perf: Fix build on rv32

Signed-off-by: Khem Raj <raj.khem@gmail.com>

recipes-kernel/linux/files/0001-perf-Alias-SYS_futex-with-SYS_futex_time64-on-32-bit.patch

@@ -0,0 +1,44 @@
+From 4965d191806c9a28bffbb157228bf42270b0008e Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Mon, 16 Nov 2020 11:03:31 -0800
+Subject: [PATCH] perf: Alias SYS_futex with SYS_futex_time64 on 32-bit arches
+ with 64bit time_t
+
+glibc does not define SYS_futex for 32bit architectures using 64bit
+time_t e.g. riscv32, therefore perf fails to compile as it does not find
+SYS_futex in C library headers, define it to SYS_futex_time64 when it
+exists
+
+Upstream-Status: Pending
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ tools/perf/bench/futex.h | 13 +++++++++++++
+ 1 file changed, 13 insertions(+)
+
+diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
+index 31b53cc7d5bc..33f3f3230ae1 100644
+--- a/tools/perf/bench/futex.h
++++ b/tools/perf/bench/futex.h
+@@ -13,6 +13,19 @@
+ #include <sys/types.h>
+ #include <linux/futex.h>
+ 
++/**
++ * SYS_futex is expected from system C library,
++ * in glibc (/usr/include/bits/syscall.h defines it in terms of of NR_futex)
++ * some newer 32bit architectures e.g. RISCV32 is using 64bit time_t from
++ * get go unlike other 32bit architectures in glibc, therefore it wont have
++ * NR_futex defined but just NR_futex_time64 this aliases it to NR_futex
++ * so that SYS_futex is then defined for rv32
++*/
++
++#if !defined(SYS_futex) && defined(SYS_futex_time64)
++#define SYS_futex SYS_futex_time64
++#endif
++
+ /**
+  * futex() - SYS_futex syscall wrapper
+  * @uaddr:	address of first futex
+-- 
+2.29.2
+

recipes-kernel/linux/linux-yocto_5.%.bbappend

@@ -1 +1,5 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
 COMPATIBLE_MACHINE_append = "|qemuriscv32"
+
+SRC_URI_append_riscv32 = " file://0001-perf-Alias-SYS_futex-with-SYS_futex_time64-on-32-bit.patch"