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 <lihuis...@huawei.com>
Acked-by: Morten Brørup <m...@smartsharesystems.com>
Acked-by: Chengwen Feng <fengcheng...@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,
+ 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;
+ if (display_bitwidth != 0) {
+ sprintf(format, "0x%%0%u" PRIx64, spec_hex_width);
+ sprintf(buf, format, val);
+ } else {
+ sprintf(buf, "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?
Thanks,
/Bruce
.
