From: Walter Harms <wharms@bfs.de>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
Alim Akhtar <alim.akhtar@samsung.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Thomas Abraham <thomas.abraham@linaro.org>,
"Kukjin Kim" <kgene.kim@samsung.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-samsung-soc@vger.kernel.org"
<linux-samsung-soc@vger.kernel.org>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>
Subject: AW: [PATCH 2/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
Date: Fri, 9 Jun 2023 08:57:14 +0000 [thread overview]
Message-ID: <f31523d7270d4a1f82d96b7891ed13e6@bfs.de> (raw)
In-Reply-To: <93bf8f574310256fcea50e5c5a62b5c37e20bb14.1686285892.git.christophe.jaillet@wanadoo.fr>
while we are here ....
perhaps INT_MAX from kernel.h ?
int deviation = (1 << 30) - 1;
the part before looks a bit strange
if (ourport->info->has_divslot) {
unsigned long div = rate / req_baud;
/* The UDIVSLOT register on the newer UARTs allows us to
* get a divisor adjustment of 1/16th on the baud clock.
*
* We don't keep the UDIVSLOT value (the 16ths we
* calculated by not multiplying the baud by 16) as it
* is easy enough to recalculate.
*/
quot = div / 16;
baud = rate / div;
because
baud=rate/rate/req_baud = req_baud
can this be simplyfied ? (or is the numeric required ?)
Homebrew abs() kernel.h has a abs() can we use it here ?
if (calc_deviation < 0)
calc_deviation = -calc_deviation;
to the patch:
+ /*
+ * If we find a better clk, release the previous one, if
+ * any.
+ */
+ if (!IS_ERR(*best_clk))
+ clk_put(*best_clk);
the intentions are good. *best_clk is user supplied (and should be NULL)
filled & released in the next round but IMHO must be valid (is clk).
so no need to check. (ntl clk_put seems to handle NULL and ERR )
if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
return;
JM2C
wh
________________________________________
Von: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Gesendet: Freitag, 9. Juni 2023 06:45:39
An: Krzysztof Kozlowski; Alim Akhtar; Greg Kroah-Hartman; Jiri Slaby; Thomas Abraham; Kukjin Kim
Cc: linux-kernel@vger.kernel.org; kernel-janitors@vger.kernel.org; Christophe JAILLET; linux-arm-kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org; linux-serial@vger.kernel.org
Betreff: [PATCH 2/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
When the best clk is searched, we iterate over all possible clk.
If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This patch is speculative. Review with care.
I think that some clk_put() are also missing somewhere else in the driver
but won't be able to investigate further.
---
drivers/tty/serial/samsung_tty.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index dd751e7010e3..c07877dd25fa 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1488,10 +1488,18 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
calc_deviation = -calc_deviation;
if (calc_deviation < deviation) {
+ /*
+ * If we find a better clk, release the previous one, if
+ * any.
+ */
+ if (!IS_ERR(*best_clk))
+ clk_put(*best_clk);
*best_clk = clk;
best_quot = quot;
*clk_num = cnt;
deviation = calc_deviation;
+ } else {
+ clk_put(clk);
}
}
--
2.34.1
next prev parent reply other threads:[~2023-06-09 12:36 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-09 4:45 [PATCH 1/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error Christophe JAILLET
2023-06-09 4:45 ` [PATCH 2/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk Christophe JAILLET
2023-06-09 8:57 ` Walter Harms [this message]
2023-06-09 11:56 ` AW: " Krzysztof Kozlowski
2023-06-09 16:17 ` Christophe JAILLET
2023-06-09 11:53 ` Krzysztof Kozlowski
2023-06-10 10:39 ` Andi Shyti
2023-06-10 10:45 ` Krzysztof Kozlowski
2023-06-10 10:57 ` Andi Shyti
2023-06-09 11:51 ` [PATCH 1/2] tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error Krzysztof Kozlowski
2023-06-10 10:26 ` Andi Shyti
2023-06-10 14:07 ` Christophe JAILLET
2023-06-10 14:54 ` Andi Shyti
2023-06-10 16:23 ` Krzysztof Kozlowski
2023-06-10 17:10 ` Andi Shyti
2023-06-10 17:32 ` Krzysztof Kozlowski
2023-06-10 17:40 ` Christophe JAILLET
2023-06-12 4:53 ` Dan Carpenter
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