From 7b6e92664130232b245a980b6869c4fcae934fad Mon Sep 17 00:00:00 2001
From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Wed, 31 Jan 2018 20:28:56 +0100
Subject: [PATCH] Handle very special __ARM_NR_-prefixed syscalls

* linux/aarch64/nr_prefix.c: New file.
* linux/arm/nr_prefix.c: Likewise.
* linux/nr_prefix.c: Likewise.
* Makefile.am (EXTRA_DIST): Add them.
* printsiginfo.c: Include nr_prefix.c
(print_si_info): Use nr_prefix.
---
 Makefile.am               |  3 +++
 linux/aarch64/nr_prefix.c |  1 +
 linux/arm/nr_prefix.c     | 12 ++++++++++++
 linux/nr_prefix.c         | 11 +++++++++++
 printsiginfo.c            |  5 ++++-
 5 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 linux/aarch64/nr_prefix.c
 create mode 100644 linux/arm/nr_prefix.c
 create mode 100644 linux/nr_prefix.c

diff --git a/Makefile.am b/Makefile.am
index 137063d6..5cf2c9bf 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -404,6 +404,7 @@ EXTRA_DIST =				\
 	linux/aarch64/ioctls_arch1.h	\
 	linux/aarch64/ioctls_inc0.h	\
 	linux/aarch64/ioctls_inc1.h	\
+	linux/aarch64/nr_prefix.c	\
 	linux/aarch64/set_error.c	\
 	linux/aarch64/set_scno.c	\
 	linux/aarch64/shuffle_scno.c	\
@@ -453,6 +454,7 @@ EXTRA_DIST =				\
 	linux/arm/get_syscall_args.c	\
 	linux/arm/ioctls_arch0.h	\
 	linux/arm/ioctls_inc0.h		\
+	linux/arm/nr_prefix.c		\
 	linux/arm/set_error.c		\
 	linux/arm/set_scno.c		\
 	linux/arm/shuffle_scno.c	\
@@ -611,6 +613,7 @@ EXTRA_DIST =				\
 	linux/nios2/set_error.c		\
 	linux/nios2/set_scno.c		\
 	linux/nios2/syscallent.h	\
+	linux/nr_prefix.c		\
 	linux/or1k/arch_regs.c		\
 	linux/or1k/arch_regs.h		\
 	linux/or1k/arch_rt_sigframe.c	\
diff --git a/linux/aarch64/nr_prefix.c b/linux/aarch64/nr_prefix.c
new file mode 100644
index 00000000..49fe77ae
--- /dev/null
+++ b/linux/aarch64/nr_prefix.c
@@ -0,0 +1 @@
+#include "../arm/nr_prefix.c"
diff --git a/linux/arm/nr_prefix.c b/linux/arm/nr_prefix.c
new file mode 100644
index 00000000..99f571ff
--- /dev/null
+++ b/linux/arm/nr_prefix.c
@@ -0,0 +1,12 @@
+static inline const char *
+nr_prefix(kernel_ulong_t scno)
+{
+	/*
+	 * For now, the set of syscalls that are shuffled is equivalent to the
+	 * set of syscalls that have __ARM_NR_ prefix.
+	 */
+	if (shuffle_scno(scno) != scno)
+		return "__ARM_NR_";
+	else
+		return "__NR_";
+}
diff --git a/linux/nr_prefix.c b/linux/nr_prefix.c
new file mode 100644
index 00000000..f22814f4
--- /dev/null
+++ b/linux/nr_prefix.c
@@ -0,0 +1,11 @@
+/**
+ * Returns prefix for a syscall constant literal.  It is has to be that way
+ * thanks to ARM that decided to prefix their special system calls like sys32
+ * and sys26 with __ARM_NR_* prefix instead of __NR_*, so we can't simply print
+ * "__NR_".
+ */
+static inline const char *
+nr_prefix(kernel_ulong_t scno)
+{
+	return "__NR_";
+}
diff --git a/printsiginfo.c b/printsiginfo.c
index c1f826c9..d5ff8757 100644
--- a/printsiginfo.c
+++ b/printsiginfo.c
@@ -42,6 +42,8 @@
 
 #include MPERS_DEFS
 
+#include "nr_prefix.c"
+
 #ifndef IN_MPERS
 #include "printsiginfo.h"
 #endif
@@ -214,7 +216,8 @@ print_si_info(const siginfo_t *sip)
 			printaddr(ptr_to_kulong(sip->si_call_addr));
 			tprints(", si_syscall=");
 			if (scname)
-				tprintf("__NR_%s", scname);
+				tprintf("%s%s",
+					nr_prefix(sip->si_syscall), scname);
 			else
 				tprintf("%u", (unsigned) sip->si_syscall);
 			tprints(", si_arch=");
-- 
2.40.0