From 397cd035a40ddbc3abff2d77cb4bf6e936266944 Mon Sep 17 00:00:00 2001
From: Dirk Engling <erdgeist@erdgeist.org>
Date: Sun, 25 Apr 2021 18:23:00 +0200
Subject: Turn mmaps into malloc

---
 ot_http.c  |  2 +-
 ot_iovec.c | 57 +++++++++++++++++++++++++++++----------------------------
 ot_iovec.h |  2 +-
 ot_mutex.c |  2 +-
 4 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/ot_http.c b/ot_http.c
index 390878b..6869687 100644
--- a/ot_http.c
+++ b/ot_http.c
@@ -125,7 +125,7 @@ ssize_t http_sendiovecdata( const int64 sock, struct ot_workstruct *ws, int iove
   struct http_data *cookie = io_getcookie( sock );
   char *header;
   int i;
-  size_t header_size, size = iovec_length( &iovec_entries, &iovector );
+  size_t header_size, size = iovec_length( &iovec_entries, (const struct iovec **)&iovector );
   tai6464 t;
 
   /* No cookie? Bad socket. Leave. */
diff --git a/ot_iovec.c b/ot_iovec.c
index ec0bd12..c50003c 100644
--- a/ot_iovec.c
+++ b/ot_iovec.c
@@ -16,56 +16,57 @@
 #include "ot_iovec.h"
 
 void *iovec_increase( int *iovec_entries, struct iovec **iovector, size_t new_alloc ) {
-  void *new_ptr = realloc( *iovector, (1 + *iovec_entries ) * sizeof( struct iovec ) );
-  if( !new_ptr )
+  void *new_data;
+  int new_entries = 1 + *iovec_entries;
+  struct iovec *new_vec = realloc( *iovector, new_entries * sizeof( struct iovec ) );
+
+  if( !new_vec )
     return NULL;
-  *iovector = new_ptr;
-  new_ptr = mmap( NULL, new_alloc, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0 );
-  if( !new_ptr )
+
+  /* Only allocate after we have a place to store the pointer */
+  new_data = malloc( new_alloc );
+  if( !new_data )
     return NULL;
-  ((*iovector)[*iovec_entries]).iov_base = new_ptr;
-  ((*iovector)[*iovec_entries]).iov_len  = new_alloc;
+
+  new_vec[new_entries - 1].iov_base = new_data;
+  new_vec[new_entries - 1].iov_len  = new_alloc;
+
+  *iovector = new_vec;
   ++*iovec_entries;
-  return new_ptr;
+  return new_data;
 }
 
 void iovec_free( int *iovec_entries, struct iovec **iovector ) {
   int i;
   for( i=0; i<*iovec_entries; ++i )
-    munmap( ((*iovector)[i]).iov_base, ((*iovector)[i]).iov_len );
+    free( ((*iovector)[i]).iov_base );
+  *iovector = NULL;
   *iovec_entries = 0;
 }
 
-void  iovec_fixlast( int *iovec_entries, struct iovec **iovector, void *last_ptr ) {
-  int page_size = getpagesize();
-  size_t old_alloc, new_alloc, old_pages, new_pages;
-  char * base = (char*)((*iovector)[ *iovec_entries - 1 ]).iov_base;
-
-  if( !*iovec_entries ) return;
-
-  old_alloc = ((*iovector)[ *iovec_entries - 1 ]).iov_len;
-  new_alloc = ((char*)last_ptr) - base;
-  old_pages = 1 + old_alloc / page_size;
-  new_pages = 1 + new_alloc / page_size;
+void iovec_fixlast( int *iovec_entries, struct iovec **iovector, void *last_ptr ) {
+  if( *iovec_entries ) {
+      char * base = (char*)((*iovector)[ *iovec_entries - 1 ]).iov_base;
+      size_t new_alloc = ((char*)last_ptr) - base;
 
-  if( old_pages != new_pages )
-    munmap( base + new_pages * page_size, old_alloc - new_pages * page_size );
-  ((*iovector)[*iovec_entries - 1 ]).iov_len = new_alloc;
+      ((*iovector)[*iovec_entries - 1 ]).iov_base = realloc( base, new_alloc );
+      ((*iovector)[*iovec_entries - 1 ]).iov_len = new_alloc;
+  }
 }
 
-void  *iovec_fix_increase_or_free( int *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc ) {
-  void *new_ptr;
+void *iovec_fix_increase_or_free( int *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc ) {
+  void *new_data;
 
   iovec_fixlast( iovec_entries, iovector, last_ptr );
 
-  if( !( new_ptr = iovec_increase( iovec_entries, iovector, new_alloc ) ) )
+  if( !( new_data = iovec_increase( iovec_entries, iovector, new_alloc ) ) )
     iovec_free( iovec_entries, iovector );
 
-  return new_ptr;
+  return new_data;
 }
 
 
-size_t iovec_length( int *iovec_entries, struct iovec **iovector ) {
+size_t iovec_length( const int *iovec_entries, const struct iovec **iovector ) {
   size_t length = 0;
   int i;
   for( i=0; i<*iovec_entries; ++i )
diff --git a/ot_iovec.h b/ot_iovec.h
index 5dbe706..e48008e 100644
--- a/ot_iovec.h
+++ b/ot_iovec.h
@@ -12,7 +12,7 @@ void  *iovec_increase( int *iovec_entries, struct iovec **iovector, size_t new_a
 void   iovec_fixlast( int *iovec_entries, struct iovec **iovector, void *last_ptr );
 void   iovec_free( int *iovec_entries, struct iovec **iovector );
 
-size_t iovec_length( int *iovec_entries, struct iovec **iovector );
+size_t iovec_length( const int *iovec_entries, const struct iovec **iovector );
 
 void  *iovec_fix_increase_or_free( int *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc );
 
diff --git a/ot_mutex.c b/ot_mutex.c
index 9d87d0f..f46e3e2 100644
--- a/ot_mutex.c
+++ b/ot_mutex.c
@@ -126,7 +126,7 @@ void mutex_workqueue_canceltask( int64 sock ) {
 
     /* Free task's iovec */
     for( i=0; i<(*task)->iovec_entries; ++i )
-      munmap( iovec[i].iov_base, iovec[i].iov_len );
+      free( iovec[i].iov_base );
 
     *task = (*task)->next;
     free( ptask );
-- 
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