 deletions

diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
new file mode 100644
index 0000000000..f93972a257
--- /dev/null
+++ b/arch/um/kernel/skas/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+#
+
+obj-y := clone.o mmu.o process.o syscall.o uaccess.o
+
+# clone.o is in the stub, so it can't be built with profiling
+# GCC hardened also auto-enables -fpic, but we need %ebx so it can't work ->
+# disable it
+
+CFLAGS_clone.o := $(CFLAGS_NO_HARDENING)
+UNPROFILE_OBJS := clone.o
+
+KCOV_INSTRUMENT := n
+
+include $(srctree)/arch/um/scripts/Makefile.rules
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
new file mode 100644
index 0000000000..62435187dd
--- /dev/null
+++ b/arch/um/kernel/skas/clone.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <signal.h>
+#include <sched.h>
+#include <asm/unistd.h>
+#include <sys/time.h>
+#include <as-layout.h>
+#include <ptrace_user.h>
+#include <stub-data.h>
+#include <sysdep/stub.h>
+
+/*
+ * This is in a separate file because it needs to be compiled with any
+ * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
+ *
+ * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
+ * on some systems.
+ */
+
+void __attribute__ ((__section__ (".__syscall_stub")))
+stub_clone_handler(void)
+{
+	struct stub_data *data = get_stub_data();
+	long err;
+
+	err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
+			    (unsigned long)data +
+				STUB_DATA_PAGES * UM_KERN_PAGE_SIZE / 2);
+	if (err) {
+		data->parent_err = err;
+		goto done;
+	}
+
+	err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
+	if (err) {
+		data->child_err = err;
+		goto done;
+	}
+
+	remap_stack_and_trap();
+
+ done:
+	trap_myself();
+}
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
new file mode 100644
index 0000000000..656fe16c9b
--- /dev/null
+++ b/arch/um/kernel/skas/mmu.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <as-layout.h>
+#include <os.h>
+#include <skas.h>
+
+int init_new_context(struct task_struct *task, struct mm_struct *mm)
+{
+ 	struct mm_context *from_mm = NULL;
+	struct mm_context *to_mm = &mm->context;
+	unsigned long stack = 0;
+	int ret = -ENOMEM;
+
+	stack = __get_free_pages(GFP_KERNEL | __GFP_ZERO, ilog2(STUB_DATA_PAGES));
+	if (stack == 0)
+		goto out;
+
+	to_mm->id.stack = stack;
+	if (current->mm != NULL && current->mm != &init_mm)
+		from_mm = &current->mm->context;
+
+	block_signals_trace();
+	if (from_mm)
+		to_mm->id.u.pid = copy_context_skas0(stack,
+						     from_mm->id.u.pid);
+	else to_mm->id.u.pid = start_userspace(stack);
+	unblock_signals_trace();
+
+	if (to_mm->id.u.pid < 0) {
+		ret = to_mm->id.u.pid;
+		goto out_free;
+	}
+
+	ret = init_new_ldt(to_mm, from_mm);
+	if (ret < 0) {
+		printk(KERN_ERR "init_new_context_skas - init_ldt"
+		       " failed, errno = %d\n", ret);
+		goto out_free;
+	}
+
+	return 0;
+
+ out_free:
+	if (to_mm->id.stack != 0)
+		free_pages(to_mm->id.stack, ilog2(STUB_DATA_PAGES));
+ out:
+	return ret;
+}
+
+void destroy_context(struct mm_struct *mm)
+{
+	struct mm_context *mmu = &mm->context;
+
+	/*
+	 * If init_new_context wasn't called, this will be
+	 * zero, resulting in a kill(0), which will result in the
+	 * whole UML suddenly dying.  Also, cover negative and
+	 * 1 cases, since they shouldn't happen either.
