From 6346e288ad54416481972f22b67dc5274968934a Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Mon, 2 Dec 2024 03:54:11 +0200
Subject: [PATCH] LibC: Implement getrlimit

---
 kernel/include/kernel/Thread.h            |  5 +--
 kernel/kernel/Thread.cpp                  |  6 ++--
 userspace/libraries/LibC/sys/resource.cpp | 43 +++++++++++++++++++++++
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/kernel/include/kernel/Thread.h b/kernel/include/kernel/Thread.h
index af38dcc1d3..02f3567525 100644
--- a/kernel/include/kernel/Thread.h
+++ b/kernel/include/kernel/Thread.h
@@ -30,6 +30,9 @@ namespace Kernel
 			Terminated,
 		};
 
+		static constexpr size_t kernel_stack_size    { PAGE_SIZE * 8 };
+		static constexpr size_t userspace_stack_size { PAGE_SIZE * 128 };
+
 	public:
 		static BAN::ErrorOr<Thread*> create_kernel(entry_t, void*, Process*);
 		static BAN::ErrorOr<Thread*> create_userspace(Process*, PageTable&);
@@ -103,8 +106,6 @@ namespace Kernel
 		//       {kernel,userspace}_stack has to be destroyed before page table
 		BAN::UniqPtr<PageTable>    m_keep_alive_page_table;
 
-		static constexpr size_t    m_kernel_stack_size    { PAGE_SIZE * 8 };
-		static constexpr size_t    m_userspace_stack_size { PAGE_SIZE * 128 };
 		BAN::UniqPtr<VirtualRange> m_kernel_stack;
 		BAN::UniqPtr<VirtualRange> m_userspace_stack;
 		const pid_t                m_tid                  { 0 };
diff --git a/kernel/kernel/Thread.cpp b/kernel/kernel/Thread.cpp
index ef63b34ddb..38ed8a93b4 100644
--- a/kernel/kernel/Thread.cpp
+++ b/kernel/kernel/Thread.cpp
@@ -64,7 +64,7 @@ namespace Kernel
 			PageTable::kernel(),
 			KERNEL_OFFSET,
 			~(uintptr_t)0,
-			m_kernel_stack_size,
+			kernel_stack_size,
 			PageTable::Flags::ReadWrite | PageTable::Flags::Present,
 			true
 		));
@@ -104,7 +104,7 @@ namespace Kernel
 		thread->m_kernel_stack = TRY(VirtualRange::create_to_vaddr_range(
 			page_table,
 			0x300000, KERNEL_OFFSET,
-			m_kernel_stack_size,
+			kernel_stack_size,
 			PageTable::Flags::ReadWrite | PageTable::Flags::Present,
 			true
 		));
@@ -112,7 +112,7 @@ namespace Kernel
 		thread->m_userspace_stack = TRY(VirtualRange::create_to_vaddr_range(
 			page_table,
 			0x300000, KERNEL_OFFSET,
-			m_userspace_stack_size,
+			userspace_stack_size,
 			PageTable::Flags::UserSupervisor | PageTable::Flags::ReadWrite | PageTable::Flags::Present,
 			true
 		));
diff --git a/userspace/libraries/LibC/sys/resource.cpp b/userspace/libraries/LibC/sys/resource.cpp
index aca16eae2c..1ab4b1f56a 100644
--- a/userspace/libraries/LibC/sys/resource.cpp
+++ b/userspace/libraries/LibC/sys/resource.cpp
@@ -1,7 +1,50 @@
 #include <BAN/Assert.h>
+#include <BAN/Limits.h>
+
+#include <kernel/Thread.h>
+
 #include <errno.h>
+#include <limits.h>
 #include <sys/resource.h>
 
+int getrlimit(int resource, struct rlimit* rlp)
+{
+	switch (resource)
+	{
+		case RLIMIT_CORE:
+			rlp->rlim_cur = 0;
+			rlp->rlim_max = 0;
+			return 0;
+		case RLIMIT_CPU:
+			rlp->rlim_cur = BAN::numeric_limits<rlim_t>::max();
+			rlp->rlim_max = BAN::numeric_limits<rlim_t>::max();
+			return 0;
+		case RLIMIT_DATA:
+			rlp->rlim_cur = BAN::numeric_limits<rlim_t>::max();
+			rlp->rlim_max = BAN::numeric_limits<rlim_t>::max();
+			return 0;
+		case RLIMIT_FSIZE:
+			rlp->rlim_cur = BAN::numeric_limits<rlim_t>::max();
+			rlp->rlim_max = BAN::numeric_limits<rlim_t>::max();
+			return 0;
+		case RLIMIT_NOFILE:
+			rlp->rlim_cur = OPEN_MAX;
+			rlp->rlim_max = OPEN_MAX;
+			return 0;
+		case RLIMIT_STACK:
+			rlp->rlim_cur = Kernel::Thread::userspace_stack_size;
+			rlp->rlim_max = Kernel::Thread::userspace_stack_size;
+			return 0;
+		case RLIMIT_AS:
+			rlp->rlim_cur = BAN::numeric_limits<rlim_t>::max();
+			rlp->rlim_max = BAN::numeric_limits<rlim_t>::max();
+			return 0;
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
 int getrusage(int who, struct rusage* r_usage)
 {
 	if (who != RUSAGE_CHILDREN && who != RUSAGE_SELF)