khusika
diff --git a/‎Documentation/devicetree/bindings/serial/8250.yaml
Lines changed: 1 addition & 1 deletion b/‎Documentation/devicetree/bindings/serial/8250.yaml
Lines changed: 1 addition & 1 deletion
diff --git a/‎Makefile
Lines changed: 1 addition & 1 deletion b/‎Makefile
Lines changed: 1 addition & 1 deletion
diff --git a/‎arch/arm/include/asm/ptrace.h
Lines changed: 3 additions & 2 deletions b/‎arch/arm/include/asm/ptrace.h
Lines changed: 3 additions & 2 deletions
diff --git a/‎arch/arm64/mm/mmu.c
Lines changed: 2 additions & 1 deletion b/‎arch/arm64/mm/mmu.c
Lines changed: 2 additions & 1 deletion
diff --git a/‎arch/s390/kernel/entry.S
Lines changed: 1 addition & 1 deletion b/‎arch/s390/kernel/entry.S
Lines changed: 1 addition & 1 deletion
diff --git a/‎arch/um/drivers/ubd_user.c
Lines changed: 1 addition & 1 deletion b/‎arch/um/drivers/ubd_user.c
Lines changed: 1 addition & 1 deletion
diff --git a/‎arch/um/include/asm/asm-prototypes.h
Lines changed: 5 additions & 0 deletions b/‎arch/um/include/asm/asm-prototypes.h
Lines changed: 5 additions & 0 deletions
diff --git a/‎arch/um/kernel/trap.c
Lines changed: 117 additions & 12 deletions b/‎arch/um/kernel/trap.c
Lines changed: 117 additions & 12 deletions
diff --git a/‎arch/x86/tools/insn_decoder_test.c
Lines changed: 2 additions & 3 deletions b/‎arch/x86/tools/insn_decoder_test.c
Lines changed: 2 additions & 3 deletions
diff --git a/‎arch/x86/um/asm/checksum.h
Lines changed: 3 additions & 0 deletions b/‎arch/x86/um/asm/checksum.h
Lines changed: 3 additions & 0 deletions
@@ -44,7 +44,7 @@ allOf:
                   - ns16550
                   - ns16550a
     then:
-      anyOf:
+      oneOf:
         - required: [ clock-frequency ]
         - required: [ clocks ]
 
 
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 6
 PATCHLEVEL = 1
-SUBLEVEL = 142
+SUBLEVEL = 143
 EXTRAVERSION =
 NAME = Curry Ramen
 
 
@@ -10,6 +10,7 @@
 #include <uapi/asm/ptrace.h>
 
 #ifndef __ASSEMBLY__
+#include <linux/bitfield.h>
 #include <linux/types.h>
 
 struct pt_regs {
@@ -35,8 +36,8 @@ struct svc_pt_regs {
 
 #ifndef CONFIG_CPU_V7M
 #define isa_mode(regs) \
-	((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \
-	 (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT))))
+	(FIELD_GET(PSR_J_BIT, (regs)->ARM_cpsr) << 1 | \
+	 FIELD_GET(PSR_T_BIT, (regs)->ARM_cpsr))
 #else
 #define isa_mode(regs) 1 /* Thumb */
 #endif
 
@@ -1503,7 +1503,8 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
 	next = addr;
 	end = addr + PUD_SIZE;
 	do {
-		pmd_free_pte_page(pmdp, next);
+		if (pmd_present(READ_ONCE(*pmdp)))
+			pmd_free_pte_page(pmdp, next);
 	} while (pmdp++, next += PMD_SIZE, next != end);
 
 	pud_clear(pudp);
 
@@ -690,7 +690,7 @@ ENTRY(stack_overflow)
 	stmg	%r0,%r7,__PT_R0(%r11)
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	mvc	__PT_R8(64,%r11),0(%r14)
-	stg	%r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
+	mvc	__PT_ORIG_GPR2(8,%r11),__LC_PGM_LAST_BREAK
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	lgr	%r2,%r11		# pass pointer to pt_regs
 	jg	kernel_stack_overflow
 
@@ -41,7 +41,7 @@ int start_io_thread(unsigned long sp, int *fd_out)
 	*fd_out = fds[1];
 
 	err = os_set_fd_block(*fd_out, 0);
-	err = os_set_fd_block(kernel_fd, 0);
+	err |= os_set_fd_block(kernel_fd, 0);
 	if (err) {
 		printk("start_io_thread - failed to set nonblocking I/O.\n");
 		goto out_close;
 
@@ -1 +1,6 @@
 #include <asm-generic/asm-prototypes.h>
+#include <asm/checksum.h>
+
+#ifdef CONFIG_UML_X86
+extern void cmpxchg8b_emu(void);
+#endif
@@ -17,6 +17,122 @@
 #include <os.h>
 #include <skas.h>
 
