From 077bb7a1baec75bd2d7d08e2cbdeb5b72344a4ad Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Sun, 13 Feb 2022 21:46:29 +0100
Subject: [PATCH] hwrng: core - start and stop in-kernel rngd in separate
function
Extract the start/stop logic for the in-kernel rngd thread to
a separate function.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
drivers/char/hw_random/core.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 6f09f4e5af20f..29febf55b0d46 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -51,7 +51,7 @@ MODULE_PARM_DESC(default_quality,
static void drop_current_rng(void);
static int hwrng_init(struct hwrng *rng);
-static void start_khwrngd(void);
+static void hwrng_manage_rngd(void);
static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size,
int wait);
@@ -164,10 +164,7 @@ static int hwrng_init(struct hwrng *rng)
if (current_quality > 1024)
current_quality = 1024;
- if (current_quality == 0 && hwrng_fill)
- kthread_stop(hwrng_fill);
- if (current_quality > 0 && !hwrng_fill)
- start_khwrngd();
+ hwrng_manage_rngd();
return 0;
}
@@ -466,12 +463,19 @@ static int hwrng_fillfn(void *unused)
return 0;
}
-static void start_khwrngd(void)
+static void hwrng_manage_rngd(void)
{
- hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng");
- if (IS_ERR(hwrng_fill)) {
- pr_err("hwrng_fill thread creation failed\n");
- hwrng_fill = NULL;
+ if (WARN_ON(!mutex_is_locked(&rng_mutex)))
+ return;
+
+ if (current_quality == 0 && hwrng_fill)
+ kthread_stop(hwrng_fill);
+ if (current_quality > 0 && !hwrng_fill) {
+ hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng");
+ if (IS_ERR(hwrng_fill)) {
+ pr_err("hwrng_fill thread creation failed\n");
+ hwrng_fill = NULL;
+ }
}
}
--
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