--- zzzz-none-000/linux-3.10.107/arch/arm/kernel/signal.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/arm/kernel/signal.c	2021-02-04 17:41:59.000000000 +0000
@@ -13,6 +13,7 @@
 #include <linux/personality.h>
 #include <linux/uaccess.h>
 #include <linux/tracehook.h>
+#include <linux/uprobes.h>
 
 #include <asm/elf.h>
 #include <asm/cacheflush.h>
@@ -21,29 +22,7 @@
 #include <asm/unistd.h>
 #include <asm/vfp.h>
 
-/*
- * For ARM syscalls, we encode the syscall number into the instruction.
- */
-#define SWI_SYS_SIGRETURN	(0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
-#define SWI_SYS_RT_SIGRETURN	(0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
-
-/*
- * With EABI, the syscall number has to be loaded into r7.
- */
-#define MOV_R7_NR_SIGRETURN	(0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
-#define MOV_R7_NR_RT_SIGRETURN	(0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
-
-/*
- * For Thumb syscalls, we pass the syscall number via r7.  We therefore
- * need two 16-bit instructions.
- */
-#define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
-#define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
-
-static const unsigned long sigreturn_codes[7] = {
-	MOV_R7_NR_SIGRETURN,    SWI_SYS_SIGRETURN,    SWI_THUMB_SIGRETURN,
-	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
-};
+extern const unsigned long sigreturn_codes[7];
 
 static unsigned long signal_return_offset;
 
@@ -212,7 +191,7 @@
 	struct sigframe __user *frame;
 
 	/* Always make any pending restarted system calls return -EINTR */
-	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+	current->restart_block.fn = do_no_restart_syscall;
 
 	/*
 	 * Since we stacked the signal on a 64-bit boundary,
@@ -242,7 +221,7 @@
 	struct rt_sigframe __user *frame;
 
 	/* Always make any pending restarted system calls return -EINTR */
-	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+	current->restart_block.fn = do_no_restart_syscall;
 
 	/*
 	 * Since we stacked the signal on a 64-bit boundary,
@@ -339,17 +318,6 @@
 	return frame;
 }
 
-/*
- * translate the signal
- */
-static inline int map_sig(int sig)
-{
-	struct thread_info *thread = current_thread_info();
-	if (sig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
-		sig = thread->exec_domain->signal_invmap[sig];
-	return sig;
-}
-
 static int
 setup_return(struct pt_regs *regs, struct ksignal *ksig,
 	     unsigned long __user *rc, void __user *frame)
@@ -375,12 +343,21 @@
 		 */
 		thumb = handler & 1;
 
+		/*
+		 * Clear the If-Then Thumb-2 execution state.  ARM spec
+		 * requires this to be all 000s in ARM mode.  Snapdragon
+		 * S4/Krait misbehaves on a Thumb=>ARM signal transition
+		 * without this.
+		 *
+		 * We must do this whenever we are running on a Thumb-2
+		 * capable CPU, which includes ARMv6T2.  However, we elect
+		 * to always do this to simplify the code; this field is
+		 * marked UNK/SBZP for older architectures.
+		 */
+		cpsr &= ~PSR_IT_MASK;
+
 		if (thumb) {
 			cpsr |= PSR_T_BIT;
-#if __LINUX_ARM_ARCH__ >= 7
-			/* clear the If-Then Thumb-2 execution state */
-			cpsr &= ~PSR_IT_MASK;
-#endif
 		} else
 			cpsr &= ~PSR_T_BIT;
 	}
@@ -394,6 +371,10 @@
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 			idx += 3;
 
+		/*
+		 * Put the sigreturn code on the stack no matter which return
+		 * mechanism we use in order to remain ABI compliant
+		 */
 		if (__put_user(sigreturn_codes[idx],   rc) ||
 		    __put_user(sigreturn_codes[idx+1], rc+1))
 			return 1;
@@ -401,6 +382,7 @@
 #ifdef CONFIG_MMU
 		if (cpsr & MODE32_BIT) {
 			struct mm_struct *mm = current->mm;
+
 			/*
 			 * 32-bit code can use the signal return page
 			 * except when the MPU has protected the vectors
@@ -422,7 +404,7 @@
 		}
 	}
 
-	regs->ARM_r0 = map_sig(ksig->sig);
+	regs->ARM_r0 = ksig->sig;
 	regs->ARM_sp = (unsigned long)frame;
 	regs->ARM_lr = retcode;
 	regs->ARM_pc = handler;
@@ -583,6 +565,12 @@
 asmlinkage int
 do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
+	/*
+	 * The assembly code enters us with IRQs off, but it hasn't
+	 * informed the tracing code of that for efficiency reasons.
+	 * Update the trace code with the current status.
+	 */
+	trace_hardirqs_off();
 	do {
 		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
 			schedule();
@@ -601,6 +589,8 @@
 					return restart;
 				}
 				syscall = 0;
+			} else if (thread_flags & _TIF_UPROBE) {
+				uprobe_notify_resume(regs);
 			} else {
 				clear_thread_flag(TIF_NOTIFY_RESUME);
 				tracehook_notify_resume(regs);