From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
Remi Pommarel <repk@triplefau.lt>,
linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Jerome Brunet <jbrunet@baylibre.com>
Subject: [PATCH AUTOSEL 5.5 021/542] clk: meson: pll: Fix by 0 division in __pll_params_to_rate()
Date: Fri, 14 Feb 2020 10:40:13 -0500 [thread overview]
Message-ID: <20200214154854.6746-21-sashal@kernel.org> (raw)
In-Reply-To: <20200214154854.6746-1-sashal@kernel.org>
From: Remi Pommarel <repk@triplefau.lt>
[ Upstream commit d8488a41800d9f5c80bc0d17b9cc2c91b4841464 ]
Some meson pll registers can be initialized with 0 as N value, introducing
the following division by 0 when computing rate :
UBSAN: Undefined behaviour in drivers/clk/meson/clk-pll.c:75:9
division by zero
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-608075-g86c9af8630e1-dirty #400
Call trace:
dump_backtrace+0x0/0x1c0
show_stack+0x14/0x20
dump_stack+0xc4/0x100
ubsan_epilogue+0x14/0x68
__ubsan_handle_divrem_overflow+0x98/0xb8
__pll_params_to_rate+0xdc/0x140
meson_clk_pll_recalc_rate+0x278/0x3a0
__clk_register+0x7c8/0xbb0
devm_clk_hw_register+0x54/0xc0
meson_eeclkc_probe+0xf4/0x1a0
platform_drv_probe+0x54/0xd8
really_probe+0x16c/0x438
driver_probe_device+0xb0/0xf0
device_driver_attach+0x94/0xa0
__driver_attach+0x70/0x108
bus_for_each_dev+0xd8/0x128
driver_attach+0x30/0x40
bus_add_driver+0x1b0/0x2d8
driver_register+0xbc/0x1d0
__platform_driver_register+0x78/0x88
axg_driver_init+0x18/0x20
do_one_initcall+0xc8/0x24c
kernel_init_freeable+0x2b0/0x344
kernel_init+0x10/0x128
ret_from_fork+0x10/0x18
This checks if N is null before doing the division.
Fixes: 7a29a869434e ("clk: meson: Add support for Meson clock controller")
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
[jbrunet@baylibre.com: update the comment in above the fix]
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/meson/clk-pll.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index ddb1e56347395..3a5853ca98c6c 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -77,6 +77,15 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw,
unsigned int m, n, frac;
n = meson_parm_read(clk->map, &pll->n);
+
+ /*
+ * On some HW, N is set to zero on init. This value is invalid as
+ * it would result in a division by zero. The rate can't be
+ * calculated in this case
+ */
+ if (n == 0)
+ return 0;
+
m = meson_parm_read(clk->map, &pll->m);
frac = MESON_PARM_APPLICABLE(&pll->frac) ?
--
2.20.1
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next prev parent reply other threads:[~2020-02-14 15:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200214154854.6746-1-sashal@kernel.org>
2020-02-14 15:40 ` [PATCH AUTOSEL 5.5 019/542] media: meson: add missing allocation failure check on new_buf Sasha Levin
2020-02-14 15:40 ` [PATCH AUTOSEL 5.5 020/542] clk: meson: g12a: fix missing uart2 in regmap table Sasha Levin
2020-02-14 15:40 ` Sasha Levin [this message]
2020-02-14 15:40 ` [PATCH AUTOSEL 5.5 049/542] clk: meson: meson8b: make the CCF use the glitch-free mali mux Sasha Levin
2020-02-14 15:43 ` [PATCH AUTOSEL 5.5 243/542] crypto: amlogic - add unspecified HAS_IOMEM dependency Sasha Levin
2020-02-14 15:44 ` [PATCH AUTOSEL 5.5 300/542] ARM: dts: meson8: use the actual frequency for the GPU's 182.1MHz OPP Sasha Levin
2020-02-14 15:44 ` [PATCH AUTOSEL 5.5 301/542] ARM: dts: meson8b: use the actual frequency for the GPU's 364MHz OPP Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200214154854.6746-21-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=jbrunet@baylibre.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=martin.blumenstingl@googlemail.com \
--cc=repk@triplefau.lt \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).