From 7414f8daec56ec91d756ca07d354db8ed34b94b5 Mon Sep 17 00:00:00 2001
From: Andrea Mazzoleni <amadvance@gmail.com>
Date: Sun, 27 Oct 2013 17:31:10 +0100
Subject: [PATCH] Adds a basic memory test on the used memory buffers.

---
 HISTORY    |  2 ++
 check.c    |  2 ++
 scrub.c    |  2 ++
 selftest.c |  2 ++
 speed.c    |  1 +
 sync.c     |  2 ++
 util.c     | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 util.h     |  6 ++++++
 8 files changed, 67 insertions(+)

diff --git a/HISTORY b/HISTORY
index 6fe1b56b..afee144e 100644
--- a/HISTORY
+++ b/HISTORY
@@ -23,6 +23,8 @@ SnapRAID HISTORY
  * Changed the output format of some commands to make it similar
    at the new "list" one.
  * Reduced memory usage removing some unnecessary allocations.
+ * Added a memory test on the memory buffers used in sync/scrub/check/fix
+   before using them.
 
 4.4 2013/10
 ===========
diff --git a/check.c b/check.c
index c404ad01..a6696370 100644
--- a/check.c
+++ b/check.c
@@ -482,6 +482,8 @@ static int state_check_process(struct snapraid_state* state, int check, int fix,
 	buffermax = diskmax + state->level * 2 + 1;
 
 	buffer = malloc_nofail_vector_align(buffermax, state->block_size, &buffer_alloc);
+	if (!state->opt.skip_self)
+		mtest_vector(buffer, buffermax, state->block_size);
 
 	/* fill up the zero buffer */
 	memset(buffer[buffermax-1], 0, state->block_size);
diff --git a/scrub.c b/scrub.c
index 8006dcff..3e0b81a5 100644
--- a/scrub.c
+++ b/scrub.c
@@ -68,6 +68,8 @@ static int state_scrub_process(struct snapraid_state* state, struct snapraid_par
 	buffermax = diskmax + state->level * 2;
 
 	buffer = malloc_nofail_vector_align(buffermax, state->block_size, &buffer_alloc);
+	if (!state->opt.skip_self)
+		mtest_vector(buffer, buffermax, state->block_size);
 
 	error = 0;
 	silent_error = 0;
diff --git a/selftest.c b/selftest.c
index 0a54db04..19b19acd 100644
--- a/selftest.c
+++ b/selftest.c
@@ -66,6 +66,7 @@ static void recovtest(int diskmax, unsigned block_size)
 	buffermax = diskmax + LEV_MAX * 2 + 2;
 
 	buffer = malloc_nofail_vector_align(buffermax, block_size, &buffer_alloc);
+	mtest_vector(buffer, buffermax, block_size);
 
 	data = buffer;
 	parity = buffer + diskmax;
@@ -336,6 +337,7 @@ static void gentest(unsigned diskmax, unsigned block_size)
 	buffermax = diskmax + LEV_MAX * 2;
 
 	buffer = malloc_nofail_vector_align(buffermax, block_size, &buffer_alloc);
+	mtest_vector(buffer, buffermax, block_size);
 
 	/* fill with random */
 	for(i=0;i<diskmax;++i) {
diff --git a/speed.c b/speed.c
index 8dc0a169..1a32c18e 100644
--- a/speed.c
+++ b/speed.c
@@ -70,6 +70,7 @@ void speed(void)
 	unsigned char* zero;
 
 	buffer = malloc_nofail_vector_align(diskmax + LEV_MAX + 1, block_size, &buffer_alloc);
+	mtest_vector(buffer, diskmax + LEV_MAX + 1, block_size);
 
 	/* initialize with fixed data */
 	for(i=0;i<diskmax+LEV_MAX;++i) {
diff --git a/sync.c b/sync.c
index 670eea41..e4c538ff 100644
--- a/sync.c
+++ b/sync.c
@@ -75,6 +75,8 @@ static int state_sync_process(struct snapraid_state* state, struct snapraid_pari
 	buffermax = diskmax + state->level;
 
 	buffer = malloc_nofail_vector_align(buffermax, state->block_size, &buffer_alloc);
+	if (!state->opt.skip_self)
+		mtest_vector(buffer, buffermax, state->block_size);
 
 	error = 0;
 	silent_error = 0;
diff --git a/util.c b/util.c
index 0177b4d3..27c13667 100644
--- a/util.c
+++ b/util.c
@@ -1388,6 +1388,56 @@ unsigned char** malloc_nofail_vector_align(size_t count, size_t size, void** fre
 	return buffer;
 }
 
+void mtest_vector(unsigned char** buf, size_t count, size_t size)
+{
+	size_t i;
+	size_t j;
+	unsigned k;
+	unsigned char d;
+	unsigned char p;
+
+	/* fill with 0 */
+	d = 0;
+	for(i=0;i<count;++i) {
+		for(j=0;j<size;++j) {
+			buf[i][j] = d;
+		}
+	}
+
+	/* test with all the byte patterns */
+	for(k=1;k<256;++k) {
+		p = d;
+		d = k;
+
+		/* forward fill */
+		for(i=0;i<count;++i) {
+			for(j=0;j<size;++j) {
+				if (buf[i][j] != p)
+					goto fail;
+				buf[i][j] = d;
+			}
+		}
+
+		p = d;
+		d = ~p;
+		/* backward fill with complement */
+		for(i=0;i<count;++i) {
+			for(j=size;j>0;--j) {
+				if (buf[i][j-1] != p)
+					goto fail;
+				buf[i][j-1] = d;
+			}
+		}
+	}
+
+	return;
+
+fail:
+	fprintf(stderr, "DANGER! Your RAM memory is broken! DO NOT PROCEED UNTIL FIXED!\n");
+	fprintf(stderr, "Try running some memory test like http://www.memtest86.com/\n");
+	exit(EXIT_FAILURE);
+}
+
 char* strdup_nofail(const char* str)
 {
 	size_t size;
diff --git a/util.h b/util.h
index 1782c399..d39885c0 100644
--- a/util.h
+++ b/util.h
@@ -464,6 +464,12 @@ void* malloc_nofail_align(size_t size, void** freeptr);
  */
 unsigned char** malloc_nofail_vector_align(size_t count, size_t size, void** freeptr);
 
+/**
+ * Test the memory vector for RAM problems.
+ * If a problem is found, it crashes.
+ */
+void mtest_vector(unsigned char** buf, size_t count, size_t size);
+
 /**
  * Safe strdup.
  * If no memory is available, it aborts.