From e7fb70b05c15166ff440e1d6f0bed3b5d555d146 Mon Sep 17 00:00:00 2001 From: Brian Gianforcaro Date: Fri, 13 Aug 2021 01:32:48 -0700 Subject: [PATCH] Kernel: Allow kmalloc(..) / kmalloc_aligned(..) to return nullptr Now that we have a significant amount of code paths handling OOM, lets enable kmalloc and friends to actually return nullptr. This way we can start stressing these paths and validating all of they work as expected. --- Kernel/Heap/kmalloc.cpp | 3 --- Kernel/Heap/kmalloc.h | 6 ++++-- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/Kernel/Heap/kmalloc.cpp b/Kernel/Heap/kmalloc.cpp index 538f791754..8ee983c321 100644 --- a/Kernel/Heap/kmalloc.cpp +++ b/Kernel/Heap/kmalloc.cpp @@ -255,9 +255,6 @@ void* kmalloc(size_t size) } void* ptr = g_kmalloc_global->m_heap.allocate(size); - if (!ptr) { - PANIC("kmalloc: Out of memory (requested size: {})", size); - } Thread* current_thread = Thread::current(); if (!current_thread) diff --git a/Kernel/Heap/kmalloc.h b/Kernel/Heap/kmalloc.h index f05766ff21..f7af78577b 100644 --- a/Kernel/Heap/kmalloc.h +++ b/Kernel/Heap/kmalloc.h @@ -75,14 +75,16 @@ void operator delete(void* ptr, size_t, std::align_val_t) noexcept; void operator delete[](void* ptrs) noexcept DISALLOW("All deletes in the kernel should have a known size."); void operator delete[](void* ptr, size_t) noexcept; -[[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] void* kmalloc(size_t); +[[gnu::malloc, gnu::alloc_size(1)]] void* kmalloc(size_t); template -[[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] inline void* kmalloc_aligned(size_t size) +[[gnu::malloc, gnu::alloc_size(1)]] inline void* kmalloc_aligned(size_t size) { static_assert(ALIGNMENT > sizeof(ptrdiff_t)); static_assert(ALIGNMENT <= 4096); void* ptr = kmalloc(size + ALIGNMENT + sizeof(ptrdiff_t)); + if (ptr == nullptr) + return ptr; size_t max_addr = (size_t)ptr + ALIGNMENT; void* aligned_ptr = (void*)(max_addr - (max_addr % ALIGNMENT)); ((ptrdiff_t*)aligned_ptr)[-1] = (ptrdiff_t)((u8*)aligned_ptr - (u8*)ptr);