From 86faae616ce32bb768441087605fa40cb93091b8 Mon Sep 17 00:00:00 2001
From: Prakash Surya <prakash.surya@delphix.com>
Date: Thu, 13 Feb 2020 07:35:06 -0800
Subject: [PATCH] Disable "-fipa-sra" when using "--enable-debuginfo" (#127)

To better enable dynamic tracing tools (e.g. "bpftrace") this change
disables the "-fipa-sra" compilation optimization. This way, function
signatures are not changed by the compiler, which allows us to better
attach to kprobes and kretprobes with dynamic tracing tools. Otherwise,
the compiler may append ".isra" to the function name, and possibly
change the function arguments as well.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #9921
---
 config/zfs-build.m4 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/config/zfs-build.m4 b/config/zfs-build.m4
index f0c2066af4a2..34bacac8369f 100644
--- a/config/zfs-build.m4
+++ b/config/zfs-build.m4
@@ -59,9 +59,9 @@ AC_DEFUN([ZFS_AC_DEBUG], [
 ])
 
 AC_DEFUN([ZFS_AC_DEBUGINFO_ENABLE], [
-	DEBUG_CFLAGS="$DEBUG_CFLAGS -g -fno-inline"
+	DEBUG_CFLAGS="$DEBUG_CFLAGS -g -fno-inline -fno-ipa-sra"
 
-	KERNEL_DEBUG_CFLAGS="$KERNEL_DEBUG_CFLAGS -fno-inline"
+	KERNEL_DEBUG_CFLAGS="$KERNEL_DEBUG_CFLAGS -fno-inline -fno-ipa-sra"
 	KERNEL_MAKE="$KERNEL_MAKE CONFIG_DEBUG_INFO=y"
 
 	DEBUGINFO_ZFS="_with_debuginfo"