From 63a4014236abedcc2f359bc0c7ec4029a998934b Mon Sep 17 00:00:00 2001
From: Hannah Lyons <7751607+babyhuey@users.noreply.github.com>
Date: Sat, 10 Oct 2026 17:13:10 -0400
Subject: [PATCH] feat(libkernel): implement readv and writev

---
 core/libs/prx/libkernel/File/src/Stdio.cpp | 10 ++++++++++
 core/libs/tests/GuestFileVector.cpp        | 16 ++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/core/libs/prx/libkernel/File/src/Stdio.cpp b/core/libs/prx/libkernel/File/src/Stdio.cpp
index aefd5358e..813e45767 100644
--- a/core/libs/prx/libkernel/File/src/Stdio.cpp
+++ b/core/libs/prx/libkernel/File/src/Stdio.cpp
@@ -1078,4 +1078,14 @@ int APS5_VABI fdatasync_nid_postfix(int fd) {
     return PosixResult(sceKernelFdatasync(fd));
 }
 
+int64_t APS5_VABI readv_nid_postfix(int d, const KernelIovec* iov, int iovcnt) {
+    const auto result = sceKernelReadv(d, iov, iovcnt);
+    return result < 0 ? PosixFailure(static_cast<int>(result) & 0xffff) : result;
+}
+
+int64_t APS5_VABI writev_nid_postfix(int d, const KernelIovec* iov, int iovcnt) {
+    const auto result = sceKernelWritev(d, iov, iovcnt);
+    return result < 0 ? PosixFailure(static_cast<int>(result) & 0xffff) : result;
+}
+
 }
diff --git a/core/libs/tests/GuestFileVector.cpp b/core/libs/tests/GuestFileVector.cpp
index a94009208..5bfffc521 100644
--- a/core/libs/tests/GuestFileVector.cpp
+++ b/core/libs/tests/GuestFileVector.cpp
@@ -33,6 +33,9 @@ std::int64_t APS5_VABI sceKernelRead(int, void*, std::size_t);
 std::int64_t APS5_VABI sceKernelPread(int, void*, std::size_t, std::int64_t);
 int APS5_VABI sceKernelLseek(int, std::int64_t, int);
 std::int64_t APS5_VABI sceKernelReadv(int, const GuestIovec*, int);
+std::int64_t APS5_VABI readv_nid_postfix(int, const GuestIovec*, int);
+std::int64_t APS5_VABI writev_nid_postfix(int, const GuestIovec*, int);
+int* APS5_VABI __error_nid_postfix();
 std::int64_t APS5_VABI sceKernelWritev(int, const GuestIovec*, int);
 std::int64_t APS5_VABI sceKernelPreadv(int, const GuestIovec*, int, std::int64_t);
 std::int64_t APS5_VABI sceKernelPwritev(int, const GuestIovec*, int, std::int64_t);
@@ -81,6 +84,14 @@ int main() {
     Require(sceKernelReadv(file, reads, 2) == 3);
     Require(std::memcmp(first, "789", 3) == 0);
     Require(sceKernelReadv(file, reads, 2) == 0);
+    Require(sceKernelLseek(file, 0, 0) == 0);
+    Require(readv_nid_postfix(file, reads, 2) == 7);
+    Require(std::memcmp(first, "012", 3) == 0 && std::memcmp(second, "3456", 4) == 0);
+    Require(sceKernelLseek(file, 0, 1) == 7);
+    Require(readv_nid_postfix(file, reads, 2) == 3);
+    Require(readv_nid_postfix(file, reads, 2) == 0);
+    Require(readv_nid_postfix(file, reads, -1) == -1 && *__error_nid_postfix() == 22);
+    Require(writev_nid_postfix(file, nullptr, 1) == -1 && *__error_nid_postfix() == 14);
 
     Require(sceKernelPreadv(file, reads, 2, 1) == 7);
     Require(std::memcmp(first, "123", 3) == 0 && std::memcmp(second, "4567", 4) == 0);
@@ -98,6 +109,11 @@ int main() {
     Require(sceKernelWritev(file, writes, 2) == 5);
     Require(sceKernelLseek(file, 0, 1) == 13);
     Require(Contents(path) == "01ABCDE7ABCDE");
+    GuestIovec swapped[2] = {{cde, 3}, {ab, 2}};
+    Require(sceKernelLseek(file, 8, 0) == 8 && writev_nid_postfix(file, swapped, 2) == 5);
+    Require(sceKernelLseek(file, 0, 1) == 13 && Contents(path) == "01ABCDE7CDEAB");
+    Require(sceKernelLseek(file, 8, 0) == 8 && writev_nid_postfix(file, writes, 2) == 5);
+    Require(Contents(path) == "01ABCDE7ABCDE");
 
     GuestIovec gapped[3] = {{first, 2}, {nullptr, 0}, {second, 3}};
     Require(sceKernelPreadv(file, gapped, 3, 0) == 5);