From 73c19e69f3000351dc30d272a17dffa694e9b6bf Mon Sep 17 00:00:00 2001
From: Anup Patel <anup.patel@wdc.com>
Date: Fri, 3 Jan 2020 14:55:04 +0530
Subject: [PATCH] lib: zero-out memory allocated using
 sbi_scratch_alloc_offset()

We should zero-out memory allocated from extra scratch space using
sbi_scratch_alloc_offset() API hence this patch. This will not
impact performance because we mostly allocate from extra scratch
space only at cold boot time.

Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
---
 lib/sbi/sbi_scratch.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/sbi/sbi_scratch.c b/lib/sbi/sbi_scratch.c
index 0a615a2c..95ee2f2d 100644
--- a/lib/sbi/sbi_scratch.c
+++ b/lib/sbi/sbi_scratch.c
@@ -8,14 +8,21 @@
  */
 
 #include <sbi/riscv_locks.h>
+#include <sbi/sbi_hart.h>
+#include <sbi/sbi_platform.h>
 #include <sbi/sbi_scratch.h>
+#include <sbi/sbi_string.h>
 
 static spinlock_t extra_lock = SPIN_LOCK_INITIALIZER;
 static unsigned long extra_offset = SBI_SCRATCH_EXTRA_SPACE_OFFSET;
 
 unsigned long sbi_scratch_alloc_offset(unsigned long size, const char *owner)
 {
+	u32 i;
+	void *ptr;
 	unsigned long ret = 0;
+	struct sbi_scratch *scratch, *rscratch;
+	const struct sbi_platform *plat;
 
 	/*
 	 * We have a simple brain-dead allocator which never expects
@@ -43,6 +50,16 @@ unsigned long sbi_scratch_alloc_offset(unsigned long size, const char *owner)
 done:
 	spin_unlock(&extra_lock);
 
+	if (ret) {
+		scratch = sbi_scratch_thishart_ptr();
+		plat = sbi_platform_ptr(scratch);
+		for (i = 0; i < sbi_platform_hart_count(plat); i++) {
+			rscratch = sbi_hart_id_to_scratch(scratch, i);
+			ptr = sbi_scratch_offset_ptr(rscratch, ret);
+			sbi_memset(ptr, 0, size);
+		}
+	}
+
 	return ret;
 }