+/*
+ * NOTE: UML does not have exception tables. As such, this is almost a copy
+ * of the code in mm/memory.c, only adjusting the logic to simply check whether
+ * we are coming from the kernel instead of doing an additional lookup in the
+ * exception table.
+ * We can do this simplification because we never get here if the exception was
+ * fixable.
+ */
+static inline bool get_mmap_lock_carefully(struct mm_struct *mm, bool is_user)
+{
+	if (likely(mmap_read_trylock(mm)))
+		return true;
+
+	if (!is_user)
+		return false;
+
+	return !mmap_read_lock_killable(mm);
+}
+
+static inline bool mmap_upgrade_trylock(struct mm_struct *mm)
+{
+	/*
+	 * We don't have this operation yet.
+	 *
+	 * It should be easy enough to do: it's basically a
+	 *    atomic_long_try_cmpxchg_acquire()
+	 * from RWSEM_READER_BIAS -> RWSEM_WRITER_LOCKED, but
+	 * it also needs the proper lockdep magic etc.
+	 */
+	return false;
+}
+
+static inline bool upgrade_mmap_lock_carefully(struct mm_struct *mm, bool is_user)
+{
+	mmap_read_unlock(mm);
+	if (!is_user)
+		return false;
+
+	return !mmap_write_lock_killable(mm);
+}
+
+/*
+ * Helper for page fault handling.
+ *
+ * This is kind of equivalend to "mmap_read_lock()" followed
+ * by "find_extend_vma()", except it's a lot more careful about
+ * the locking (and will drop the lock on failure).
+ *
+ * For example, if we have a kernel bug that causes a page
+ * fault, we don't want to just use mmap_read_lock() to get
+ * the mm lock, because that would deadlock if the bug were
+ * to happen while we're holding the mm lock for writing.
+ *
+ * So this checks the exception tables on kernel faults in
+ * order to only do this all for instructions that are actually
+ * expected to fault.
+ *
+ * We can also actually take the mm lock for writing if we
+ * need to extend the vma, which helps the VM layer a lot.
+ */
+static struct vm_area_struct *
+um_lock_mm_and_find_vma(struct mm_struct *mm,
+			unsigned long addr, bool is_user)
+{
+	struct vm_area_struct *vma;
+
+	if (!get_mmap_lock_carefully(mm, is_user))
+		return NULL;
+
+	vma = find_vma(mm, addr);
+	if (likely(vma && (vma->vm_start <= addr)))
+		return vma;
+
+	/*
+	 * Well, dang. We might still be successful, but only
+	 * if we can extend a vma to do so.
+	 */
+	if (!vma || !(vma->vm_flags & VM_GROWSDOWN)) {
+		mmap_read_unlock(mm);
+		return NULL;
+	}
+
+	/*
+	 * We can try to upgrade the mmap lock atomically,
+	 * in which case we can continue to use the vma
+	 * we already looked up.
+	 *
+	 * Otherwise we'll have to drop the mmap lock and
+	 * re-take it, and also look up the vma again,
+	 * re-checking it.
+	 */
+	if (!mmap_upgrade_trylock(mm)) {
+		if (!upgrade_mmap_lock_carefully(mm, is_user))
+			return NULL;
+
+		vma = find_vma(mm, addr);
+		if (!vma)
+			goto fail;
+		if (vma->vm_start <= addr)
+			goto success;
+		if (!(vma->vm_flags & VM_GROWSDOWN))
+			goto fail;
+	}
+
+	if (expand_stack_locked(vma, addr))
+		goto fail;
+
+success:
+	mmap_write_downgrade(mm);
+	return vma;
+
+fail:
+	mmap_write_unlock(mm);
+	return NULL;
+}
+
 /*
  * Note this is constrained to return 0, -EFAULT, -EACCES, -ENOMEM by
  * segv().
@@ -43,21 +159,10 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	if (is_user)
 		flags |= FAULT_FLAG_USER;
 retry:
-	mmap_read_lock(mm);
-	vma = find_vma(mm, address);
-	if (!vma)
-		goto out;
-	if (vma->vm_start <= address)
-		goto good_area;
-	if (!(vma->vm_flags & VM_GROWSDOWN))
-		goto out;
-	if (is_user && !ARCH_IS_STACKGROW(address))
-		goto out;
-	vma = expand_stack(mm, address);
+	vma = um_lock_mm_and_find_vma(mm, address, is_user);
 	if (!vma)
 		goto out_nosemaphore;
 
-good_area:
 	*code_out = SEGV_ACCERR;
 	if (is_write) {
 		if (!(vma->vm_flags & VM_WRITE))
 
@@ -10,8 +10,7 @@
 #include <assert.h>
 #include <unistd.h>
 #include <stdarg.h>
-
-#define unlikely(cond) (cond)
+#include <linux/kallsyms.h>
 
 #include <asm/insn.h>
 #include <inat.c>
@@ -106,7 +105,7 @@ static void parse_args(int argc, char **argv)
 	}
 }
 
-#define BUFSIZE 256
+#define BUFSIZE (256 + KSYM_NAME_LEN)
 
 int main(int argc, char **argv)
 {
 
@@ -20,6 +20,9 @@
  */
 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
 
+/* Do not call this directly. Declared for export type visibility. */
+extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+
 /**
  * csum_fold - Fold and invert a 32bit checksum.
  * sum: 32bit unfolded sum
Original file line number	Diff line number	Diff line change
`@@ -10,8 +10,7 @@`
`10`	`10`	`#include <assert.h>`
`11`	`11`	`#include <unistd.h>`
`12`	`12`	`#include <stdarg.h>`
`13`		`-`
`14`		`-#define unlikely(cond) (cond)`
	`13`	`+#include <linux/kallsyms.h>`
`15`	`14`
`16`	`15`	`#include <asm/insn.h>`
`17`	`16`	`#include <inat.c>`
`@@ -106,7 +105,7 @@ static void parse_args(int argc, char **argv)`
`106`	`105`	`}`
`107`	`106`	`}`
`108`	`107`
`109`		`-#define BUFSIZE 256`
	`108`	`+#define BUFSIZE (256 + KSYM_NAME_LEN)`
`110`	`109`
`111`	`110`	`int main(int argc, char **argv)`
`112`	`111`	`{`