Commit-ID: b84a64fad40637b1c9fa4f4dbf847a23e29e672b Gitweb: https://git.kernel.org/tip/b84a64fad40637b1c9fa4f4dbf847a23e29e672b Author: Eric Snowberg eric.snowberg@oracle.com AuthorDate: Thu, 29 Nov 2018 18:12:20 +0100 Committer: Ingo Molnar mingo@kernel.org CommitDate: Fri, 30 Nov 2018 08:30:07 +0100

x86/efi: Allocate e820 buffer before calling efi_exit_boot_service

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

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index 8b4c5e001157..544ac4fafd11 100644 --- 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_desc, struct setup_data **e820ext, 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 boot_params *boot_params, void *handle) { 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 boot_params *boot_params, void *handle) 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 boot_params *boot_params, void *handle) if (status != EFI_SUCCESS) return status;

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