| Message ID | 20181114175544.12860-1-ard.biesheuvel@linaro.org |
|---|---|
| Headers | show |
| Series | EFI fixes for v4.20 | expand |
Hi Ard, On 11/14/2018 11:55 AM, Ard Biesheuvel wrote: > Currently, efi_mem_reserve_persistent() may not be called from atomic > context, since both the kmalloc() call and the memremap() call may > sleep. > > The kmalloc() call is easy enough to fix, but the memremap() call > needs to be moved into an init hook since we cannot control the > memory allocation behavior of memremap() at the call site. So, at first glance this looks correct until I noticed that its_cpu_init_lpis() is being called before the early_initcalls are run. This results in the WARN_ON triggering with the following backtrace: [ 0.000000] its_cpu_init_lpis+0x1d4/0x2e0 [ 0.000000] its_cpu_init+0x78/0x1b4 [ 0.000000] gic_init_bases+0x2c4/0x2e0 [ 0.000000] gic_acpi_init+0x158/0x270 [ 0.000000] acpi_match_madt+0x4c/0x84 [ 0.000000] acpi_table_parse_entries_array+0x140/0x218 [ 0.000000] acpi_table_parse_entries+0x70/0x98 [ 0.000000] acpi_table_parse_madt+0x40/0x50 [ 0.000000] __acpi_probe_device_table+0x88/0xe0 [ 0.000000] irqchip_init+0x38/0x40 [ 0.000000] init_IRQ+0xfc/0x130 [ 0.000000] start_kernel+0x344/0x4cc due to the efi_memreserve_root not yet being set. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > drivers/firmware/efi/efi.c | 31 +++++++++++++++++++------------ > 1 file changed, 19 insertions(+), 12 deletions(-) > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index 72a4da76d274..fad7c62cfc0e 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -967,36 +967,43 @@ bool efi_is_table_address(unsigned long phys_addr) > } > > static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock); > +static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init; > > int efi_mem_reserve_persistent(phys_addr_t addr, u64 size) > { > - struct linux_efi_memreserve *rsv, *parent; > + struct linux_efi_memreserve *rsv; > > - if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) > + if (!efi_memreserve_root) > return -ENODEV; > > - rsv = kmalloc(sizeof(*rsv), GFP_KERNEL); > + rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC); > if (!rsv) > return -ENOMEM; > > - parent = memremap(efi.mem_reserve, sizeof(*rsv), MEMREMAP_WB); > - if (!parent) { > - kfree(rsv); > - return -ENOMEM; > - } > - > rsv->base = addr; > rsv->size = size; > > spin_lock(&efi_mem_reserve_persistent_lock); > - rsv->next = parent->next; > - parent->next = __pa(rsv); > + rsv->next = efi_memreserve_root->next; > + efi_memreserve_root->next = __pa(rsv); > spin_unlock(&efi_mem_reserve_persistent_lock); > > - memunmap(parent); > + return 0; > +} > > +static int __init efi_memreserve_root_init(void) > +{ > + if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) > + return -ENODEV; > + > + efi_memreserve_root = memremap(efi.mem_reserve, > + sizeof(*efi_memreserve_root), > + MEMREMAP_WB); > + if (!efi_memreserve_root) > + return -ENOMEM; > return 0; > } > +early_initcall(efi_memreserve_root_init); > > #ifdef CONFIG_KEXEC > static int update_efi_random_seed(struct notifier_block *nb, >
The following changes since commit ccda4af0f4b92f7b4c308d3acc262f4a7e3affad: Linux 4.20-rc2 (2018-11-11 17:12:31 -0600) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git efi-urgent for you to fetch changes up to 844d2592ed2f1903f8e38d8d395fd0d38ecdd536: efi: permit calling efi_mem_reserve_persistent from atomic context (2018-11-14 05:49:28 -0800) ---------------------------------------------------------------- EFI fixes for v4.20: - fix incorrect 'on stack' annotation of efi_rts_work (all EFI arches) - revert deferred memory map unmapping on ARM - pack the FDT before handing over to the OS (ARM, arm64) - fixes for new persistent memreserve feature (ARM, arm64) ---------------------------------------------------------------- Ard Biesheuvel (4): efi: arm: revert deferred unmap of early memmap mapping efi/arm: libstub: pack FDT after populating it efi/arm: defer persistent reservations until after paging_init() efi: permit calling efi_mem_reserve_persistent from atomic context Waiman Long (1): efi: Fix debugobjects warning on efi_rts_work arch/arm64/kernel/setup.c | 1 + drivers/firmware/efi/arm-init.c | 4 ++++ drivers/firmware/efi/arm-runtime.c | 2 +- drivers/firmware/efi/efi.c | 35 ++++++++++++++++++++++----------- drivers/firmware/efi/libstub/arm-stub.c | 3 +++ drivers/firmware/efi/libstub/fdt.c | 4 ++++ drivers/firmware/efi/memmap.c | 3 +++ drivers/firmware/efi/runtime-wrappers.c | 2 +- include/linux/efi.h | 7 +++++++ 9 files changed, 47 insertions(+), 14 deletions(-)