From d504ea731ffc58dcdfa91ddc2c9d6aadfa9bcb37 Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?=
 <jeremie.galarneau@efficios.com>
Date: Tue, 8 Nov 2022 17:13:37 -0500
Subject: [PATCH] Fix: syscalls-extractor: kallsyms_lookup_name no longer
 available
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Since v5.7, kallsyms_lookup_name is no longer available.

In order to re-use the kallsyms wrapper, it is simpler to move the
syscalls extractor module to the `src` directory and gate its
compilation behind a new config option, CONFIG_LTTNG_SYSCALLS_EXTRACTOR.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I55d878dce55827d61035693aaf5865af3c4e775f
---
 Makefile                                                 | 7 +++++++
 src/Kbuild                                               | 2 ++
 src/Kconfig                                              | 9 +++++++++
 .../lttng-syscalls-extractor.c                           | 6 ++++--
 4 files changed, 22 insertions(+), 2 deletions(-)
 rename {include/instrumentation/syscalls/lttng-syscalls-extractor => src}/lttng-syscalls-extractor.c (89%)

diff --git a/Makefile b/Makefile
index 81bdedac..8d25816c 100644
--- a/Makefile
+++ b/Makefile
@@ -33,6 +33,13 @@ modules:
 		KCPPFLAGS='$(LKCPPFLAGS)' \
 		modules
 
+syscalls_extractor:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD)/src \
+		CONFIG_LTTNG_SYSCALLS_EXTRACTOR=m \
+		CONFIG_LTTNG=m CONFIG_LTTNG_CLOCK_PLUGIN_TEST=m \
+		KCPPFLAGS='$(LKCPPFLAGS)' \
+		modules
+
 modules_install:
 	$(MAKE) -C $(KERNELDIR) M=$(PWD)/src \
 		CONFIG_LTTNG=m CONFIG_LTTNG_CLOCK_PLUGIN_TEST=m \
diff --git a/src/Kbuild b/src/Kbuild
index 7137874f..440b61d9 100644
--- a/src/Kbuild
+++ b/src/Kbuild
@@ -150,3 +150,5 @@ lttng-statedump-objs := lttng-statedump-impl.o
 obj-$(CONFIG_LTTNG) += probes/
 obj-$(CONFIG_LTTNG) += lib/
 obj-$(CONFIG_LTTNG) += tests/
+
+obj-$(CONFIG_LTTNG_SYSCALLS_EXTRACTOR) += lttng-syscalls-extractor.o
diff --git a/src/Kconfig b/src/Kconfig
index a2a7b8f1..c1e5781b 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -25,4 +25,13 @@ config LTTNG_EXPERIMENTAL_BITWISE_ENUM
 
 	  If unsure, say N.
 
+config LTTNG_SYSCALLS_EXTRACTOR
+	bool "LTTng syscalls extraction helper"
+	default n
+	depends on LTTNG
+	help
+	  Enable the LTTng system call extraction helper which prints the list
+	  of enabled system calls, along with their signature, to dmesg. This
+	  is not meant for mainline; it is a development helper.
+
 source "lttng/src/tests/Kconfig"
diff --git a/include/instrumentation/syscalls/lttng-syscalls-extractor/lttng-syscalls-extractor.c b/src/lttng-syscalls-extractor.c
similarity index 89%
rename from include/instrumentation/syscalls/lttng-syscalls-extractor/lttng-syscalls-extractor.c
rename to src/lttng-syscalls-extractor.c
index 8670d25f..3fba1a94 100644
--- a/include/instrumentation/syscalls/lttng-syscalls-extractor/lttng-syscalls-extractor.c
+++ b/src/lttng-syscalls-extractor.c
@@ -17,8 +17,10 @@
 #include <linux/kallsyms.h>
 #include <linux/dcache.h>
 #include <linux/trace_events.h>
+#include <linux/kprobes.h>
 #include <trace/syscall.h>
 #include <asm/syscall.h>
+#include <wrapper/kallsyms.h>
 
 #ifndef CONFIG_FTRACE_SYSCALLS
 #error "You need to set CONFIG_FTRACE_SYSCALLS=y"
@@ -56,8 +58,8 @@ int init_module(void)
 	struct syscall_metadata *meta;
 	int i;
 
-	__start_syscalls_metadata = (void *) kallsyms_lookup_name("__start_syscalls_metadata");
-	__stop_syscalls_metadata = (void *) kallsyms_lookup_name("__stop_syscalls_metadata");
+	__start_syscalls_metadata = (void *) wrapper_kallsyms_lookup_name("__start_syscalls_metadata");
+	__stop_syscalls_metadata = (void *) wrapper_kallsyms_lookup_name("__stop_syscalls_metadata");
 
 	printk("%s---START---\n", ident);
 	for (i = 0; i < NR_syscalls; i++) {
-- 
2.34.1