[GIT PULL] EFI fixes

From: Ingo Molnar
Date: Sun Jan 15 2017 - 04:53:28 EST

Linus,

Please pull the latest efi-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git efi-urgent-for-linus

# HEAD: 0100a3e67a9cef64d72cd3a1da86f3ddbee50363 efi/x86: Prune invalid memory map entries and fix boot regression

A number of regression fixes:

- Fix a boot hang on machines that have somewhat unusual memory map entries of
phys_addr=0x0 num_pages=0, which broke due to a recent commit. This commit got
cherry-picked from the v4.11 queue because the bug is affecting real machines.

- Fix a boot hang also reported by KASAN, caused by incorrect init ordering
introduced by a recent optimization.

- Fix a recent robustification fix to allocate_new_fdt_and_exit_boot() that
introduced an invalid assumption. Neither bugs were seen in the wild AFAIK.

Thanks,

Ingo

------------------>
Ard Biesheuvel (1):
efi/libstub/arm*: Pass latest memory map to the kernel

Nicolai Stange (1):
x86/efi: Don't allocate memmap through memblock after mm_init()

Peter Jones (1):
efi/x86: Prune invalid memory map entries and fix boot regression


arch/x86/platform/efi/efi.c | 66 ++++++++++++++++++++++++++
arch/x86/platform/efi/quirks.c | 4 +-
drivers/firmware/efi/fake_mem.c | 3 +-
drivers/firmware/efi/libstub/efistub.h | 8 ----
drivers/firmware/efi/libstub/fdt.c | 87 ++++++++++++++++++++++------------
drivers/firmware/efi/memmap.c | 38 +++++++++++++++
include/linux/efi.h | 2 +
7 files changed, 165 insertions(+), 43 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 936a488d6cf6..274dfc481849 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -210,6 +210,70 @@ int __init efi_memblock_x86_reserve_range(void)
return 0;
}

+#define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
+#define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
+#define U64_HIGH_BIT (~(U64_MAX >> 1))
+
+static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
+{
+ u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
+ u64 end_hi = 0;
+ char buf[64];
+
+ if (md->num_pages == 0) {
+ end = 0;
+ } else if (md->num_pages > EFI_PAGES_MAX ||
+ EFI_PAGES_MAX - md->num_pages <
+ (md->phys_addr >> EFI_PAGE_SHIFT)) {
+ end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
+ >> OVERFLOW_ADDR_SHIFT;
+
+ if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
+ end_hi += 1;
+ } else {
+ return true;
+ }
+
+ pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
+
+ if (end_hi) {
+ pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
+ i, efi_md_typeattr_format(buf, sizeof(buf), md),
+ md->phys_addr, end_hi, end);
+ } else {
+ pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
+ i, efi_md_typeattr_format(buf, sizeof(buf), md),
+ md->phys_addr, end);
+ }
+ return false;
+}
+
+static void __init efi_clean_memmap(void)
+{
+ efi_memory_desc_t *out = efi.memmap.map;
+ const efi_memory_desc_t *in = out;
+ const efi_memory_desc_t *end = efi.memmap.map_end;
+ int i, n_removal;
+
+ for (i = n_removal = 0; in < end; i++) {
+ if (efi_memmap_entry_valid(in, i)) {
+ if (out != in)
+ memcpy(out, in, efi.memmap.desc_size);
+ out = (void *)out + efi.memmap.desc_size;
+ } else {
+ n_removal++;
+ }
+ in = (void *)in + efi.memmap.desc_size;
+ }
+
+ if (n_removal > 0) {
+ 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);
+ }
+}
+
void __init efi_print_memmap(void)
{
efi_memory_desc_t *md;
@@ -472,6 +536,8 @@ void __init efi_init(void)
}
}

+ efi_clean_memmap();
+
if (efi_enabled(EFI_DBG))
efi_print_memmap();
}
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 10aca63a50d7..30031d5293c4 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -214,7 +214,7 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)

new_size = efi.memmap.desc_size * num_entries;

