From 7c5897933f4f64594602b2e38264af705c061754 Mon Sep 17 00:00:00 2001
From: "Suren A. Chilingaryan" <csa@suren.me>
Date: Wed, 5 Aug 2015 18:11:59 +0200
Subject: Use global locks to protect kmem allocation to prevent race while
 allocating simmultaneously locking kmem pages and any other type of kmem

---
 pcilib/bar.c     | 9 +++++----
 pcilib/kmem.c    | 6 +++---
 pcilib/lock.c    | 5 ++++-
 pcilib/locking.c | 6 +-----
 pcilib/locking.h | 2 +-
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/pcilib/bar.c b/pcilib/bar.c
index 17828a8..418f864 100644
--- a/pcilib/bar.c
+++ b/pcilib/bar.c
@@ -80,7 +80,7 @@ void *pcilib_map_bar(pcilib_t *ctx, pcilib_bar_t bar) {
 
     if (ctx->bar_space[bar]) return ctx->bar_space[bar];
 
-    err = pcilib_lock(ctx->locks.mmap);
+    err = pcilib_lock_global(ctx);
     if (err) {
 	pcilib_error("Error (%i) acquiring mmap lock", err);
 	return NULL;
@@ -88,14 +88,14 @@ void *pcilib_map_bar(pcilib_t *ctx, pcilib_bar_t bar) {
 
     ret = ioctl( ctx->handle, PCIDRIVER_IOC_MMAP_MODE, PCIDRIVER_MMAP_PCI );
     if (ret) {
-	pcilib_unlock(ctx->locks.mmap);
+	pcilib_unlock_global(ctx);
 	pcilib_error("PCIDRIVER_IOC_MMAP_MODE ioctl have failed", bar);
 	return NULL;
     }
 
     ret = ioctl( ctx->handle, PCIDRIVER_IOC_MMAP_AREA, PCIDRIVER_BAR0 + bar );
     if (ret) {
-	pcilib_unlock(ctx->locks.mmap);
+	pcilib_unlock_global(ctx);
 	pcilib_error("PCIDRIVER_IOC_MMAP_AREA ioctl have failed for bank %i", bar);
 	return NULL;
     }
@@ -106,7 +106,8 @@ void *pcilib_map_bar(pcilib_t *ctx, pcilib_bar_t bar) {
 #else
     res = mmap( 0, board_info->bar_length[bar], PROT_WRITE | PROT_READ, MAP_SHARED, ctx->handle, 0 );
 #endif
-    pcilib_unlock(ctx->locks.mmap);
+
+    pcilib_unlock_global(ctx);
 
     if ((!res)||(res == MAP_FAILED)) {
 	pcilib_error("Failed to mmap data bank %i", bar);
diff --git a/pcilib/kmem.c b/pcilib/kmem.c
index 469c63a..b1d2c5c 100644
--- a/pcilib/kmem.c
+++ b/pcilib/kmem.c
@@ -80,7 +80,7 @@ pcilib_kmem_handle_t *pcilib_alloc_kernel_memory(pcilib_t *ctx, pcilib_kmem_type
     
     memset(kbuf, 0, sizeof(pcilib_kmem_list_t) + nmemb * sizeof(pcilib_kmem_addr_t));
 
-    err = pcilib_lock(ctx->locks.mmap);
+    err = pcilib_lock_global(ctx);
     if (err) {
 	pcilib_error("Error (%i) acquiring mmap lock", err);
 	return NULL;
@@ -88,7 +88,7 @@ pcilib_kmem_handle_t *pcilib_alloc_kernel_memory(pcilib_t *ctx, pcilib_kmem_type
 
     ret = ioctl( ctx->handle, PCIDRIVER_IOC_MMAP_MODE, PCIDRIVER_MMAP_KMEM );
     if (ret) {
-	pcilib_unlock(ctx->locks.mmap);
+	pcilib_unlock_global(ctx);
 	pcilib_error("PCIDRIVER_IOC_MMAP_MODE ioctl have failed");
 	return NULL;
     }
@@ -176,7 +176,7 @@ pcilib_kmem_handle_t *pcilib_alloc_kernel_memory(pcilib_t *ctx, pcilib_kmem_type
 	kbuf->buf.blocks[i].mmap_offset = kh.pa & ctx->page_mask;
     }
 
-    pcilib_unlock(ctx->locks.mmap);
+    pcilib_unlock_global(ctx);
 
 
 	//This is possible in the case of error (nothing is allocated yet) or if buffers are not reused
diff --git a/pcilib/lock.c b/pcilib/lock.c
index f1cbc56..13e363a 100644
--- a/pcilib/lock.c
+++ b/pcilib/lock.c
@@ -140,7 +140,10 @@ const char *pcilib_lock_get_name(pcilib_lock_t *lock) {
 int pcilib_lock_custom(pcilib_lock_t *lock, pcilib_lock_flags_t flags, pcilib_timeout_t timeout) {
     int err;
 
-    if (!lock) return 0;
+    if (!lock) {
+	pcilib_error("The null lock pointer is passed to lock function");
+	return PCILIB_ERROR_INVALID_ARGUMENT;
+    }
 
     struct timespec tm;
 
diff --git a/pcilib/locking.c b/pcilib/locking.c
index ffd05ce..7a32605 100644
--- a/pcilib/locking.c
+++ b/pcilib/locking.c
@@ -46,11 +46,10 @@ int pcilib_init_locking(pcilib_t* ctx) {
     }
 
     ctx->locks.locking = pcilib_get_lock(ctx, PCILIB_LOCK_FLAG_UNLOCKED, "locking");
-    ctx->locks.mmap = pcilib_get_lock(ctx,  PCILIB_LOCK_FLAG_UNLOCKED, "mmap");
 
     pcilib_unlock_global(ctx);
 
-    if ((!ctx->locks.locking)||(!ctx->locks.mmap)) {
+    if ((!ctx->locks.locking)) {
 	pcilib_error("Locking subsystem has failed to initialized mandatory global locks");
 	return PCILIB_ERROR_FAILED;
     }
@@ -62,9 +61,6 @@ int pcilib_init_locking(pcilib_t* ctx) {
  * this functions destroy all locks and then free the kernel memory allocated for them
  */
 void pcilib_free_locking(pcilib_t *ctx) {
-    if (ctx->locks.mmap)
-	pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, ctx->locks.mmap);
-
     if (ctx->locks.locking)
 	pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, ctx->locks.locking);
 
diff --git a/pcilib/locking.h b/pcilib/locking.h
index ae2f368..ccacd63 100644
--- a/pcilib/locking.h
+++ b/pcilib/locking.h
@@ -20,7 +20,7 @@ typedef struct pcilib_locking_s pcilib_locking_t;
 struct pcilib_locking_s {
     pcilib_kmem_handle_t *kmem;							/**< kmem used to store mutexes */
     pcilib_lock_t *locking;							/**< lock used while intializing other locks */
-    pcilib_lock_t *mmap;							/**< lock used to protect mmap operation */
+//    pcilib_lock_t *mmap;							/**< lock used to protect mmap operation */
 };
 
 #ifdef __cplusplus
-- 
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