+	 */
+	if (mmu->id.u.pid < 2) {
+		printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+		       mmu->id.u.pid);
+		return;
+	}
+	os_kill_ptraced_process(mmu->id.u.pid, 1);
+
+	free_pages(mmu->id.stack, ilog2(STUB_DATA_PAGES));
+	free_ldt(mmu);
+}
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
new file mode 100644
index 0000000000..f2ac134c97
--- /dev/null
+++ b/arch/um/kernel/skas/process.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/init.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/task.h>
+
+#include <as-layout.h>
+#include <kern.h>
+#include <os.h>
+#include <skas.h>
+
+extern void start_kernel(void);
+
+static int __init start_kernel_proc(void *unused)
+{
+	int pid;
+
+	block_signals_trace();
+	pid = os_getpid();
+
+	cpu_tasks[0].pid = pid;
+	cpu_tasks[0].task = current;
+
+	start_kernel();
+	return 0;
+}
+
+extern int userspace_pid[];
+
+extern char cpu0_irqstack[];
+
+int __init start_uml(void)
+{
+	stack_protections((unsigned long) &cpu0_irqstack);
+	set_sigstack(cpu0_irqstack, THREAD_SIZE);
+
+	init_new_thread_signals();
+
+	init_task.thread.request.u.thread.proc = start_kernel_proc;
+	init_task.thread.request.u.thread.arg = NULL;
+	return start_idle_thread(task_stack_page(&init_task),
+				 &init_task.thread.switch_buf);
+}
+
+unsigned long current_stub_stack(void)
+{
+	if (current->mm == NULL)
+		return 0;
+
+	return current->mm->context.id.stack;
+}
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
new file mode 100644
index 0000000000..9ee19e566d
--- /dev/null
+++ b/arch/um/kernel/skas/syscall.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/seccomp.h>
+#include <kern_util.h>
+#include <sysdep/ptrace.h>
+#include <sysdep/ptrace_user.h>
+#include <sysdep/syscalls.h>
+#include <linux/time-internal.h>
+#include <asm/unistd.h>
+
+void handle_syscall(struct uml_pt_regs *r)
+{
+	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
+	int syscall;
+
+	/*
+	 * If we have infinite CPU resources, then make every syscall also a
+	 * preemption point, since we don't have any other preemption in this
+	 * case, and kernel threads would basically never run until userspace
+	 * went to sleep, even if said userspace interacts with the kernel in
+	 * various ways.
+	 */
+	if (time_travel_mode == TT_MODE_INFCPU ||
+	    time_travel_mode == TT_MODE_EXTERNAL)
+		schedule();
+
+	/* Initialize the syscall number and default return value. */
+	UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
+	PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS);
+
+	if (syscall_trace_enter(regs))
+		goto out;
+
+	/* Do the seccomp check after ptrace; failures should be fast. */
+	if (secure_computing() == -1)
+		goto out;
+
+	syscall = UPT_SYSCALL_NR(r);
+	if (syscall >= 0 && syscall < __NR_syscalls)
+		PT_REGS_SET_SYSCALL_RETURN(regs,
+				EXECUTE_SYSCALL(syscall, regs));
+
+out:
+	syscall_trace_leave(regs);
+}
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
new file mode 100644
index 0000000000..aaee96f071
--- /dev/null
+++ b/arch/um/kernel/skas/uaccess.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+#include <asm/page.h>
+#include <kern_util.h>
+#include <asm/futex.h>
+#include <os.h>
+
+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	if (mm == NULL)
+		return NULL;
+
+	pgd = pgd_offset(mm, addr);
+	if (!pgd_present(*pgd))
+		return NULL;
+
+	p4d = p4d_offset(pgd, addr);
+	if (!p4d_present(*p4d))
+		return NULL;
+
+	pud = pud_offset(p4d, addr);
+	if (!pud_present(*pud))
+		return NULL;
+
+	pmd = pmd_offset(pud, addr);
+	if (!pmd_present(*pmd))
+		return NULL;
+
+	return pte_offset_kernel(pmd, addr);
+}
+
+static pte_t *maybe_map(unsigned long virt, int is_write)
+{
+	pte_t *pte = virt_to_pte(current->mm, virt);
+	int err, dummy_code;
+
+	if ((pte == NULL) || !pte_present(*pte) ||
+	    (is_write && !pte_write(*pte))) {
+		err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
