[PATCH 1/4] efi/x86: make efi_memmap_reserve only insert into boot mem areas

[Dave Young]

There are memory ranges like below when I testing early efi_mem_reserve:

efi: mem62: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
efi: mem63: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
efi: mem64: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
efi: mem65: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
efi: mem66: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
efi: mem67: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)

So efi_memmap_insert will run into inserting same region multiple times,
also because efi_memmap_insert does not consider the duplicate ranges it will
cause memmap buffer overflow due to the size is pre-calculated, and kernel boot
fail with a panic.  We did not detect such issue because current users of
efi_mem_insert do it very late after switching to virtual mode, at that time
the new cooked efi.memmap contains only runtime needed memory ranges.

efi_mem_reserve cares only about boot services regions and maybe loader areas.
So add a new argument to efi_memmap_insert for this purpose.
 
Later patches depend on this one for moving bgrt reservation to early code.

Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
---
 arch/x86/platform/efi/quirks.c  |    2 +-
 drivers/firmware/efi/fake_mem.c |    3 ++-
 drivers/firmware/efi/memmap.c   |    8 +++++++-
 include/linux/efi.h             |    4 ++--
 4 files changed, 12 insertions(+), 5 deletions(-)

--- linux-x86.orig/drivers/firmware/efi/memmap.c
+++ linux-x86/drivers/firmware/efi/memmap.c
@@ -213,7 +213,7 @@ int __init efi_memmap_split_count(efi_me
  * to see how large @buf needs to be.
  */
 void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
-			      struct efi_mem_range *mem)
+			      struct efi_mem_range *mem, bool boot_only)
 {
 	u64 m_start, m_end, m_attr;
 	efi_memory_desc_t *md;
@@ -246,6 +246,12 @@ void __init efi_memmap_insert(struct efi
 		start = md->phys_addr;
 		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
 
+		if (boot_only && !(md->type == EFI_LOADER_DATA ||
+		    md->type == EFI_LOADER_CODE ||
+		    md->type == EFI_BOOT_SERVICES_CODE ||
+		    md->type == EFI_BOOT_SERVICES_DATA))
+			continue;
+
 		if (m_start <= start && end <= m_end)
 			md->attribute |= m_attr;
 
--- linux-x86.orig/arch/x86/platform/efi/quirks.c
+++ linux-x86/arch/x86/platform/efi/quirks.c
@@ -226,7 +226,7 @@ void __init efi_arch_mem_reserve(phys_ad
 		return;
 	}
 
-	efi_memmap_insert(&efi.memmap, new, &mr);
+	efi_memmap_insert(&efi.memmap, new, &mr, true);
 	early_memunmap(new, new_size);
 
 	efi_memmap_install(new_phys, num_entries);
--- linux-x86.orig/drivers/firmware/efi/fake_mem.c
+++ linux-x86/drivers/firmware/efi/fake_mem.c
@@ -85,7 +85,8 @@ void __init efi_fake_memmap(void)
 	}
 
 	for (i = 0; i < nr_fake_mem; i++)
-		efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);
+		efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i],
+				  false);
 
 	/* swap into new EFI memmap */
 	early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);
--- linux-x86.orig/include/linux/efi.h
+++ linux-x86/include/linux/efi.h
@@ -957,8 +957,8 @@ extern int __init efi_memmap_install(phy
 extern int __init efi_memmap_split_count(efi_memory_desc_t *md,
 					 struct range *range);
 extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap,
-				     void *buf, struct efi_mem_range *mem);
-
+				     void *buf, struct efi_mem_range *mem,
+				     bool boot_only);
 extern int efi_config_init(efi_config_table_type_t *arch_tables);
 #ifdef CONFIG_EFI_ESRT
 extern void __init efi_esrt_init(void);