Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 6de1fd3..332eb35 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -37,8 +37,10 @@
 	unsigned short __esh;
 	unsigned short fs;
 	unsigned short __fsh;
+	/* On interrupt, gs and __gsh store the vector number. */
 	unsigned short gs;
 	unsigned short __gsh;
+	/* On interrupt, this is the error code. */
 	unsigned long orig_ax;
 	unsigned long ip;
 	unsigned short cs;
@@ -96,12 +98,10 @@
 struct task_struct;
 
 extern unsigned long profile_pc(struct pt_regs *regs);
-#define profile_pc profile_pc
 
 extern unsigned long
 convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
-extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
-			 int error_code, int si_code);
+extern void send_sigtrap(struct pt_regs *regs, int error_code, int si_code);
 
 
 static inline unsigned long regs_return_value(struct pt_regs *regs)
@@ -144,7 +144,7 @@
 static inline bool user_64bit_mode(struct pt_regs *regs)
 {
 #ifdef CONFIG_X86_64
-#ifndef CONFIG_PARAVIRT
+#ifndef CONFIG_PARAVIRT_XXL
 	/*
 	 * On non-paravirt systems, this is the only long mode CPL 3
 	 * selector.  We do not allow long mode selectors in the LDT.
@@ -164,20 +164,37 @@
 #define compat_user_stack_pointer()	current_pt_regs()->sp
 #endif
 
-#ifdef CONFIG_X86_32
-extern unsigned long kernel_stack_pointer(struct pt_regs *regs);
-#else
 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 {
 	return regs->sp;
 }
-#endif
 
-#define GET_IP(regs) ((regs)->ip)
-#define GET_FP(regs) ((regs)->bp)
-#define GET_USP(regs) ((regs)->sp)
+static inline unsigned long instruction_pointer(struct pt_regs *regs)
+{
+	return regs->ip;
+}
 
-#include <asm-generic/ptrace.h>
+static inline void instruction_pointer_set(struct pt_regs *regs,
+		unsigned long val)
+{
+	regs->ip = val;
+}
+
+static inline unsigned long frame_pointer(struct pt_regs *regs)
+{
+	return regs->bp;
+}
+
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+	return regs->sp;
+}
+
+static inline void user_stack_pointer_set(struct pt_regs *regs,
+		unsigned long val)
+{
+	regs->sp = val;
+}
 
 /* Query offset/name of register from its name/offset */
 extern int regs_query_register_offset(const char *name);
@@ -199,14 +216,6 @@
 	if (unlikely(offset > MAX_REG_OFFSET))
 		return 0;
 #ifdef CONFIG_X86_32
-	/*
-	 * Traps from the kernel do not save sp and ss.
-	 * Use the helper function to retrieve sp.
-	 */
-	if (offset == offsetof(struct pt_regs, sp) &&
-	    regs->cs == __KERNEL_CS)
-		return kernel_stack_pointer(regs);
-
 	/* The selector fields are 16-bit. */
 	if (offset == offsetof(struct pt_regs, cs) ||
 	    offset == offsetof(struct pt_regs, ss) ||
@@ -232,28 +241,93 @@
 static inline int regs_within_kernel_stack(struct pt_regs *regs,
 					   unsigned long addr)
 {
-	return ((addr & ~(THREAD_SIZE - 1))  ==
-		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+	return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1)));
 }
 
 /**
+ * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
+ * @regs:	pt_regs which contains kernel stack pointer.
+ * @n:		stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
+ * kernel stack which is specified by @regs. If the @n th entry is NOT in
+ * the kernel stack, this returns NULL.
+ */
+static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)regs->sp;
+
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return addr;
+	else
+		return NULL;
+}
+
+/* To avoid include hell, we can't include uaccess.h */
+extern long probe_kernel_read(void *dst, const void *src, size_t size);
+
+/**
  * regs_get_kernel_stack_nth() - get Nth entry of the stack
  * @regs:	pt_regs which contains kernel stack pointer.
  * @n:		stack entry number.
  *
  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
- * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack
  * this returns 0.
  */
 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 						      unsigned int n)
 {
-	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
-	addr += n;
-	if (regs_within_kernel_stack(regs, (unsigned long)addr))
-		return *addr;
-	else
-		return 0;
+	unsigned long *addr;
+	unsigned long val;
+	long ret;
+
+	addr = regs_get_kernel_stack_nth_addr(regs, n);
+	if (addr) {
+		ret = probe_kernel_read(&val, addr, sizeof(val));
+		if (!ret)
+			return val;
+	}
+	return 0;
+}
+
+/**
+ * regs_get_kernel_argument() - get Nth function argument in kernel
+ * @regs:	pt_regs of that context
+ * @n:		function argument number (start from 0)
+ *
+ * regs_get_argument() returns @n th argument of the function call.
+ * Note that this chooses most probably assignment, in some case
+ * it can be incorrect.
+ * This is expected to be called from kprobes or ftrace with regs
+ * where the top of stack is the return address.
+ */
+static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
+						     unsigned int n)
+{
+	static const unsigned int argument_offs[] = {
+#ifdef __i386__
+		offsetof(struct pt_regs, ax),
+		offsetof(struct pt_regs, cx),
+		offsetof(struct pt_regs, dx),
+#define NR_REG_ARGUMENTS 3
+#else
+		offsetof(struct pt_regs, di),
+		offsetof(struct pt_regs, si),
+		offsetof(struct pt_regs, dx),
+		offsetof(struct pt_regs, cx),
+		offsetof(struct pt_regs, r8),
+		offsetof(struct pt_regs, r9),
+#define NR_REG_ARGUMENTS 6
+#endif
+	};
+
+	if (n >= NR_REG_ARGUMENTS) {
+		n -= NR_REG_ARGUMENTS - 1;
+		return regs_get_kernel_stack_nth(regs, n);
+	} else
+		return regs_get_register(regs, argument_offs[n]);
 }
 
 #define arch_has_single_step()	(1)
@@ -263,7 +337,7 @@
 #define arch_has_block_step()	(boot_cpu_data.x86 >= 6)
 #endif
 
-#define ARCH_HAS_USER_SINGLE_STEP_INFO
+#define ARCH_HAS_USER_SINGLE_STEP_REPORT
 
 /*
  * When hitting ptrace_stop(), we cannot return using SYSRET because