From: Nicolas Pitre <nicolas.pitre@linaro.org>
Date: Sun, 24 Jul 2016 15:30:23 +0000 (-0400)
Subject: binfmt_flat: use clear_user() rather than memset() to clear .bss
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=467aa1465a7b9f0bd1a23c83bff8c38e3c3e660e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

binfmt_flat: use clear_user() rather than memset() to clear .bss

This is needed on systems with a MMU.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
---

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 8e812d7a62e0..eb747a266537 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -795,10 +795,11 @@ static int load_flat_file(struct linux_binprm *bprm,
 	flush_icache_range(start_code, end_code);
 
 	/* zero the BSS,  BRK and stack areas */
-	memset((void *)(datapos + data_len), 0, bss_len +
-			(memp + memp_size - stack_len -		/* end brk */
-			libinfo->lib_list[id].start_brk) +	/* start brk */
-			stack_len);
+	if (clear_user((void __user *)(datapos + data_len), bss_len +
+		       (memp + memp_size - stack_len -		/* end brk */
+		       libinfo->lib_list[id].start_brk) +	/* start brk */
+		       stack_len))
+		return -EFAULT;
 
 	return 0;
 err: