From: Bruce Richardson <bruce.richardson@intel.com>
To: "Morten Brørup" <mb@smartsharesystems.com>
Cc: "lihuisong (C)" <lihuisong@huawei.com>, <dev@dpdk.org>,
<andrew.rybchenko@oktetlabs.ru>, <huangdaode@huawei.com>,
<liudongdong3@huawei.com>, <fengchengwen@huawei.com>
Subject: Re: [PATCH V6 6/8] telemetry: support adding integer value as hexadecimal
Date: Thu, 15 Dec 2022 12:15:51 +0000 [thread overview]
Message-ID: <Y5sP97VSDtUP6lfX@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35D875AD@smartserver.smartshare.dk>
On Thu, Dec 15, 2022 at 01:00:40PM +0100, Morten Brørup wrote:
> > From: lihuisong (C) [mailto:lihuisong@huawei.com]
> > Sent: Thursday, 15 December 2022 12.28
> >
> > 在 2022/12/15 18:46, Bruce Richardson 写道:
> > > On Thu, Dec 15, 2022 at 06:31:44PM +0800, Huisong Li wrote:
> > >> Sometimes displaying a unsigned integer value as hexadecimal encoded
> > style
> > >> is more expected for human consumption, such as, offload capability
> > and
> > >> device flag. This patch introduces two APIs to add unsigned integer
> > value
> > >> as hexadecimal encoded string to array or dictionary. And user can
> > choose
> > >> whether the stored value is padding to the specified width.
> > >>
> > >> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> > >> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> > >> Acked-by: Chengwen Feng <fengchengwen@huawei.com>
> > >> ---
> > >> lib/telemetry/rte_telemetry.h | 47 ++++++++++++++++++++++
> > >> lib/telemetry/telemetry_data.c | 72
> > ++++++++++++++++++++++++++++++++++
> > >> lib/telemetry/version.map | 9 +++++
> > >> 3 files changed, 128 insertions(+)
> > >>
> > > <snip>
> > >> +/* To suppress compiler warning about format string. */
> > >> +#if defined(RTE_TOOLCHAIN_GCC)
> > >> +#pragma GCC diagnostic push
> > >> +#pragma GCC diagnostic ignored "-Wformat-nonliteral"
> > >> +#elif defined(RTE_TOOLCHAIN_CLANG)
> > >> +#pragma clang diagnostic push
> > >> +#pragma clang diagnostic ignored "-Wformat-nonliteral"
> > >> +#endif
> > >> +
> > >> +static int
> > >> +rte_tel_uint_to_hex_encoded_str(char *buf, uint16_t len, uint64_t
> > val,
>
> The "len" parameter should be size_t or unsigned int, not uint16_t.
>
> And as a personal preference, I would name it "buf_len" instead of "len".
>
> > >> + uint8_t display_bitwidth)
> > >> +{
> > >> +#define RTE_TEL_UINT_HEX_FORMAT_LEN 16
> > >> +
> > >> + uint8_t spec_hex_width = (display_bitwidth + 3) / 4;
> > >> + char format[RTE_TEL_UINT_HEX_FORMAT_LEN];
> > >> +
> > >> + /* Buffer needs to have room to contain the prefix '0x' and '\0'.
> > */
> > >> + if (len < spec_hex_width + 3)
> > >> + return -EINVAL;
> > >> +
> > > This check is not sufficient, as display_bitwidth could be 0 for
> > example,
> > > and the actual printed number have up to 16 characters.
> > Yes, you are right. What do you think of the following check?
> >
> > max_hex_width = display_bitwidth == 0 ? (sizeof(uint64_t) * 2) :
> > spec_hex_width;
> > if (len < max_hex_width + 3)
> > return -EINVAL;
>
> LGTM.
That would work, but actually I think we should drop this check completely
- see comment below.
>
> > >
> > >> + if (display_bitwidth != 0) {
> > >> + sprintf(format, "0x%%0%u" PRIx64, spec_hex_width);
> > >> + sprintf(buf, format, val);
>
> snprintf(format, sizeof(format), "0x%%0%u" PRIx64, spec_hex_width);
> snprintf(buf, len, format, val);
>
> > >> + } else {
> > >> + sprintf(buf, "0x%" PRIx64, val);
>
> snprintf(buf, len, "0x%" PRIx64, val);
>
> > >> + }
> > >> +
> > > snprintf should always be used when printing to the buffer so as to
> > avoid
> > > overflow. The return value after snprintf should always be checked
> > too.
> > If check for buffer is sufficient, can the return value of snprintf not
> > be checked?
> > There are also many places in telemetry lib that are not checked for
> > this return value.
> > Do you have any principles for this?
>
> You already check the buffer size before printf() into it, so I think it suffices. However, to keep automated code checkers happy, you could easily use snprintf() instead of printf(). (Sorry about not doing it in my example.)
>
> I somewhat disagree with Bruce's suggestion to check the return value from snprintf() after checking that the buffer is large enough. It would be effectively dead code, which might cause some confusion. On the other hand, it might keep some automated code checkers happy. In this specific case here, I don't have a strong preference.
>
Sure, you don't need 2 checks - we can either check the length at the
start, or else check the length by looking for the return value from
snprintf, but we don't need to do both.
Given the slight complexity in determining the correct length of the printf
for the initial size check, I think I would go with the approach of *not*
checking the buffer initially and just check the snprintf return value.
That would remove any possibility of us doing an incorrect length check, as
was the case originally with this patch.
/Bruce
next prev parent reply other threads:[~2022-12-15 12:16 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-08 8:05 [PATCH 0/8] fix possible data truncation and conversion error Huisong Li
2022-12-08 8:05 ` [PATCH 1/8] telemetry: move to header to controllable range Huisong Li
2022-12-08 8:05 ` [PATCH 2/8] telemetry: add u32 telemetry data type API Huisong Li
2022-12-08 8:05 ` [PATCH 3/8] test: add test cases for u32 telemetry data API Huisong Li
2022-12-08 8:05 ` [PATCH 4/8] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-08 8:05 ` [PATCH 5/8] mempool: " Huisong Li
2022-12-08 8:05 ` [PATCH 6/8] cryptodev: fix possible data " Huisong Li
2022-12-08 8:05 ` [PATCH 7/8] mem: possible data truncation and " Huisong Li
2022-12-08 8:05 ` [PATCH 8/8] ethdev: telemetry convert capability related variable to hex Huisong Li
2022-12-08 10:55 ` Morten Brørup
2022-12-08 11:20 ` Bruce Richardson
2022-12-09 3:07 ` lihuisong (C)
2022-12-09 11:04 ` [PATCH V2 00/11] telemetry: add u32 value type and hex integer string API Huisong Li
2022-12-09 11:04 ` [PATCH V2 01/11] telemetry: move to header to controllable range Huisong Li
2022-12-09 11:04 ` [PATCH V2 02/11] telemetry: add u32 value type Huisong Li
2022-12-09 11:04 ` [PATCH V2 03/11] test: add test cases for adding u32 value API Huisong Li
2022-12-09 11:04 ` [PATCH V2 04/11] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-09 11:04 ` [PATCH V2 05/11] mempool: " Huisong Li
2022-12-09 11:04 ` [PATCH V2 06/11] cryptodev: fix possible data " Huisong Li
2022-12-09 11:04 ` [PATCH V2 07/11] mem: possible data truncation and " Huisong Li
2022-12-09 11:04 ` [PATCH V2 08/11] telemetry: refactor mapping betwween value and array type Huisong Li
2022-12-09 11:04 ` [PATCH V2 09/11] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-09 11:04 ` [PATCH V2 10/11] test: add test cases for adding hex integer values API Huisong Li
2022-12-09 11:04 ` [PATCH V2 11/11] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-09 18:24 ` [PATCH V2 00/11] telemetry: add u32 value type and hex integer string API Morten Brørup
2022-12-12 6:23 ` lihuisong (C)
2022-12-11 9:02 ` fengchengwen
2022-12-12 6:42 ` [PATCH V3 " Huisong Li
2022-12-12 6:42 ` [PATCH V3 01/11] telemetry: move to header to controllable range Huisong Li
2022-12-12 6:42 ` [PATCH V3 02/11] telemetry: add u32 value type Huisong Li
2022-12-12 6:42 ` [PATCH V3 03/11] test: add test cases for adding u32 value API Huisong Li
2022-12-12 6:42 ` [PATCH V3 04/11] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-12 6:43 ` [PATCH V3 05/11] mempool: " Huisong Li
2022-12-12 6:43 ` [PATCH V3 06/11] cryptodev: fix possible data " Huisong Li
2022-12-12 6:43 ` [PATCH V3 07/11] mem: possible data truncation and " Huisong Li
2022-12-12 6:43 ` [PATCH V3 08/11] telemetry: refactor mapping betwween value and array type Huisong Li
2022-12-12 6:43 ` [PATCH V3 09/11] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-12 6:43 ` [PATCH V3 10/11] test: add test cases for adding hex integer values API Huisong Li
2022-12-12 6:43 ` [PATCH V3 11/11] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-12 10:31 ` [PATCH V3 00/11] telemetry: add u32 value type and hex integer string API Bruce Richardson
2022-12-12 11:02 ` Morten Brørup
2022-12-12 11:20 ` Bruce Richardson
2022-12-12 12:03 ` Morten Brørup
2022-12-12 12:16 ` Bruce Richardson
2022-12-13 11:00 ` Morten Brørup
2022-12-13 17:12 ` Bruce Richardson
2022-12-13 3:02 ` lihuisong (C)
2022-12-13 10:15 ` [PATCH V4 0/9] telemetry: fix data truncation and conversion error and add hex integer API Huisong Li
2022-12-13 10:15 ` [PATCH V4 1/9] telemetry: move to header to controllable range Huisong Li
2022-12-13 17:10 ` Bruce Richardson
2022-12-14 2:44 ` lihuisong (C)
2022-12-13 10:15 ` [PATCH V4 2/9] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-13 10:15 ` [PATCH V4 3/9] mempool: " Huisong Li
2022-12-13 10:15 ` [PATCH V4 4/9] cryptodev: fix possible data " Huisong Li
2022-12-13 10:15 ` [PATCH V4 5/9] mem: possible data truncation and " Huisong Li
2022-12-13 10:15 ` [PATCH V4 6/9] telemetry: refactor mapping between value and array type Huisong Li
2022-12-13 16:57 ` Bruce Richardson
2022-12-14 2:46 ` lihuisong (C)
2022-12-13 10:15 ` [PATCH V4 7/9] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-13 17:09 ` Bruce Richardson
2022-12-14 2:44 ` lihuisong (C)
2022-12-14 7:28 ` Morten Brørup
2022-12-14 12:17 ` lihuisong (C)
2022-12-13 10:15 ` [PATCH V4 8/9] test: add test cases for adding hex integer value API Huisong Li
2022-12-13 10:15 ` [PATCH V4 9/9] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-14 12:32 ` [PATCH V5 0/8] telemetry: fix data truncation and conversion error and add hex integer API Huisong Li
2022-12-14 12:32 ` [PATCH V5 1/8] telemetry: move to header to controllable range Huisong Li
2022-12-14 12:32 ` [PATCH V5 2/8] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-14 12:32 ` [PATCH V5 3/8] mempool: " Huisong Li
2022-12-14 12:32 ` [PATCH V5 4/8] cryptodev: fix possible data " Huisong Li
2022-12-14 12:32 ` [PATCH V5 5/8] mem: possible data truncation and " Huisong Li
