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cmd: bootefi: allocate device-tree copy from high memory

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The bootefi command creates a copy of the device-tree within the first
127 MiB of memory. This may lead to overwriting previously loaded binaries
(e.g. kernel, initrd).

Linux EFI stub itself copies U-Boot's copy of the device-tree. This means
there is not restriction for U-Boot to place the device-tree copy to any
address. (Restrictions existed for 32bit ARM before Linux commit
7a1be318f579 ("ARM: 9012/1: move device tree mapping out of linear region")
for legacy booting.

Reported-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
This commit is contained in:
Heinrich Schuchardt 2023-02-23 20:27:38 +01:00
parent ed10008bab
commit 93e3364804
1 changed files with 3 additions and 16 deletions
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19
cmd/bootefi.c
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@ -204,25 +204,12 @@ static efi_status_t copy_fdt(void **fdtp)
fdt_pages = efi_size_in_pages(fdt_totalsize(fdt) + 0x3000);
fdt_size = fdt_pages << EFI_PAGE_SHIFT;
/*
* Safe fdt location is at 127 MiB.
* On the sandbox convert from the sandbox address space.
*/
new_fdt_addr = (uintptr_t)map_sysmem(fdt_ram_start + 0x7f00000 +
fdt_size, 0);
ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
&new_fdt_addr);
if (ret != EFI_SUCCESS) {
/* If we can't put it there, put it somewhere */
new_fdt_addr = (ulong)memalign(EFI_PAGE_SIZE, fdt_size);
ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
&new_fdt_addr);
if (ret != EFI_SUCCESS) {
log_err("ERROR: Failed to reserve space for FDT\n");
goto done;
}
log_err("ERROR: Failed to reserve space for FDT\n");
goto done;
}
new_fdt = (void *)(uintptr_t)new_fdt_addr;
memcpy(new_fdt, fdt, fdt_totalsize(fdt));