1 files changed, 68 insertions, 48 deletions

diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 7cd1193918c7..cb54cd002f49 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -50,14 +50,51 @@ static int long_size;
 
 static unsigned long    page_size;
 
+static ssize_t calc_data_size;
+static bool repipe;
+
+/* If it fails, the next read will report it */
+static void skip(int size)
+{
+        lseek(input_fd, size, SEEK_CUR);
+}
+
+static int do_read(int fd, void *buf, int size)
+{
+        int rsize = size;
+
+        while (size) {
+                int ret = read(fd, buf, size);
+
+                if (ret <= 0)
+                        return -1;
+
+                if (repipe) {
+                        int retw = write(STDOUT_FILENO, buf, ret);
+
+                        if (retw <= 0 || retw != ret)
+                                die("repiping input file");
+                }
+
+                size -= ret;
+                buf += ret;
+        }
+
+        return rsize;
+}
+
 static int read_or_die(void *data, int size)
 {
         int r;
 
-        r = read(input_fd, data, size);
-        if (r != size)
+        r = do_read(input_fd, data, size);
+        if (r <= 0)
                 die("reading input file (size expected=%d received=%d)",
                     size, r);
+
+        if (calc_data_size)
+                calc_data_size += r;
+
         return r;
 }
 
@@ -82,57 +119,36 @@ static char *read_string(void)
         char buf[BUFSIZ];
         char *str = NULL;
         int size = 0;
-        int i;
         off_t r;
+        char c;
 
         for (;;) {
-                r = read(input_fd, buf, BUFSIZ);
+                r = read(input_fd, &c, 1);
                 if (r < 0)
                         die("reading input file");
 
                 if (!r)
                         die("no data");
 
-                for (i = 0; i < r; i++) {
-                        if (!buf[i])
-                                break;
-                }
-                if (i < r)
-                        break;
+                if (repipe) {
+                        int retw = write(STDOUT_FILENO, &c, 1);
 
-                if (str) {
-                        size += BUFSIZ;
-                        str = realloc(str, size);
-                        if (!str)
-                                die("malloc of size %d", size);
-                        memcpy(str + (size - BUFSIZ), buf, BUFSIZ);
-                } else {
-                        size = BUFSIZ;
-                        str = malloc_or_die(size);
-                        memcpy(str, buf, size);
+                        if (retw <= 0 || retw != r)
+                                die("repiping input file string");
                 }
-        }
 
-        /* trailing \0: */
-        i++;
-
-        /* move the file descriptor to the end of the string */
-        r = lseek(input_fd, -(r - i), SEEK_CUR);
-        if (r == (off_t)-1)
-                die("lseek");
-
-        if (str) {
-                size += i;
-                str = realloc(str, size);
-                if (!str)
-                        die("malloc of size %d", size);
-                memcpy(str + (size - i), buf, i);
-        } else {
-                size = i;
-                str = malloc_or_die(i);
-                memcpy(str, buf, i);
+                buf[size++] = c;
+
+                if (!c)
+                        break;
         }
 
+        if (calc_data_size)
+                calc_data_size += size;
+
+        str = malloc_or_die(size);
+        memcpy(str, buf, size);
+
         return str;
 }
 
@@ -174,7 +190,6 @@ static void read_ftrace_printk(void)
 static void read_header_files(void)
 {
         unsigned long long size;
-        char *header_page;
         char *header_event;
         char buf[BUFSIZ];
 
@@ -184,10 +199,7 @@ static void read_header_files(void)
                 die("did not read header page");
 
         size = read8();
-        header_page = malloc_or_die(size);
-        read_or_die(header_page, size);
-        parse_header_page(header_page, size);
-        free(header_page);
+        skip(size);
 
         /*
          * The size field in the page is of type long,
@@ -459,7 +471,7 @@ struct record *trace_read_data(int cpu)
         return data;
 }
 
-void trace_report(int fd)
+ssize_t trace_report(int fd, bool __repipe)
 {
         char buf[BUFSIZ];
         char test[] = { 23, 8, 68 };
@@ -467,6 +479,10 @@ void trace_report(int fd)
         int show_version = 0;
         int show_funcs = 0;
         int show_printk = 0;
+        ssize_t size;
+
+        calc_data_size = 1;
+        repipe = __repipe;
 
         input_fd = fd;
 
@@ -499,14 +515,18 @@ void trace_report(int fd)
         read_proc_kallsyms();
         read_ftrace_printk();
 
+        size = calc_data_size - 1;
+        calc_data_size = 0;
+        repipe = false;
+
         if (show_funcs) {
                 print_funcs();
-                return;
+                return size;
         }
         if (show_printk) {
                 print_printk();
-                return;
+                return size;
         }
 
-        return;
+        return size;
 }