Pr2 move readv/writev to the kernel #87
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Donny9
approved these changes
Dec 26, 2024
currently, nuttx implements readv/writev on the top of read/write. while it might work for the simplest cases, it's broken by design. for example, it's impossible to make it work correctly for files which need to preserve data boundaries without allocating a single contiguous buffer. (udp socket, some character devices, etc) this change is a start of the migration to a better design. that is, implement read/write on the top of readv/writev. to avoid a single huge change, following things will NOT be done in this commit: * fix actual bugs caused by the original readv-based-on-read design. (cf. apache/nuttx#12674) * adapt filesystems/drivers to actually benefit from the new interface. (except a few trivial examples) * eventually retire the old interface. * retire read/write syscalls. implement them in libc instead. * pread/pwrite/preadv/pwritev (except the introduction of struct uio, which is a preparation to back these variations with the new interface.)
The problem has been inherited from the original libc readv/writev implementation. However, now it's exposed in more situations because this implemenation is used to back read/write as well. I expect this fixes the regressions observed on the Espressif CI. apache/nuttx#13498 (comment) Note that, even with this fix, these "compat" readv/writev implementations are still inheritedly broken. (E.g. consider that a data boundary happens to match one of iovec boundaries) However, this fix is enough for read/write, where iovcnt is always 1.
Most tools used for compliance and SBOM generation use SPDX identifiers This change brings us a step closer to an easy SBOM generation. Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
xiaoxiang781216
approved these changes
Dec 30, 2024
jasonbu
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Dec 30, 2024
… uio *)' Fix build break after open-vela#87 Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Signed-off-by: buxiasen <buxiasen@xiaomi.com>
pengxianghao21
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Dec 30, 2024
… uio *)' Fix build break after #87 Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Signed-off-by: buxiasen <buxiasen@xiaomi.com>
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