From: Krzysztof Kozlowski <krzk@kernel.org>
To: Tudor Ambarus <tudor.ambarus@linaro.org>,
Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>,
Alim Akhtar <alim.akhtar@samsung.com>,
Kees Cook <kees@kernel.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>
Cc: linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-hardening@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH RFT 2/3] firmware: exynos-acpm: Count number of commands in acpm_xfer
Date: Thu, 19 Feb 2026 11:31:54 +0100 [thread overview]
Message-ID: <e6edf006-750a-457d-81bb-83929145e864@kernel.org> (raw)
In-Reply-To: <c9d056fb-b2ae-4631-a2b5-f55f214adecb@linaro.org>
On 19/02/2026 11:27, Tudor Ambarus wrote:
>
>
> On 2/14/26 2:39 PM, Krzysztof Kozlowski wrote:
>> Struct acpm_xfer holds two buffers with u32 commands - rxd and txd - and
>> counts their size by rxlen and txlen. "len" suffix is here ambiguous,
>> so could mean length of the buffer or length of commands, and these are
>> not the same since each command is u32. Rename these to rxcnt and
>> txcnt, and change their usage to count the number of commands in each
>> buffer.
>>
>> This will have a benafit of allowing to use __counted_by_ptr later.
>
> ^typo, benefit.
ack
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
>> ---
>> drivers/firmware/samsung/exynos-acpm-dvfs.c | 8 ++++----
>> drivers/firmware/samsung/exynos-acpm-pmic.c | 14 +++++++-------
>> drivers/firmware/samsung/exynos-acpm.c | 12 +++++++-----
>> drivers/firmware/samsung/exynos-acpm.h | 4 ++--
>> 4 files changed, 20 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/firmware/samsung/exynos-acpm-dvfs.c b/drivers/firmware/samsung/exynos-acpm-dvfs.c
>> index 1c5b2b143bcc..55ec6ad9d87e 100644
>> --- a/drivers/firmware/samsung/exynos-acpm-dvfs.c
>> +++ b/drivers/firmware/samsung/exynos-acpm-dvfs.c
>> @@ -25,11 +25,11 @@ static void acpm_dvfs_set_xfer(struct acpm_xfer *xfer, u32 *cmd, size_t cmdlen,
>> {
>> xfer->acpm_chan_id = acpm_chan_id;
>> xfer->txd = cmd;
>> - xfer->txlen = cmdlen;
>> + xfer->txcnt = cmdlen;
>>
>> if (response) {
>> xfer->rxd = cmd;
>> - xfer->rxlen = cmdlen;
>> + xfer->rxcnt = cmdlen;
>> }
>> }
>>
>> @@ -50,7 +50,7 @@ int acpm_dvfs_set_rate(const struct acpm_handle *handle,
>> u32 cmd[4];
>>
>> acpm_dvfs_init_set_rate_cmd(cmd, clk_id, rate);
>> - acpm_dvfs_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id, false);
>> + acpm_dvfs_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id, false);
>>
>> return acpm_do_xfer(handle, &xfer);
>> }
>> @@ -70,7 +70,7 @@ unsigned long acpm_dvfs_get_rate(const struct acpm_handle *handle,
>> int ret;
>>
>> acpm_dvfs_init_get_rate_cmd(cmd, clk_id);
>> - acpm_dvfs_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id, true);
>> + acpm_dvfs_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id, true);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> diff --git a/drivers/firmware/samsung/exynos-acpm-pmic.c b/drivers/firmware/samsung/exynos-acpm-pmic.c
>> index 44265db34ae6..26a9024d8ed8 100644
>> --- a/drivers/firmware/samsung/exynos-acpm-pmic.c
>> +++ b/drivers/firmware/samsung/exynos-acpm-pmic.c
>> @@ -63,8 +63,8 @@ static void acpm_pmic_set_xfer(struct acpm_xfer *xfer, u32 *cmd, size_t cmdlen,
>> {
>> xfer->txd = cmd;
>> xfer->rxd = cmd;
>> - xfer->txlen = cmdlen;
>> - xfer->rxlen = cmdlen;
>> + xfer->txcnt = cmdlen;
>> + xfer->rxcnt = cmdlen;
>> xfer->acpm_chan_id = acpm_chan_id;
>> }
>>
>> @@ -86,7 +86,7 @@ int acpm_pmic_read_reg(const struct acpm_handle *handle,
>> int ret;
>>
>> acpm_pmic_init_read_cmd(cmd, type, reg, chan);
>> - acpm_pmic_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id);
>> + acpm_pmic_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> @@ -119,7 +119,7 @@ int acpm_pmic_bulk_read(const struct acpm_handle *handle,
>> return -EINVAL;
>>
>> acpm_pmic_init_bulk_read_cmd(cmd, type, reg, chan, count);