2022-12-14 13:00 ` Morten Brørup
2022-12-15 1:11 ` lihuisong (C)
2022-12-15 7:04 ` Morten Brørup
2022-12-15 7:56 ` lihuisong (C)
2022-12-14 12:32 ` [PATCH V5 6/8] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-14 15:38 ` Bruce Richardson
2022-12-15 1:32 ` lihuisong (C)
2022-12-14 12:32 ` [PATCH V5 7/8] test: add test cases for adding hex integer value API Huisong Li
2022-12-14 12:32 ` [PATCH V5 8/8] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-15 10:31 ` [PATCH V6 0/8] telemetry: fix data truncation and conversion error and add hex integer API Huisong Li
2022-12-15 10:31 ` [PATCH V6 1/8] telemetry: move to header to controllable range Huisong Li
2022-12-15 10:31 ` [PATCH V6 2/8] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-15 10:31 ` [PATCH V6 3/8] mempool: " Huisong Li
2022-12-15 10:31 ` [PATCH V6 4/8] cryptodev: fix possible data " Huisong Li
2022-12-15 10:31 ` [PATCH V6 5/8] mem: possible data truncation and " Huisong Li
2022-12-15 10:31 ` [PATCH V6 6/8] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-15 10:46 ` Bruce Richardson
2022-12-15 11:27 ` lihuisong (C)
2022-12-15 12:00 ` Morten Brørup
2022-12-15 12:15 ` Bruce Richardson [this message]
2022-12-15 12:24 ` Morten Brørup
2022-12-15 12:45 ` lihuisong (C)
2022-12-15 12:52 ` Morten Brørup
2022-12-15 13:08 ` Bruce Richardson
2022-12-16 1:15 ` lihuisong (C)
2022-12-15 10:31 ` [PATCH V6 7/8] test: add test cases for adding hex integer value API Huisong Li
2022-12-15 10:31 ` [PATCH V6 8/8] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-16 1:54 ` [PATCH V7 0/8] telemetry: fix data truncation and conversion error and add hex integer API Huisong Li
2022-12-16 1:54 ` [PATCH V7 1/8] telemetry: move to header to controllable range Huisong Li
2022-12-16 1:54 ` [PATCH V7 2/8] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-16 1:54 ` [PATCH V7 3/8] mempool: " Huisong Li
2022-12-16 1:54 ` [PATCH V7 4/8] cryptodev: fix possible data " Huisong Li
2022-12-16 1:54 ` [PATCH V7 5/8] mem: possible data truncation and " Huisong Li
2022-12-16 1:54 ` [PATCH V7 6/8] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-16 1:54 ` [PATCH V7 7/8] test: add test cases for adding hex integer value API Huisong Li
2022-12-16 9:31 ` Bruce Richardson
2022-12-19 7:04 ` lihuisong (C)
2022-12-16 1:54 ` [PATCH V7 8/8] ethdev: display capability values in hexadecimal format Huisong Li
2022-12-19 7:06 ` [PATCH V8 0/8] telemetry: fix data truncation and conversion error and add hex integer API Huisong Li
2022-12-19 7:06 ` [PATCH V8 1/8] telemetry: move to header to controllable range Huisong Li
2022-12-19 7:06 ` [PATCH V8 2/8] ethdev: fix possible data truncation and conversion error Huisong Li
2022-12-19 7:06 ` [PATCH V8 3/8] mempool: " Huisong Li
2022-12-19 7:06 ` [PATCH V8 4/8] cryptodev: fix possible data " Huisong Li
2022-12-19 7:06 ` [PATCH V8 5/8] mem: possible data truncation and " Huisong Li
2022-12-19 7:06 ` [PATCH V8 6/8] telemetry: support adding integer value as hexadecimal Huisong Li
2022-12-19 9:19 ` Bruce Richardson
2022-12-19 7:06 ` [PATCH V8 7/8] test: add test cases for adding hex integer value API Huisong Li
2022-12-19 7:06 ` [PATCH V8 8/8] ethdev: display capability values in hexadecimal format Huisong Li
2023-01-16 12:06 ` [PATCH V8 0/8] telemetry: fix data truncation and conversion error and add hex integer API lihuisong (C)
2023-01-30 10:39 ` lihuisong (C)
2023-02-05 20:43 ` Thomas Monjalon
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