From: Michael Jeanson <mjeanson@efficios.com>
Date: Wed, 6 Oct 2021 16:30:25 +0000 (-0400)
Subject: Cleanup: always use sysconf to get the page size
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=81663f073dbfb4b61c06a0ceb8ca33c4fc41b1c5;p=lttng-tools.git

Cleanup: always use sysconf to get the page size

Use 'sysconf(_SC_PAGE_SIZE)' across the code base which is works on all
our supported platforms.

Change-Id: I4231d45e0b03301de1274c0a5a4903cd17b4a80a
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 868f9a4a9..4effb3ce9 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -1472,9 +1472,9 @@ int main(int argc, char **argv)
 		goto exit_set_signal_handler;
 	}
 
-	the_page_size = sysconf(_SC_PAGESIZE);
+	the_page_size = sysconf(_SC_PAGE_SIZE);
 	if (the_page_size < 0) {
-		PERROR("sysconf _SC_PAGESIZE");
+		PERROR("sysconf _SC_PAGE_SIZE");
 		the_page_size = LONG_MAX;
 		WARN("Fallback page size to %ld", the_page_size);
 	}
diff --git a/src/common/align.h b/src/common/align.h
index 024faf7fb..dff6c91d6 100644
--- a/src/common/align.h
+++ b/src/common/align.h
@@ -9,13 +9,6 @@
 #define _LTTNG_ALIGN_H
 
 #include "bug.h"
-#include <unistd.h>
-#include <limits.h>
-
-#ifndef PAGE_SIZE	/* Cygwin limits.h defines its own PAGE_SIZE. */
-#define PAGE_SIZE		sysconf(_SC_PAGE_SIZE)
-#endif
-
 
 /*
  * Align value to the next multiple of align. Returns val if it already is a
diff --git a/src/common/defaults.c b/src/common/defaults.c
index 4a5fef868..2550784cf 100644
--- a/src/common/defaults.c
+++ b/src/common/defaults.c
@@ -14,35 +14,49 @@
 
 #include "defaults.h"
 #include "macros.h"
-#include "align.h"
 #include "error.h"
 
 static int pthread_attr_init_done;
 static pthread_attr_t tattr;
 
+static size_t get_page_size(void)
+{
+	const long ret = sysconf(_SC_PAGE_SIZE);
+
+	if (ret < 0) {
+		/*
+		 * Fatal error since there is no safe way to recover from this.
+		 */
+		PERROR("Failed to get system page size using sysconf(_SC_PAGE_SIZE)");
+		abort();
+	}
+
+	return (size_t) ret;
+}
+
 size_t default_get_channel_subbuf_size(void)
 {
-	return max(_DEFAULT_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+	return max(_DEFAULT_CHANNEL_SUBBUF_SIZE, get_page_size());
 }
 
 size_t default_get_metadata_subbuf_size(void)
 {
-	return max(DEFAULT_METADATA_SUBBUF_SIZE, PAGE_SIZE);
+	return max(DEFAULT_METADATA_SUBBUF_SIZE, get_page_size());
 }
 
 size_t default_get_kernel_channel_subbuf_size(void)
 {
-	return max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+	return max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, get_page_size());
 }
 
 size_t default_get_ust_pid_channel_subbuf_size(void)
 {
-	return max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+	return max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, get_page_size());
 }
 
 size_t default_get_ust_uid_channel_subbuf_size(void)
 {
-	return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, PAGE_SIZE);
+	return max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, get_page_size());
 }
 
 pthread_attr_t *default_pthread_attr(void)
diff --git a/tests/regression/tools/trigger/hidden/hidden_trigger.c b/tests/regression/tools/trigger/hidden/hidden_trigger.c
index 5395dd224..8edd97ab2 100644
--- a/tests/regression/tools/trigger/hidden/hidden_trigger.c
+++ b/tests/regression/tools/trigger/hidden/hidden_trigger.c
@@ -70,7 +70,7 @@ int setup_session_with_size_rotation_schedule(const char *session_output_path)
 		.name = TEST_CHANNEL_NAME,
 		.enabled = 1,
 		.attr.overwrite = -1,
-		.attr.subbuf_size = sysconf(_SC_PAGESIZE) * 8,
+		.attr.subbuf_size = sysconf(_SC_PAGE_SIZE) * 8,
 		.attr.num_subbuf = 8,
 		.attr.output = LTTNG_EVENT_MMAP,
 	};
@@ -123,7 +123,7 @@ int setup_session_with_size_rotation_schedule(const char *session_output_path)
 	 * time.
 	 */
 	rotation_status = lttng_rotation_schedule_size_threshold_set_threshold(
-			rotation_schedule, sysconf(_SC_PAGESIZE) * 4096);
+			rotation_schedule, sysconf(_SC_PAGE_SIZE) * 4096);
 	if (rotation_status != LTTNG_ROTATION_STATUS_OK) {
 		fail("Failed to set size threshold of session rotation schedule");
 		ret = -1;
diff --git a/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c b/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c
index 1a2882f99..6a246867d 100644
--- a/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c
+++ b/tests/utils/testapp/gen-syscall-events/gen-syscall-events.c
@@ -37,7 +37,7 @@ void prefault_string(const char *p)
 		 * for reading.
 		 */
 		asm volatile("" : : "m"(*p));
-		p += PAGE_SIZE;
+		p += sysconf(_SC_PAGE_SIZE);
 	}
 }