+		if (err)
+			return NULL;
+		pte = virt_to_pte(current->mm, virt);
+	}
+	if (!pte_present(*pte))
+		pte = NULL;
+
+	return pte;
+}
+
+static int do_op_one_page(unsigned long addr, int len, int is_write,
+		 int (*op)(unsigned long addr, int len, void *arg), void *arg)
+{
+	struct page *page;
+	pte_t *pte;
+	int n;
+
+	pte = maybe_map(addr, is_write);
+	if (pte == NULL)
+		return -1;
+
+	page = pte_page(*pte);
+#ifdef CONFIG_64BIT
+	pagefault_disable();
+	addr = (unsigned long) page_address(page) +
+		(addr & ~PAGE_MASK);
+#else
+	addr = (unsigned long) kmap_atomic(page) +
+		(addr & ~PAGE_MASK);
+#endif
+	n = (*op)(addr, len, arg);
+
+#ifdef CONFIG_64BIT
+	pagefault_enable();
+#else
+	kunmap_atomic((void *)addr);
+#endif
+
+	return n;
+}
+
+static long buffer_op(unsigned long addr, int len, int is_write,
+		      int (*op)(unsigned long, int, void *), void *arg)
+{
+	long size, remain, n;
+
+	size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
+	remain = len;
+
+	n = do_op_one_page(addr, size, is_write, op, arg);
+	if (n != 0) {
+		remain = (n < 0 ? remain : 0);
+		goto out;
+	}
+
+	addr += size;
+	remain -= size;
+	if (remain == 0)
+		goto out;
+
+	while (addr < ((addr + remain) & PAGE_MASK)) {
+		n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);
+		if (n != 0) {
+			remain = (n < 0 ? remain : 0);
+			goto out;
+		}
+
+		addr += PAGE_SIZE;
+		remain -= PAGE_SIZE;
+	}
+	if (remain == 0)
+		goto out;
+
+	n = do_op_one_page(addr, remain, is_write, op, arg);
+	if (n != 0) {
+		remain = (n < 0 ? remain : 0);
+		goto out;
+	}
+
+	return 0;
+ out:
+	return remain;
+}
+
+static int copy_chunk_from_user(unsigned long from, int len, void *arg)
+{
+	unsigned long *to_ptr = arg, to = *to_ptr;
+
+	memcpy((void *) to, (void *) from, len);
+	*to_ptr += len;
+	return 0;
+}
+
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	return buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to);
+}
+EXPORT_SYMBOL(raw_copy_from_user);
+
+static int copy_chunk_to_user(unsigned long to, int len, void *arg)
+{
+	unsigned long *from_ptr = arg, from = *from_ptr;
+
+	memcpy((void *) to, (void *) from, len);
+	*from_ptr += len;
+	return 0;
+}
+
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	return buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from);
+}
+EXPORT_SYMBOL(raw_copy_to_user);
+
+static int strncpy_chunk_from_user(unsigned long from, int len, void *arg)
+{
+	char **to_ptr = arg, *to = *to_ptr;
+	int n;
+
+	strncpy(to, (void *) from, len);
+	n = strnlen(to, len);
+	*to_ptr += n;
+
+	if (n < len)
+	        return 1;
+	return 0;
+}
+
+long strncpy_from_user(char *dst, const char __user *src, long count)
+{
+	long n;
+	char *ptr = dst;
+
+	if (!access_ok(src, 1))
+		return -EFAULT;
+	n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
+		      &ptr);
+	if (n != 0)
+		return -EFAULT;
+	return strnlen(dst, count);
+}
+EXPORT_SYMBOL(strncpy_from_user);
+
+static int clear_chunk(unsigned long addr, int len, void *unused)
+{
+	memset((void *) addr, 0, len);
+	return 0;
+}
+
+unsigned long __clear_user(void __user *mem, unsigned long len)
+{
+	return buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL);
+}
+EXPORT_SYMBOL(__clear_user);
+
+static int strnlen_chunk(unsigned long str, int len, void *arg)
+{
+	int *len_ptr = arg, n;
+
+	n = strnlen((void *) str, len);
+	*len_ptr += n;
+
+	if (n < len)
+		return 1;
+	return 0;
+}
+
+long strnlen_user(const char __user *str, long len)
+{
+	int count = 0, n;
+
+	if (!access_ok(str, 1))
+		return -EFAULT;
+	n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
+	if (n == 0)
+		return count + 1;
+	return 0;
+}
+EXPORT_SYMBOL(strnlen_user);
+
+/**
+ * arch_futex_atomic_op_inuser() - Atomic arithmetic operation with constant
+ *			  argument and comparison of the previous
+ *			  futex value with another constant.
