fix(libkernel): accept SCHED_OTHER in sched_get_priority_max/min

core/libs/prx/libkernel/CMakeLists.txt

@@ -516,6 +516,16 @@ if(BUILD_TESTING)
         set_tests_properties(guest_getrusage PROPERTIES ENVIRONMENT_MODIFICATION
             "PATH=path_list_prepend:$<TARGET_FILE_DIR:libkernel>")
     endif()
+    add_test_executable(guest_sched_priority_tests ${LIBS_INCLUDE_DIR}/tests/GuestSchedPriority.cpp)
+    target_include_directories(guest_sched_priority_tests PRIVATE ${LIBS_INCLUDE_DIR})
+    target_link_libraries(guest_sched_priority_tests PRIVATE libkernel libc)
+    configure_windows_unwind(guest_sched_priority_tests)
+    add_test(NAME guest_sched_priority COMMAND guest_sched_priority_tests)
+    set_tests_properties(guest_sched_priority PROPERTIES TIMEOUT 20)
+    if(WIN32)
+        set_tests_properties(guest_sched_priority PROPERTIES ENVIRONMENT_MODIFICATION
+            "PATH=path_list_prepend:$<TARGET_FILE_DIR:libkernel>")
+    endif()
     add_test_executable(guest_kernel_error_tests ${LIBS_INCLUDE_DIR}/tests/GuestKernelErrors.cpp)
     target_include_directories(guest_kernel_error_tests PRIVATE ${LIBS_INCLUDE_DIR})
     target_link_libraries(guest_kernel_error_tests PRIVATE libkernel libc)

core/libs/prx/libkernel/System/src/Process.cpp

@@ -86,7 +86,7 @@ ProcessArguments& getProcessArguments() {
 }
 
 void validateSchedulingPolicy(int policy) {
-    if (policy != 1 && policy != 3)
+    if (policy < 1 || policy > 3)
         throw std::invalid_argument("Unsupported guest scheduling policy");
 }
 

core/libs/tests/GuestSchedPriority.cpp

@@ -0,0 +1,19 @@
+#include "prx/libc/include/general/VabiMacros.hpp"
+#include <cstdlib>
+#include <stdexcept>
+extern "C" {
+int APS5_VABI sched_get_priority_max_nid_postfix(int policy);
+int APS5_VABI sched_get_priority_min_nid_postfix(int policy);
+}
+static void Require(bool value) { if (!value) std::abort(); }
+static bool Rejects(int policy) {
+    try { sched_get_priority_max_nid_postfix(policy); } catch (const std::invalid_argument&) { return true; }
+    return false;
+}
+int main() {
+    for (int policy : {1, 2, 3}) {
+        Require(sched_get_priority_max_nid_postfix(policy) == 256);
+        Require(sched_get_priority_min_nid_postfix(policy) == 767);
+    }
+    Require(Rejects(0) && Rejects(4));
+}

docs/dev/TechnicalDebt.md

@@ -251,6 +251,7 @@ Throughout the project, every function at every stage either **does exactly what
 - [scePlayerReviewDialogOpen, scePlayerReviewDialogGetResult](../../core/libs/prx/libSceCdlgPlayerReview/Export.cpp) (libSceCdlgPlayerReview) - the PS5-only dialog has no public reference: the parameter is not read and the result is assumed to start with the 32-bit common dialog result, as `sceWebBrowserDialogGetResult` assumes
 - [sceHttpWaitRequest](../../core/libs/prx/libSceHttp/Export.cpp) (libSceHttp) - the timeout is assumed to be in microseconds and a negative timeout to wait without limit; the invalid-value error for a null handle or event array or a non-positive event count is assumed, not measured. No request is ever pending, so the call waits for the timeout and returns 0 events, and a wait without limit throws
 - [sceVideoOutAddPreVblankStartEvent](../../core/libs/prx/libSceVideoOut/src/Event.cpp) (libSceVideoOut) - how long before the vblank the console signals pre-vblank start is unknown. The event is triggered on each emulated vblank tick immediately before the vblank event, with its own count as the event data
+- [sched_get_priority_max, sched_get_priority_min](../../core/libs/prx/libkernel/System/src/Process.cpp) (libkernel) - `SCHED_OTHER` (2) reports the same 256 to 767 range as `SCHED_FIFO` and `SCHED_RR`; the console's answer is unverified. FreeBSD accepts `SCHED_OTHER` with its own range, and shadPS4 rejects it with `EINVAL`. `pthread_setschedparam` ignores the policy, so a priority taken from this range applies
 
 - [gethostbyname](../../core/libs/prx/libScePosixForWebKit/Resolver.cpp) (libScePosixForWebKit) - numeric IPv4 forms, trailing whitespace and 64-bit accumulation follow FreeBSD 11.4 [inet_aton](https://github.com/freebsd/freebsd-src/blob/releng/11.4/lib/libc/inet/inet_addr.c); clearing the resolver error on numeric success follows [fakeaddr](https://github.com/freebsd/freebsd-src/blob/releng/11.4/lib/libc/net/gethostnamadr.c). Exact PS5 behavior is unverified; hostname lookup still uses the host resolver