sparc64: perf: Add sanity checking on addresses in user stack
Processes are getting killed (sigbus or segv) while walking userspace
callchains when using perf. In some instances I have seen ufp = 0x7ff
which does not seem like a proper stack address.
This patch adds a function to run validity checks against the address
before attempting the copy_from_user. The checks are copied from the
x86 version as a start point with the addition of a 4-byte alignment
check.
Signed-off-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index a35194b..ea6e9a2 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -49,6 +49,28 @@
__asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
} while(0)
+/*
+ * Test whether a block of memory is a valid user space address.
+ * Returns 0 if the range is valid, nonzero otherwise.
+ */
+static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
+{
+ if (__builtin_constant_p(size))
+ return addr > limit - size;
+
+ addr += size;
+ if (addr < size)
+ return true;
+
+ return addr > limit;
+}
+
+#define __range_not_ok(addr, size, limit) \
+({ \
+ __chk_user_ptr(addr); \
+ __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
+})
+
static inline int __access_ok(const void __user * addr, unsigned long size)
{
return 1;