diff options
| -rw-r--r-- | drivers/firmware/efi/efi.c | 8 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/x86-stub.c | 7 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/x86-stub.h | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/unaccepted_memory.c | 64 |
4 files changed, 71 insertions, 10 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index ce20a60676f0..1974f0ad32ba 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -273,9 +273,13 @@ static __init int efivar_ssdt_load(void) if (status == EFI_NOT_FOUND) { break; } else if (status == EFI_BUFFER_TOO_SMALL) { - name = krealloc(name, name_size, GFP_KERNEL); - if (!name) + efi_char16_t *name_tmp = + krealloc(name, name_size, GFP_KERNEL); + if (!name_tmp) { + kfree(name); return -ENOMEM; + } + name = name_tmp; continue; } diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 2fee52ed335d..9d5df683f882 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -605,11 +605,8 @@ setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_s break; case EFI_UNACCEPTED_MEMORY: - if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) { - efi_warn_once( -"The system has unaccepted memory, but kernel does not support it\nConsider enabling CONFIG_UNACCEPTED_MEMORY\n"); + if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY)) continue; - } e820_type = E820_TYPE_RAM; process_unaccepted_memory(d->phys_addr, d->phys_addr + PAGE_SIZE * d->num_pages); @@ -852,6 +849,8 @@ void __noreturn efi_stub_entry(efi_handle_t handle, unsigned long kernel_entry; efi_status_t status; + boot_params_pointer = boot_params; + efi_system_table = sys_table_arg; /* Check if we were booted by the EFI firmware */ if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) diff --git a/drivers/firmware/efi/libstub/x86-stub.h b/drivers/firmware/efi/libstub/x86-stub.h index 37c5a36b9d8c..2748bca192df 100644 --- a/drivers/firmware/efi/libstub/x86-stub.h +++ b/drivers/firmware/efi/libstub/x86-stub.h @@ -2,6 +2,8 @@ #include <linux/efi.h> +extern struct boot_params *boot_params_pointer asm("boot_params"); + extern void trampoline_32bit_src(void *, bool); extern const u16 trampoline_ljmp_imm_offset; diff --git a/drivers/firmware/efi/unaccepted_memory.c b/drivers/firmware/efi/unaccepted_memory.c index 853f7dc3c21d..135278ddaf62 100644 --- a/drivers/firmware/efi/unaccepted_memory.c +++ b/drivers/firmware/efi/unaccepted_memory.c @@ -5,9 +5,17 @@ #include <linux/spinlock.h> #include <asm/unaccepted_memory.h> -/* Protects unaccepted memory bitmap */ +/* Protects unaccepted memory bitmap and accepting_list */ static DEFINE_SPINLOCK(unaccepted_memory_lock); +struct accept_range { + struct list_head list; + unsigned long start; + unsigned long end; +}; + +static LIST_HEAD(accepting_list); + /* * accept_memory() -- Consult bitmap and accept the memory if needed. * @@ -24,6 +32,7 @@ void accept_memory(phys_addr_t start, phys_addr_t end) { struct efi_unaccepted_memory *unaccepted; unsigned long range_start, range_end; + struct accept_range range, *entry; unsigned long flags; u64 unit_size; @@ -78,20 +87,67 @@ void accept_memory(phys_addr_t start, phys_addr_t end) if (end > unaccepted->size * unit_size * BITS_PER_BYTE) end = unaccepted->size * unit_size * BITS_PER_BYTE; - range_start = start / unit_size; - + range.start = start / unit_size; + range.end = DIV_ROUND_UP(end, unit_size); +retry: spin_lock_irqsave(&unaccepted_memory_lock, flags); + + /* + * Check if anybody works on accepting the same range of the memory. + * + * The check is done with unit_size granularity. It is crucial to catch + * all accept requests to the same unit_size block, even if they don't + * overlap on physical address level. + */ + list_for_each_entry(entry, &accepting_list, list) { + if (entry->end < range.start) + continue; + if (entry->start >= range.end) + continue; + + /* + * Somebody else accepting the range. Or at least part of it. + * + * Drop the lock and retry until it is complete. + */ + spin_unlock_irqrestore(&unaccepted_memory_lock, flags); + goto retry; + } + + /* + * Register that the range is about to be accepted. + * Make sure nobody else will accept it. + */ + list_add(&range.list, &accepting_list); + + range_start = range.start; for_each_set_bitrange_from(range_start, range_end, unaccepted->bitmap, - DIV_ROUND_UP(end, unit_size)) { + range.end) { unsigned long phys_start, phys_end; unsigned long len = range_end - range_start; phys_start = range_start * unit_size + unaccepted->phys_base; phys_end = range_end * unit_size + unaccepted->phys_base; + /* + * Keep interrupts disabled until the accept operation is + * complete in order to prevent deadlocks. + * + * Enabling interrupts before calling arch_accept_memory() + * creates an opportunity for an interrupt handler to request + * acceptance for the same memory. The handler will continuously + * spin with interrupts disabled, preventing other task from + * making progress with the acceptance process. + */ + spin_unlock(&unaccepted_memory_lock); + arch_accept_memory(phys_start, phys_end); + + spin_lock(&unaccepted_memory_lock); bitmap_clear(unaccepted->bitmap, range_start, len); } + + list_del(&range.list); spin_unlock_irqrestore(&unaccepted_memory_lock, flags); } |