From c4b2f313204c73a403ff9677a4d38c68581c5dd9 Mon Sep 17 00:00:00 2001
From: Dr-Noob <peibolms@gmail.com>
Date: Wed, 9 Feb 2022 22:16:13 +0100
Subject: [PATCH] [v1.01] Read file in udev by dynamically reallocating a
 buffer, instead of allocating a fixed size. Should fix issue #137

---
 src/common/global.c | 12 ++++++++++++
 src/common/global.h |  1 +
 src/common/udev.c   | 12 +++++++++---
 src/common/udev.h   |  1 -
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/common/global.c b/src/common/global.c
index 47d4752..0545b2d 100644
--- a/src/common/global.c
+++ b/src/common/global.c
@@ -111,3 +111,15 @@ void* ecalloc(size_t nmemb, size_t size) {
 
   return ptr;
 }
+
+void* erealloc(void *ptr, size_t size) {
+  void* newptr = realloc(ptr, size);
+
+  if(newptr == NULL) {
+    printErr("realloc failed: %s", strerror(errno));
+    exit(1);
+  }
+
+  return newptr;
+}
+
diff --git a/src/common/global.h b/src/common/global.h
index 3fa8688..5e5a0b3 100644
--- a/src/common/global.h
+++ b/src/common/global.h
@@ -15,5 +15,6 @@ int max(int a, int b);
 char *strremove(char *str, const char *sub);
 void* emalloc(size_t size);
 void* ecalloc(size_t nmemb, size_t size);
+void* erealloc(void *ptr, size_t size);
 
 #endif
diff --git a/src/common/udev.c b/src/common/udev.c
index 75c60b2..395c637 100644
--- a/src/common/udev.c
+++ b/src/common/udev.c
@@ -55,11 +55,17 @@ char* read_file(char* path, int* len) {
   int bytes_read = 0;
   int offset = 0;
   int block = 128;
-  char* buf = emalloc(sizeof(char)*DEFAULT_FILE_SIZE);
-  memset(buf, 0, sizeof(char)*DEFAULT_FILE_SIZE);
+  int buf_size = block * 4;
+  char* buf = emalloc(sizeof(char) * buf_size);
+  memset(buf, 0, sizeof(char) * buf_size);
 
-  while (  (bytes_read = read(fd, buf+offset, block)) > 0 ) {
+  while ((bytes_read = read(fd, buf+offset, block)) > 0) {
     offset += bytes_read;
+    if(offset + block > buf_size) {
+      buf = erealloc(buf, sizeof(char) * buf_size * 2);
+      memset(buf + buf_size, 0, sizeof(char) * buf_size);
+      buf_size = buf_size * 2;
+    }
   }
 
   if (close(fd) == -1) {
diff --git a/src/common/udev.h b/src/common/udev.h
index b181b5f..ece967c 100644
--- a/src/common/udev.h
+++ b/src/common/udev.h
@@ -27,7 +27,6 @@
 
 #define _PATH_FREQUENCY_MAX_LEN 100
 #define _PATH_CACHE_MAX_LEN     200
-#define DEFAULT_FILE_SIZE       4096
 
 char* read_file(char* path, int* len);
 long get_max_freq_from_file(uint32_t core);