Use arch page size instead of hard coded 4096

Archs may use different page sizes. We must use the target arch page
size for this instead of just hard coding 4096. This must also be saved
in the data file so that it can be read by the host data.

Also fixed the bigendian routine on the recording side.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

1 files changed, 16 insertions, 8 deletions

diff --git a/trace-cmd.c b/trace-cmd.c
index 72f070b..12581bc 100644
--- a/trace-cmd.c
+++ b/trace-cmd.c
@@ -49,6 +49,8 @@
 #define ITER_CTRL       "trace_options"
 #define MAX_LATENCY     "tracing_max_latency"
 
+unsigned int page_size;
+
 static const char *output_file = "trace.dat";
 static int output_fd;
 
@@ -513,7 +515,7 @@ static int create_recorder(int cpu)
         int brass[2];
         int pid;
         int ret;
-        char buf[PAGE_SIZE];
+        char buf[page_size];
 
         pid = fork();
         if (pid < 0)
@@ -547,13 +549,13 @@ static int create_recorder(int cpu)
                 die("can not create pipe");
 
         do {
-                ret = splice(in_fd, NULL, brass[1], NULL, PAGE_SIZE, 1 /* SPLICE_F_MOVE */);
+                ret = splice(in_fd, NULL, brass[1], NULL, page_size, 1 /* SPLICE_F_MOVE */);
                 if (ret < 0) {
                         perror("in");
                         printf("errno=%d\n", errno);
                         die("splice in");
                 }
-                ret = splice(brass[0], NULL, out_fd, NULL, PAGE_SIZE, 3 /* and NON_BLOCK */);
+                ret = splice(brass[0], NULL, out_fd, NULL, page_size, 3 /* and NON_BLOCK */);
                 if (ret < 0 && errno != EAGAIN) {
                         perror("in");
                         printf("errno=%d\n", errno);
@@ -563,7 +565,7 @@ static int create_recorder(int cpu)
 
         /* splice only reads full pages */
         do {
-                ret = read(in_fd, buf, PAGE_SIZE);
+                ret = read(in_fd, buf, page_size);
                 if (ret > 0)
                         write(out_fd, buf, ret);
         } while (ret > 0);
@@ -601,13 +603,13 @@ static ssize_t write_or_die(const void *buf, size_t len)
         return ret;
 }
 
-static int bigendian(void)
+int bigendian(void)
 {
         unsigned char str[] = { 0x1, 0x2, 0x3, 0x4 };
         unsigned int *ptr;
 
         ptr = (unsigned int *)str;
-        return *ptr == 0x1234;
+        return *ptr == 0x01020304;
 }
 
 static unsigned long long copy_file_fd(int fd)
@@ -864,6 +866,7 @@ static void read_tracing_data(void)
 
         write_or_die(VERSION, strlen(VERSION) + 1);
 
+        /* save endian */
         if (bigendian())
                 buf[0] = 1;
         else
@@ -871,9 +874,14 @@ static void read_tracing_data(void)
 
         write_or_die(buf, 1);
 
+        /* save size of long */
         buf[0] = sizeof(long);
         write_or_die(buf, 1);
 
+        /* save page_size */
+        page_size = getpagesize();
+        write_or_die(&page_size, 4);
+
         read_header_files();
         read_ftrace_files();
         read_event_files();
@@ -947,7 +955,7 @@ static void read_thread_data(void)
 
         /* hold any extra data for data */
         offset += cpu_count * (16);
-        offset = (offset + (PAGE_SIZE - 1)) & ~(PAGE_MASK);
+        offset = (offset + (page_size - 1)) & ~(PAGE_MASK);
 
         for (i = 0; i < cpu_count; i++) {
                 file = malloc_or_die(strlen(output_file) + 20);
@@ -959,7 +967,7 @@ static void read_thread_data(void)
                 offsets[i] = offset;
                 sizes[i] = st.st_size;
                 offset += st.st_size;
-                offset = (offset + (PAGE_SIZE - 1)) & ~(PAGE_MASK);
+                offset = (offset + (page_size - 1)) & ~(PAGE_MASK);
 
                 write_or_die(&offsets[i], 8);
                 write_or_die(&sizes[i], 8);