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Allow map_page call with 0 address to allocate address space

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This commit is contained in:
Justin C. Miller
2019-04-09 23:20:27 -07:00
parent 5034ffbe59
commit 070be0b005
2 changed files with 10 additions and 1 deletions
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8
src/kernel/page_manager.cpp
View File

@@ -247,6 +247,11 @@ page_manager::free_table_pages(void *pages, size_t count)
void *
page_manager::map_pages(uintptr_t address, size_t count, bool user, page_table *pml4)
{
if (!address) {
kassert(!user, "Cannot call map_pages with 0 address for user mapping");
address = m_addrs.allocate(count * frame_size);
}
void *ret = reinterpret_cast<void *>(address);
if (!pml4) pml4 = get_pml4();
@@ -338,6 +343,9 @@ page_manager::unmap_pages(void* address, size_t count, page_table *pml4)
{
if (!pml4) pml4 = get_pml4();
page_out(pml4, reinterpret_cast<uintptr_t>(address), count, true);
if (address >= kernel_offset) {
m_addrs.free(address, count);
}
}
void

3
src/kernel/page_manager.h
View File

@@ -66,7 +66,8 @@ public:
page_table_indices index = {});
/// Allocate and map pages into virtual memory.
/// \arg address The virtual address at which to map the pages
/// \arg address The virtual address at which to map the pages, or zero
/// for any free kernel space.
/// \arg count The number of pages to map
/// \arg user True is this memory is user-accessible
/// \arg pml4 The pml4 to map into - null for the current one