From: Corey Minyard <minyard@acm.org>
To: Hao Wu <wuhaotsh@google.com>
Cc: peter.maydell@linaro.org, venture@google.com,
qemu-devel@nongnu.org, hskinnemoen@google.com,
kfting@nuvoton.com, qemu-arm@nongnu.org, Avi.Fishman@nuvoton.com,
dje@google.com
Subject: Re: [PATCH 6/6] hw/i2c: Implement NPCM7XX SMBus Module FIFO Mode
Date: Tue, 26 Jan 2021 17:47:24 -0600 [thread overview]
Message-ID: <20210126234724.GC2057975@minyard.net> (raw)
In-Reply-To: <20210126193237.1534208-7-wuhaotsh@google.com>
On Tue, Jan 26, 2021 at 11:32:37AM -0800, wuhaotsh--- via wrote:
> +
> +static void npcm7xx_smbus_read_byte_fifo(NPCM7xxSMBusState *s)
> +{
> + uint8_t received_bytes = NPCM7XX_SMBRXF_STS_RX_BYTES(s->rxf_sts);
> +
> + if (received_bytes == 0) {
> + npcm7xx_smbus_recv_fifo(s);
> + return;
> + }
> +
> + s->sda = s->rx_fifo[s->rx_cur];
> + s->rx_cur = (s->rx_cur + 1u) % NPCM7XX_SMBUS_FIFO_SIZE;
> + --s->rxf_sts;
This open-coded decrement seems a little risky. Are you sure in every
case that s->rxf_sts > 0? There's no way what's running in the VM can
game this and cause a buffer overrun? One caller to this function seems
to protect against this, and another does not.
Other than this, I didn't see any issues with this patch.
-corey
next prev parent reply other threads:[~2021-01-26 23:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 19:32 [PATCH 0/6] hw/i2c: Add NPCM7XX SMBus Device wuhaotsh--- via
2021-01-26 19:32 ` [PATCH 1/6] hw/arm: Remove GPIO from unimplemented NPCM7XX wuhaotsh--- via
2021-01-26 19:32 ` [PATCH 2/6] hw/i2c: Implement NPCM7XX SMBus Module Single Mode wuhaotsh--- via
2021-01-26 23:00 ` Corey Minyard
2021-01-28 17:28 ` Peter Maydell
2021-01-26 19:32 ` [PATCH 3/6] hw/arm: Add I2C device tree for NPCM750 eval board wuhaotsh--- via
2021-01-28 17:32 ` Peter Maydell
2021-01-26 19:32 ` [PATCH 4/6] hw/arm: Add I2C device tree for Quanta GSJ wuhaotsh--- via
2021-01-26 23:05 ` Corey Minyard
2021-01-28 17:33 ` Peter Maydell
2021-01-26 19:32 ` [PATCH 5/6] hw/i2c: Add a QTest for NPCM7XX SMBus Device wuhaotsh--- via
2021-01-26 19:32 ` [PATCH 6/6] hw/i2c: Implement NPCM7XX SMBus Module FIFO Mode wuhaotsh--- via
2021-01-26 23:47 ` Corey Minyard [this message]
2021-01-27 20:37 ` wuhaotsh--- via
2021-01-27 21:42 ` Corey Minyard
2021-01-27 21:59 ` wuhaotsh--- via
2021-01-27 23:37 ` Corey Minyard
2021-01-28 5:36 ` Corey Minyard
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=20210126234724.GC2057975@minyard.net \
--to=minyard@acm.org \
--cc=Avi.Fishman@nuvoton.com \
--cc=dje@google.com \
--cc=hskinnemoen@google.com \
--cc=kfting@nuvoton.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=venture@google.com \
--cc=wuhaotsh@google.com \
/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).