- new_phys = memblock_alloc(new_size, 0);
+ new_phys = efi_memmap_alloc(num_entries);
if (!new_phys) {
pr_err("Could not allocate boot services memmap\n");
return;
@@ -355,7 +355,7 @@ void __init efi_free_boot_services(void)
}

new_size = efi.memmap.desc_size * num_entries;
- new_phys = memblock_alloc(new_size, 0);
+ new_phys = efi_memmap_alloc(num_entries);
if (!new_phys) {
pr_err("Failed to allocate new EFI memmap\n");
return;
diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
index 520a40e5e0e4..6c7d60c239b5 100644
--- a/drivers/firmware/efi/fake_mem.c
+++ b/drivers/firmware/efi/fake_mem.c
@@ -71,8 +71,7 @@ void __init efi_fake_memmap(void)
}

/* allocate memory for new EFI memmap */
- new_memmap_phy = memblock_alloc(efi.memmap.desc_size * new_nr_map,
- PAGE_SIZE);
+ new_memmap_phy = efi_memmap_alloc(new_nr_map);
if (!new_memmap_phy)
return;

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index b98824e3800a..0e2a96b12cb3 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -39,14 +39,6 @@ efi_status_t efi_file_close(void *handle);

unsigned long get_dram_base(efi_system_table_t *sys_table_arg);

-efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
- unsigned long orig_fdt_size,
- void *fdt, int new_fdt_size, char *cmdline_ptr,
- u64 initrd_addr, u64 initrd_size,
- efi_memory_desc_t *memory_map,
- unsigned long map_size, unsigned long desc_size,
- u32 desc_ver);
-
efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
void *handle,
unsigned long *new_fdt_addr,
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index a6a93116a8f0..921dfa047202 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -16,13 +16,10 @@

#include "efistub.h"

-efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
- unsigned long orig_fdt_size,
- void *fdt, int new_fdt_size, char *cmdline_ptr,
- u64 initrd_addr, u64 initrd_size,
- efi_memory_desc_t *memory_map,
- unsigned long map_size, unsigned long desc_size,
- u32 desc_ver)
+static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
+ unsigned long orig_fdt_size,
+ void *fdt, int new_fdt_size, char *cmdline_ptr,
+ u64 initrd_addr, u64 initrd_size)
{
int node, num_rsv;
int status;
@@ -101,25 +98,23 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
if (status)
goto fdt_set_fail;

- fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map);
+ fdt_val64 = U64_MAX; /* placeholder */
status = fdt_setprop(fdt, node, "linux,uefi-mmap-start",
&fdt_val64, sizeof(fdt_val64));
if (status)
goto fdt_set_fail;

- fdt_val32 = cpu_to_fdt32(map_size);
+ fdt_val32 = U32_MAX; /* placeholder */
status = fdt_setprop(fdt, node, "linux,uefi-mmap-size",
&fdt_val32, sizeof(fdt_val32));
if (status)
goto fdt_set_fail;

- fdt_val32 = cpu_to_fdt32(desc_size);
status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size",
&fdt_val32, sizeof(fdt_val32));
if (status)
goto fdt_set_fail;

- fdt_val32 = cpu_to_fdt32(desc_ver);
status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver",
&fdt_val32, sizeof(fdt_val32));
if (status)
@@ -148,6 +143,43 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
return EFI_LOAD_ERROR;
}

+static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
+{
+ int node = fdt_path_offset(fdt, "/chosen");
+ u64 fdt_val64;
+ u32 fdt_val32;
+ int err;
+
+ if (node < 0)
+ return EFI_LOAD_ERROR;
+
+ fdt_val64 = cpu_to_fdt64((unsigned long)*map->map);
+ err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-start",
+ &fdt_val64, sizeof(fdt_val64));
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(*map->map_size);
+ err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-size",
+ &fdt_val32, sizeof(fdt_val32));
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(*map->desc_size);
+ err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-size",
+ &fdt_val32, sizeof(fdt_val32));
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(*map->desc_ver);
+ err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-ver",
+ &fdt_val32, sizeof(fdt_val32));
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ return EFI_SUCCESS;
+}
+
#ifndef EFI_FDT_ALIGN
#define EFI_FDT_ALIGN EFI_PAGE_SIZE
#endif
@@ -243,20 +275,10 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
goto fail;
}

