[PATCH v2 2/4] efi: Add tracking for dynamically allocated memmaps

From: Dan Williams
Date: Tue Dec 31 2019 - 17:20:45 EST


In preparation for fixing efi_memmap_alloc() leaks, add support for
recording whether the memmap was dynamically allocated from slab,
memblock, or is the original physical memmap provided by the platform.

Cc: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/x86/platform/efi/efi.c | 2 +-
arch/x86/platform/efi/quirks.c | 11 ++++++-----
drivers/firmware/efi/fake_mem.c | 5 +++--
drivers/firmware/efi/memmap.c | 16 ++++++++++------
include/linux/efi.h | 8 ++++++--
5 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 38d44f36d5ed..7086afbb84fd 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -333,7 +333,7 @@ static void __init efi_clean_memmap(void)
u64 size = efi.memmap.nr_map - n_removal;

pr_warn("Removing %d invalid memory map entries.\n", n_removal);
- efi_memmap_install(efi.memmap.phys_map, size);
+ efi_memmap_install(efi.memmap.phys_map, size, 0);
}
}

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index f8f0220b6a66..4a71c790f9c3 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -244,6 +244,7 @@ EXPORT_SYMBOL_GPL(efi_query_variable_store);
void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
{
phys_addr_t new_phys, new_size;
+ unsigned long flags = 0;
struct efi_mem_range mr;
efi_memory_desc_t md;
int num_entries;
@@ -272,8 +273,7 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
num_entries += efi.memmap.nr_map;

new_size = efi.memmap.desc_size * num_entries;
-
- new_phys = efi_memmap_alloc(num_entries);
+ new_phys = efi_memmap_alloc(num_entries, &flags);
if (!new_phys) {
pr_err("Could not allocate boot services memmap\n");
return;
@@ -288,7 +288,7 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
efi_memmap_insert(&efi.memmap, new, &mr);
early_memunmap(new, new_size);

- efi_memmap_install(new_phys, num_entries);
+ efi_memmap_install(new_phys, num_entries, flags);
e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
e820__update_table(e820_table);
}
@@ -408,6 +408,7 @@ static void __init efi_unmap_pages(efi_memory_desc_t *md)
void __init efi_free_boot_services(void)
{
phys_addr_t new_phys, new_size;
+ unsigned long flags = 0;
efi_memory_desc_t *md;
int num_entries = 0;
void *new, *new_md;
@@ -463,7 +464,7 @@ void __init efi_free_boot_services(void)
return;

new_size = efi.memmap.desc_size * num_entries;
- new_phys = efi_memmap_alloc(num_entries);
+ new_phys = efi_memmap_alloc(num_entries, &flags);
if (!new_phys) {
pr_err("Failed to allocate new EFI memmap\n");
return;
@@ -493,7 +494,7 @@ void __init efi_free_boot_services(void)

memunmap(new);

- if (efi_memmap_install(new_phys, num_entries)) {
+ if (efi_memmap_install(new_phys, num_entries, flags)) {
pr_err("Could not install new EFI memmap\n");
return;
}
diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
index bb9fc70d0cfa..7e53e5520548 100644
--- a/drivers/firmware/efi/fake_mem.c
+++ b/drivers/firmware/efi/fake_mem.c
@@ -39,6 +39,7 @@ void __init efi_fake_memmap(void)
int new_nr_map = efi.memmap.nr_map;
efi_memory_desc_t *md;
phys_addr_t new_memmap_phy;
+ unsigned long flags = 0;
void *new_memmap;
int i;

@@ -55,7 +56,7 @@ void __init efi_fake_memmap(void)
}

/* allocate memory for new EFI memmap */
- new_memmap_phy = efi_memmap_alloc(new_nr_map);
+ new_memmap_phy = efi_memmap_alloc(new_nr_map, &flags);
if (!new_memmap_phy)
return;

@@ -73,7 +74,7 @@ void __init efi_fake_memmap(void)
/* swap into new EFI memmap */
early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);

- efi_memmap_install(new_memmap_phy, new_nr_map);
+ efi_memmap_install(new_memmap_phy, new_nr_map, flags);

/* print new EFI memmap */
efi_print_memmap();
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 813674ef9000..2b81ee6858a9 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -32,6 +32,7 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
/**
* efi_memmap_alloc - Allocate memory for the EFI memory map
* @num_entries: Number of entries in the allocated map.
+ * @flags: Late map, memblock alloc, slab alloc flags
*
* Depending on whether mm_init() has already been invoked or not,
* either memblock or "normal" page allocation is used.
@@ -39,20 +40,23 @@ static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
* Returns the physical address of the allocated memory map on
* success, zero on failure.
*/
-phys_addr_t __init efi_memmap_alloc(unsigned int num_entries)
+phys_addr_t __init efi_memmap_alloc(unsigned int num_entries, unsigned long *flags)
{
unsigned long size = num_entries * efi.memmap.desc_size;

- if (slab_is_available())
+ if (slab_is_available()) {
+ *flags |= EFI_MEMMAP_SLAB;
return __efi_memmap_alloc_late(size);
+ }

+ *flags |= EFI_MEMMAP_MEMBLOCK;
return __efi_memmap_alloc_early(size);
}

/**
* __efi_memmap_init - Common code for mapping the EFI memory map
* @data: EFI memory map data
- * @flags: Use early or late mapping function?
+ * @flags: Use early or late mapping function, and allocator
*
* This function takes care of figuring out which function to use to
* map the EFI memory map in efi.memmap based on how far into the boot
@@ -192,10 +196,10 @@ int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size)
*
* Returns zero on success, a negative error code on failure.
*/
-int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map)
+int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map,
+ unsigned long flags)
{
struct efi_memory_map_data data;
- unsigned long flags;

efi_memmap_unmap();

@@ -203,7 +207,7 @@ int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map)
data.size = efi.memmap.desc_size * nr_map;
data.desc_version = efi.memmap.desc_version;
data.desc_size = efi.memmap.desc_size;
- flags = efi.memmap.flags & EFI_MEMMAP_LATE;
+ flags |= efi.memmap.flags & EFI_MEMMAP_LATE;

return __efi_memmap_init(&data, flags);
}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index b8e930f5ff77..fa2668a992ae 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -796,6 +796,8 @@ struct efi_memory_map {
unsigned long desc_version;
unsigned long desc_size;
#define EFI_MEMMAP_LATE (1UL << 0)
+#define EFI_MEMMAP_MEMBLOCK (1UL << 1)
+#define EFI_MEMMAP_SLAB (1UL << 2)
unsigned long flags;
};

@@ -1057,11 +1059,13 @@ static inline efi_status_t efi_query_variable_store(u32 attributes,
#endif
extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);

-extern phys_addr_t __init efi_memmap_alloc(unsigned int num_entries);
+extern phys_addr_t __init efi_memmap_alloc(unsigned int num_entries,
+ unsigned long *flags);
extern int __init efi_memmap_init_early(struct efi_memory_map_data *data);
extern int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size);
extern void __init efi_memmap_unmap(void);
-extern int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map);
+extern int __init efi_memmap_install(phys_addr_t addr, unsigned int nr_map,
+ unsigned long flags);
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,