| Message ID | 1410195668-9975-1-git-send-email-msalter@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
On Mon, 08 Sep, at 01:01:08PM, Mark Salter wrote: > Commit 86c8b27a01cf: > "arm64: ignore DT memreserve entries when booting in UEFI mode > > prevents early_init_fdt_scan_reserved_mem() from being called for > arm64 kernels booting via UEFI. This was done because the kernel > will use the UEFI memory map to determine reserved memory regions. > That approach has problems in that early_init_fdt_scan_reserved_mem() > also reserves the FDT itself and any node-specific reserved memory. > By chance of some kernel configs, the FDT may be overwritten before > it can be unflattened and the kernel will fail to boot. More subtle > problems will result if the FDT has node specific reserved memory > which is not really reserved. > > This patch has the UEFI stub remove the memory reserve map entries > from the FDT as it does with the memory nodes. This allows > early_init_fdt_scan_reserved_mem() to be called unconditionally > so that the other needed reservations are made. > > Change from v1: > * Acks added > * Fixed loop logic to remove reserved regions > > Signed-off-by: Mark Salter <msalter@redhat.com> > Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Acked-by: Mark Rutland <mark.rutland@arm.com> > --- > arch/arm64/mm/init.c | 3 +-- > drivers/firmware/efi/libstub/fdt.c | 10 +++++++++- > 2 files changed, 10 insertions(+), 3 deletions(-) Thanks Mark, queued up in 'urgent'.
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 5472c24..a83061f 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -149,8 +149,7 @@ void __init arm64_memblock_init(void) memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start); #endif - if (!efi_enabled(EFI_MEMMAP)) - early_init_fdt_scan_reserved_mem(); + early_init_fdt_scan_reserved_mem(); /* 4GB maximum for 32-bit only capable devices */ if (IS_ENABLED(CONFIG_ZONE_DMA)) diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index a56bb35..c846a96 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -22,7 +22,7 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, unsigned long map_size, unsigned long desc_size, u32 desc_ver) { - int node, prev; + int node, prev, num_rsv; int status; u32 fdt_val32; u64 fdt_val64; @@ -73,6 +73,14 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, prev = node; } + /* + * Delete all memory reserve map entries. When booting via UEFI, + * kernel will use the UEFI memory map to find reserved regions. + */ + num_rsv = fdt_num_mem_rsv(fdt); + while (num_rsv-- > 0) + fdt_del_mem_rsv(fdt, num_rsv); + node = fdt_subnode_offset(fdt, 0, "chosen"); if (node < 0) { node = fdt_add_subnode(fdt, 0, "chosen");