[PATCH 3/6] x86: Mark archrandom.h functions __must_check

Richard Henderson
2019-10-28T21:06:08Z

We cannot use the pointer output without validating the
success of the random read.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/include/asm/archrandom.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h
index 5904d7d9e703..9e4ea9e53dd0 100644
--- a/arch/x86/include/asm/archrandom.h
+++ b/arch/x86/include/asm/archrandom.h
@@ -27,7 +27,7 @@

/* Unconditional execution of RDRAND and RDSEED */

-static inline bool rdrand_long(unsigned long *v)
+static inline bool __must_check rdrand_long(unsigned long *v)
{
bool ok;
unsigned int retry = RDRAND_RETRY_LOOPS;
@@ -41,7 +41,7 @@ static inline bool rdrand_long(unsigned long *v)
return false;
}

-static inline bool rdrand_int(unsigned int *v)
+static inline bool __must_check rdrand_int(unsigned int *v)
{
bool ok;
unsigned int retry = RDRAND_RETRY_LOOPS;
@@ -55,7 +55,7 @@ static inline bool rdrand_int(unsigned int *v)
return false;
}

-static inline bool rdseed_long(unsigned long *v)
+static inline bool __must_check rdseed_long(unsigned long *v)
{
bool ok;
asm volatile(RDSEED_LONG
@@ -64,7 +64,7 @@ static inline bool rdseed_long(unsigned long *v)
return ok;
}

-static inline bool rdseed_int(unsigned int *v)
+static inline bool __must_check rdseed_int(unsigned int *v)
{
bool ok;
asm volatile(RDSEED_INT
@@ -84,22 +84,22 @@ static inline bool rdseed_int(unsigned int *v)
#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND)
#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED)

-static inline bool arch_get_random_long(unsigned long *v)
+static inline bool __must_check arch_get_random_long(unsigned long *v)
{
return arch_has_random() ? rdrand_long(v) : false;
}

-static inline bool arch_get_random_int(unsigned int *v)
+static inline bool __must_check arch_get_random_int(unsigned int *v)
{
return arch_has_random() ? rdrand_int(v) : false;
}

-static inline bool arch_get_random_seed_long(unsigned long *v)
+static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
{
return arch_has_random_seed() ? rdseed_long(v) : false;
}

-static inline bool arch_get_random_seed_int(unsigned int *v)
+static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
{
return arch_has_random_seed() ? rdseed_int(v) : false;
}
--
2.17.1