+ *
+ * @encoded_op:	encoded operation to execute
+ * @uaddr:	pointer to user space address
+ *
+ * Return:
+ * 0 - On success
+ * -EFAULT - User access resulted in a page fault
+ * -EAGAIN - Atomic operation was unable to complete due to contention
+ * -ENOSYS - Operation not supported
+ */
+
+int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
+{
+	int oldval, ret;
+	struct page *page;
+	unsigned long addr = (unsigned long) uaddr;
+	pte_t *pte;
+
+	ret = -EFAULT;
+	if (!access_ok(uaddr, sizeof(*uaddr)))
+		return -EFAULT;
+	preempt_disable();
+	pte = maybe_map(addr, 1);
+	if (pte == NULL)
+		goto out_inuser;
+
+	page = pte_page(*pte);
+#ifdef CONFIG_64BIT
+	pagefault_disable();
+	addr = (unsigned long) page_address(page) +
+			(((unsigned long) addr) & ~PAGE_MASK);
+#else
+	addr = (unsigned long) kmap_atomic(page) +
+		((unsigned long) addr & ~PAGE_MASK);
+#endif
+	uaddr = (u32 *) addr;
+	oldval = *uaddr;
+
+	ret = 0;
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		*uaddr = oparg;
+		break;
+	case FUTEX_OP_ADD:
+		*uaddr += oparg;
+		break;
+	case FUTEX_OP_OR:
+		*uaddr |= oparg;
+		break;
+	case FUTEX_OP_ANDN:
+		*uaddr &= ~oparg;
+		break;
+	case FUTEX_OP_XOR:
+		*uaddr ^= oparg;
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+#ifdef CONFIG_64BIT
+	pagefault_enable();
+#else
+	kunmap_atomic((void *)addr);
+#endif
+
+out_inuser:
+	preempt_enable();
+
+	if (ret == 0)
+		*oval = oldval;
+
+	return ret;
+}
+EXPORT_SYMBOL(arch_futex_atomic_op_inuser);
+
+/**
+ * futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the
+ *				uaddr with newval if the current value is
+ *				oldval.
+ * @uval:	pointer to store content of @uaddr
+ * @uaddr:	pointer to user space address
+ * @oldval:	old value
+ * @newval:	new value to store to @uaddr
+ *
+ * Return:
+ * 0 - On success
+ * -EFAULT - User access resulted in a page fault
+ * -EAGAIN - Atomic operation was unable to complete due to contention
+ */
+
+int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
+{
+	struct page *page;
+	pte_t *pte;
+	int ret = -EFAULT;
+
+	if (!access_ok(uaddr, sizeof(*uaddr)))
+		return -EFAULT;
+
+	preempt_disable();
+	pte = maybe_map((unsigned long) uaddr, 1);
+	if (pte == NULL)
+		goto out_inatomic;
+
+	page = pte_page(*pte);
+#ifdef CONFIG_64BIT
+	pagefault_disable();
+	uaddr = page_address(page) + (((unsigned long) uaddr) & ~PAGE_MASK);
+#else
+	uaddr = kmap_atomic(page) + ((unsigned long) uaddr & ~PAGE_MASK);
+#endif
+
+	*uval = *uaddr;
+
+	ret = cmpxchg(uaddr, oldval, newval);
+
+#ifdef CONFIG_64BIT
+	pagefault_enable();
+#else
+	kunmap_atomic(uaddr);
+#endif
+	ret = 0;
+
+out_inatomic:
+	preempt_enable();
+	return ret;
+}
+EXPORT_SYMBOL(futex_atomic_cmpxchg_inatomic);