treewide: use get_random_u32_{above,below}() instead of manual loop

These cases were done with this Coccinelle:

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I > E);
+   I = get_random_u32_below(E + 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I >= E);
+   I = get_random_u32_below(E);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I < E);
+   I = get_random_u32_above(E - 1);

@@
expression E;
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I <= E);
+   I = get_random_u32_above(E);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (!I);
+   I = get_random_u32_above(0);

@@
identifier I;
@@
-   do {
      ... when != I
-     I = get_random_u32();
      ... when != I
-   } while (I == 0);
+   I = get_random_u32_above(0);

@@
expression E;
@@
- E + 1 + get_random_u32_below(U32_MAX - E)
+ get_random_u32_above(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 588cb09c5291fcd1f0ea6d087634df097b4d8637..4681fff6665fe612a4ada9cb920a77811281feee 100644 (file)
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -262,13 +262,7 @@ void ext4_stop_mmpd(struct ext4_sb_info *sbi)
  */
 static unsigned int mmp_new_seq(void)
 {
-       u32 new_seq;
-
-       do {
-               new_seq = get_random_u32();
-       } while (new_seq > EXT4_MMP_SEQ_MAX);
-
-       return new_seq;
+       return get_random_u32_below(EXT4_MMP_SEQ_MAX + 1);
 }
 
 /*

diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index e0381b3ec410c181fb72fa120f6b107f0250bb50..1fb56cf5e5ce62f6abd458e3ede76ad78b7d255b 100644 (file)
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -144,10 +144,7 @@ static unsigned long get_ftrace_location(void *func)
 
 static int fprobe_test_init(struct kunit *test)
 {
-       do {
-               rand1 = get_random_u32();
-       } while (rand1 <= div_factor);
-
+       rand1 = get_random_u32_above(div_factor);
        target = fprobe_selftest_target;
        target2 = fprobe_selftest_target2;
        target_ip = get_ftrace_location(target);

diff --git a/lib/test_kprobes.c b/lib/test_kprobes.c
index eeb1d728d974679f675100867caff6ef5045186b..1c95e57198023e3aa38f215272800e64db70108f 100644 (file)
--- a/lib/test_kprobes.c
+++ b/lib/test_kprobes.c
@@ -339,10 +339,7 @@ static int kprobes_test_init(struct kunit *test)
        stacktrace_target = kprobe_stacktrace_target;
        internal_target = kprobe_stacktrace_internal_target;
        stacktrace_driver = kprobe_stacktrace_driver;
-
-       do {
-               rand1 = get_random_u32();
-       } while (rand1 <= div_factor);
+       rand1 = get_random_u32_above(div_factor);
        return 0;
 }
 

diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 2685c3f15e9d30e8500f32e6b1e39ce36bf3509c..b5205311f372bdaaff140d651e4b42b27a3ed805 100644 (file)
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -15,13 +15,7 @@ static u32 __ipv6_select_ident(struct net *net,
                               const struct in6_addr *dst,
                               const struct in6_addr *src)
 {
-       u32 id;
-
-       do {
-               id = get_random_u32();
-       } while (!id);
-
-       return id;
+       return get_random_u32_above(0);
 }
 
 /* This function exists only for tap drivers that must support broken

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index ff38c5a4d174d65b54126caded46b8ffe08b12cb..d593d5b6d4b15edcbb8c378fe81f2d744e32a55e 100644 (file)
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -626,8 +626,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
        struct sockaddr_vm new_addr;
 
        if (!port)
-               port = LAST_RESERVED_PORT + 1 +
-                       get_random_u32_below(U32_MAX - LAST_RESERVED_PORT);
+               port = get_random_u32_above(LAST_RESERVED_PORT);
 
        vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);