- /*
- * Now that we have done our final memory allocation (and free)
- * we can get the memory map key needed for
- * exit_boot_services().
- */
- status = efi_get_memory_map(sys_table, &map);
- if (status != EFI_SUCCESS)
- goto fail_free_new_fdt;
-
status = update_fdt(sys_table,
(void *)fdt_addr, fdt_size,
(void *)*new_fdt_addr, new_fdt_size,
- cmdline_ptr, initrd_addr, initrd_size,
- memory_map, map_size, desc_size, desc_ver);
+ cmdline_ptr, initrd_addr, initrd_size);

/* Succeeding the first time is the expected case. */
if (status == EFI_SUCCESS)
@@ -266,20 +288,16 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
/*
* We need to allocate more space for the new
* device tree, so free existing buffer that is
- * too small. Also free memory map, as we will need
- * to get new one that reflects the free/alloc we do
- * on the device tree buffer.
+ * too small.
*/
efi_free(sys_table, new_fdt_size, *new_fdt_addr);
- sys_table->boottime->free_pool(memory_map);
new_fdt_size += EFI_PAGE_SIZE;
} else {
pr_efi_err(sys_table, "Unable to construct new device tree.\n");
- goto fail_free_mmap;
+ goto fail_free_new_fdt;
}
}

- sys_table->boottime->free_pool(memory_map);
priv.runtime_map = runtime_map;
priv.runtime_entry_count = &runtime_entry_count;
status = efi_exit_boot_services(sys_table, handle, &map, &priv,
@@ -288,6 +306,16 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
if (status == EFI_SUCCESS) {
efi_set_virtual_address_map_t *svam;

+ status = update_fdt_memmap((void *)*new_fdt_addr, &map);
+ if (status != EFI_SUCCESS) {
+ /*
+ * The kernel won't get far without the memory map, but
+ * may still be able to print something meaningful so
+ * return success here.
+ */
+ return EFI_SUCCESS;
+ }
+
/* Install the new virtual address map */
svam = sys_table->runtime->set_virtual_address_map;
status = svam(runtime_entry_count * desc_size, desc_size,
@@ -319,9 +347,6 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,

pr_efi_err(sys_table, "Exit boot services failed.\n");

-fail_free_mmap:
- sys_table->boottime->free_pool(memory_map);
-
fail_free_new_fdt:
efi_free(sys_table, new_fdt_size, *new_fdt_addr);

diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index f03ddecd232b..78686443cb37 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -9,6 +9,44 @@
#include <linux/efi.h>
#include <linux/io.h>
#include <asm/early_ioremap.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+
+static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
+{
+ return memblock_alloc(size, 0);
+}
+
+static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
+{
+ unsigned int order = get_order(size);
+ struct page *p = alloc_pages(GFP_KERNEL, order);
+
+ if (!p)
+ return 0;
+
+ return PFN_PHYS(page_to_pfn(p));
+}
+
+/**
+ * efi_memmap_alloc - Allocate memory for the EFI memory map
+ * @num_entries: Number of entries in the allocated map.
+ *
+ * Depending on whether mm_init() has already been invoked or not,
+ * either memblock or "normal" page allocation is used.
+ *
+ * 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)
+{
+ unsigned long size = num_entries * efi.memmap.desc_size;
+
+ if (slab_is_available())
+ return __efi_memmap_alloc_late(size);
+
+ return __efi_memmap_alloc_early(size);
+}

/**
* __efi_memmap_init - Common code for mapping the EFI memory map
diff --git a/include/linux/efi.h b/include/linux/efi.h
index a07a476178cd..5b1af30ece55 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -103,6 +103,7 @@ typedef struct {

#define EFI_PAGE_SHIFT 12
#define EFI_PAGE_SIZE (1UL << EFI_PAGE_SHIFT)
+#define EFI_PAGES_MAX (U64_MAX >> EFI_PAGE_SHIFT)

typedef struct {
u32 type;
@@ -950,6 +951,7 @@ 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 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);