[PATCH 4.19 104/118] x86/efi: Allocate e820 buffer before calling efi_exit_boot_service

Greg Kroah-Hartman
2018-12-11T15:58:20Z

From: Eric Snowberg <eric.snowberg@oracle.com>

commit b84a64fad40637b1c9fa4f4dbf847a23e29e672b upstream.

The following commit:

d64934019f6c ("x86/efi: Use efi_exit_boot_services()")

introduced a regression on systems with large memory maps causing them
to hang on boot. The first "goto get_map" that was removed from
exit_boot() ensured there was enough room for the memory map when
efi_call_early(exit_boot_services) was called. This happens when
(nr_desc > ARRAY_SIZE(params->e820_table).

Chain of events:

exit_boot()
efi_exit_boot_services()
efi_get_memory_map <- at this point the mm can't grow over 8 desc
priv_func()
exit_boot_func()
allocate_e820ext() <- new mm grows over 8 desc from e820 alloc
efi_call_early(exit_boot_services) <- mm key doesn't match so retry
efi_call_early(get_memory_map) <- not enough room for new mm
system hangs

This patch allocates the e820 buffer before calling efi_exit_boot_services()
and fixes the regression.

[ mingo: minor cleanliness edits. ]

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/boot/compressed/eboot.c | 65 ++++++++++++++++++++++++---------------
1 file changed, 41 insertions(+), 24 deletions(-)

--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1,3 +1,4 @@
+
/* -----------------------------------------------------------------------
*
* Copyright 2011 Intel Corporation; author Matt Fleming
@@ -634,37 +635,54 @@ static efi_status_t alloc_e820ext(u32 nr
return status;
}

+static efi_status_t allocate_e820(struct boot_params *params,
+ struct setup_data **e820ext,
+ u32 *e820ext_size)
+{
+ unsigned long map_size, desc_size, buff_size;
+ struct efi_boot_memmap boot_map;
+ efi_memory_desc_t *map;
+ efi_status_t status;
+ __u32 nr_desc;
+
+ boot_map.map = &map;
+ boot_map.map_size = &map_size;
+ boot_map.desc_size = &desc_size;
+ boot_map.desc_ver = NULL;
+ boot_map.key_ptr = NULL;
+ boot_map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(sys_table, &boot_map);
+ if (status != EFI_SUCCESS)
+ return status;
+
+ nr_desc = buff_size / desc_size;
+
+ if (nr_desc > ARRAY_SIZE(params->e820_table)) {
+ u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);
+
+ status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
+ if (status != EFI_SUCCESS)
+ return status;
+ }
+
+ return EFI_SUCCESS;
+}
+
struct exit_boot_struct {
struct boot_params *boot_params;
struct efi_info *efi;
- struct setup_data *e820ext;
- __u32 e820ext_size;
};

static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg,
struct efi_boot_memmap *map,
void *priv)
{
- static bool first = true;
const char *signature;
__u32 nr_desc;
efi_status_t status;
struct exit_boot_struct *p = priv;

- if (first) {
- nr_desc = *map->buff_size / *map->desc_size;
- if (nr_desc > ARRAY_SIZE(p->boot_params->e820_table)) {
- u32 nr_e820ext = nr_desc -
- ARRAY_SIZE(p->boot_params->e820_table);
-
- status = alloc_e820ext(nr_e820ext, &p->e820ext,
- &p->e820ext_size);
- if (status != EFI_SUCCESS)
- return status;
- }
- first = false;
- }
-
signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
: EFI32_LOADER_SIGNATURE;
memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
@@ -687,8 +705,8 @@ static efi_status_t exit_boot(struct boo
{
unsigned long map_sz, key, desc_size, buff_size;
efi_memory_desc_t *mem_map;
- struct setup_data *e820ext;
- __u32 e820ext_size;
+ struct setup_data *e820ext = NULL;
+ __u32 e820ext_size = 0;
efi_status_t status;
__u32 desc_version;
struct efi_boot_memmap map;
@@ -702,8 +720,10 @@ static efi_status_t exit_boot(struct boo
map.buff_size = &buff_size;
priv.boot_params = boot_params;
priv.efi = &boot_params->efi_info;
- priv.e820ext = NULL;
- priv.e820ext_size = 0;
+
+ status = allocate_e820(boot_params, &e820ext, &e820ext_size);
+ if (status != EFI_SUCCESS)
+ return status;

/* Might as well exit boot services now */
status = efi_exit_boot_services(sys_table, handle, &map, &priv,
@@ -711,9 +731,6 @@ static efi_status_t exit_boot(struct boo
if (status != EFI_SUCCESS)
return status;

- e820ext = priv.e820ext;
- e820ext_size = priv.e820ext_size;
-
/* Historic? */
boot_params->alt_mem_k = 32 * 1024;