>> - acpm_pmic_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id);
>> + acpm_pmic_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> @@ -159,7 +159,7 @@ int acpm_pmic_write_reg(const struct acpm_handle *handle,
>> int ret;
>>
>> acpm_pmic_init_write_cmd(cmd, type, reg, chan, value);
>> - acpm_pmic_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id);
>> + acpm_pmic_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> @@ -199,7 +199,7 @@ int acpm_pmic_bulk_write(const struct acpm_handle *handle,
>> return -EINVAL;
>>
>> acpm_pmic_init_bulk_write_cmd(cmd, type, reg, chan, count, buf);
>> - acpm_pmic_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id);
>> + acpm_pmic_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> @@ -229,7 +229,7 @@ int acpm_pmic_update_reg(const struct acpm_handle *handle,
>> int ret;
>>
>> acpm_pmic_init_update_cmd(cmd, type, reg, chan, value, mask);
>> - acpm_pmic_set_xfer(&xfer, cmd, sizeof(cmd), acpm_chan_id);
>> + acpm_pmic_set_xfer(&xfer, cmd, ARRAY_SIZE(cmd), acpm_chan_id);
>>
>> ret = acpm_do_xfer(handle, &xfer);
>> if (ret)
>> diff --git a/drivers/firmware/samsung/exynos-acpm.c b/drivers/firmware/samsung/exynos-acpm.c
>> index 0cb269c70460..242745e8394c 100644
>> --- a/drivers/firmware/samsung/exynos-acpm.c
>> +++ b/drivers/firmware/samsung/exynos-acpm.c
>> @@ -205,7 +205,7 @@ static void acpm_get_saved_rx(struct acpm_chan *achan,
>> rx_seqnum = FIELD_GET(ACPM_PROTOCOL_SEQNUM, rx_data->cmd[0]);
>>
>> if (rx_seqnum == tx_seqnum) {
>> - memcpy(xfer->rxd, rx_data->cmd, xfer->rxlen);
>> + memcpy(xfer->rxd, rx_data->cmd, xfer->rxcnt * sizeof(*xfer->rxd));
>> clear_bit(rx_seqnum - 1, achan->bitmap_seqnum);
>> }
>> }
>> @@ -259,7 +259,7 @@ static int acpm_get_rx(struct acpm_chan *achan, const struct acpm_xfer *xfer)
>> if (rx_data->response) {
>> if (rx_seqnum == tx_seqnum) {
>> __ioread32_copy(xfer->rxd, addr,
>> - xfer->rxlen / 4);
>> + xfer->rxcnt);
>
> now __ioread32_copy fits on a single line, without bypassing 80 chars
ack
>
>> rx_set = true;
>> clear_bit(seqnum, achan->bitmap_seqnum);
>> } else {
>> @@ -270,7 +270,7 @@ static int acpm_get_rx(struct acpm_chan *achan, const struct acpm_xfer *xfer)
>> * after the response is copied to the request.
>> */
>> __ioread32_copy(rx_data->cmd, addr,
>> - xfer->rxlen / 4);
>> + xfer->rxcnt);
>> }
>> } else {
>> clear_bit(seqnum, achan->bitmap_seqnum);
>> @@ -425,7 +425,9 @@ int acpm_do_xfer(const struct acpm_handle *handle, const struct acpm_xfer *xfer)
>>
>> achan = &acpm->chans[xfer->acpm_chan_id];
>>
>> - if (!xfer->txd || xfer->txlen > achan->mlen || xfer->rxlen > achan->mlen)
>> + if (!xfer->txd || (xfer->txcnt * sizeof(*xfer->txd) > achan->mlen))
>> + return -EINVAL;
>> + if (xfer->rxcnt * sizeof(*xfer->rxd) > achan->mlen)
>> return -EINVAL;
>
> how about:
> if (!xfer->txd ||
> (xfer->txcnt * sizeof(*xfer->txd) > achan->mlen) ||
> (xfer->rxcnt * sizeof(*xfer->rxd) > achan->mlen))
> return -EINVAL;
sure, I don't have a preference.
Best regards,
Krzysztof
next prev parent reply other threads:[~2026-02-19 10:31 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-14 12:39 [PATCH RFT 0/3] firmware: exynos-acpm: Use __counted_by() Krzysztof Kozlowski
2026-02-14 12:39 ` [PATCH RFT 1/3] firmware: exynos-acpm: Use unsigned int for acpm_pmic_linux_errmap index Krzysztof Kozlowski
2026-02-19 10:16 ` Tudor Ambarus
2026-02-14 12:39 ` [PATCH RFT 2/3] firmware: exynos-acpm: Count number of commands in acpm_xfer Krzysztof Kozlowski
2026-02-14 19:13 ` Krzysztof Kozlowski
2026-02-19 10:27 ` Tudor Ambarus
2026-02-19 10:31 ` Krzysztof Kozlowski [this message]
2026-02-14 12:39 ` [PATCH RFT 3/3] firmware: exynos-acpm: Count acpm_xfer buffers with __counted_by_ptr Krzysztof Kozlowski
2026-02-19 11:20 ` Tudor Ambarus
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