sparc: Use __builtin_object_size() to validate the buffer size for copy_from_user()

This mirrors x86 commit 9f0cf4adb6aa0bfccf675c938124e68f7f06349d
(x86: Use __builtin_object_size() to validate the buffer size for copy_from_user())

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug
index 90d5fe223a7..9d3c889718a 100644
--- a/arch/sparc/Kconfig.debug
+++ b/arch/sparc/Kconfig.debug
@@ -33,4 +33,18 @@ config FRAME_POINTER
 	depends on MCOUNT
 	default y
 
+config DEBUG_STRICT_USER_COPY_CHECKS
+	bool "Strict copy size checks"
+	depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
+	---help---
+	  Enabling this option turns a certain set of sanity checks for user
+	  copy operations into compile time failures.
+
+	  The copy_from_user() etc checks are there to help test if there
+	  are sufficient security checks on the length argument of
+	  the copy operation, by having gcc prove that the argument is
+	  within bounds.
+
+	  If unsure, or if you run an older (pre 4.4) gcc, say N.
+
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