diff options
| author | Ilias Apalodimas <ilias.apalodimas@linaro.org> | 2021-01-16 17:28:04 +0200 |
|---|---|---|
| committer | Heinrich Schuchardt <xypron.glpk@gmx.de> | 2021-01-20 08:17:17 +0100 |
| commit | 53e54bf50d285597c1553cdf2bd0e646fcd4dd60 (patch) | |
| tree | 2aefe4af42c90de0635de5324af86ed1b912095e /lib | |
| parent | 0a7e5165ec21d8092565a833211b21b356195398 (diff) | |
| download | u-boot-53e54bf50d285597c1553cdf2bd0e646fcd4dd60.tar.gz | |
efi_loader: Avoid emitting efi_var_buf to .GOT
Atish reports that on RISC-V, accessing the EFI variables causes
a kernel panic. An objdump of the file verifies that, since the
global pointer for efi_var_buf ends up in .GOT section which is
not mapped in virtual address space for Linux.
<snip of efi_var_mem_find>
0000000000000084 <efi_var_mem_find>:
84: 715d addi sp,sp,-80
* objdump -dr
0000000000000086 <.LCFI2>:
86: e0a2 sd s0,64(sp)
88: fc26 sd s1,56(sp)
8a: e486 sd ra,72(sp)
8c: f84a sd s2,48(sp)
8e: f44e sd s3,40(sp)
90: f052 sd s4,32(sp)
92: ec56 sd s5,24(sp)
94: 00000497 auipc s1,0x0
94: R_RISCV_GOT_HI20 efi_var_buf
98: 0004b483 ld s1,0(s1) # 94 <.LCFI2+0xe>
98: R_RISCV_PCREL_LO12_I .L0
98: R_RISCV_RELAX *ABS*
* objdump -t
0000000000000084 g F .text.efi_runtime 00000000000000b8 efi_var_mem_find
With the patch applied:
* objdump -dr
0000000000000086 <.LCFI2>:
86: e0a2 sd s0,64(sp)
88: fc26 sd s1,56(sp)
8a: e486 sd ra,72(sp)
8c: f84a sd s2,48(sp)
8e: f44e sd s3,40(sp)
90: f052 sd s4,32(sp)
92: ec56 sd s5,24(sp)
94: 00000497 auipc s1,0x0
94: R_RISCV_PCREL_HI20 .LANCHOR0
94: R_RISCV_RELAX *ABS*
98: 00048493 mv s1,s1
98: R_RISCV_PCREL_LO12_I .L0
98: R_RISCV_RELAX *ABS*
* objdump -t
0000000000000008 l O .data.efi_runtime 0000000000000008 efi_var_buf
On arm64 this works, because there's no .GOT entries for this
and everything is converted to relative references.
* objdump -dr (identical pre-post patch, only the new function shows up)
00000000000000b4 <efi_var_mem_find>:
b4: aa0003ee mov x14, x0
b8: 9000000a adrp x10, 0 <efi_var_mem_compare>
b8: R_AARCH64_ADR_PREL_PG_HI21 .data.efi_runtime
bc: 91000140 add x0, x10, #0x0
bc: R_AARCH64_ADD_ABS_LO12_NC .data.efi_runtime
c0: aa0103ed mov x13, x1
c4: 79400021 ldrh w1, [x1]
c8: aa0203eb mov x11, x2
cc: f9400400 ldr x0, [x0, #8]
d0: b940100c ldr w12, [x0, #16]
d4: 8b0c000c add x12, x0, x12
So let's switch efi_var_buf to static and create a helper function for
anyone that needs to update it.
Fixes: e01aed47d6a0 ("efi_loader: Enable run-time variable support for tee based variables")
Reported-by: Atish Patra <atishp@atishpatra.org>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/efi_loader/efi_var_mem.c | 13 | ||||
| -rw-r--r-- | lib/efi_loader/efi_variable_tee.c | 2 |
2 files changed, 13 insertions, 2 deletions
diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c index d155f25f60..3d335a8274 100644 --- a/lib/efi_loader/efi_var_mem.c +++ b/lib/efi_loader/efi_var_mem.c @@ -10,7 +10,13 @@ #include <efi_variable.h> #include <u-boot/crc.h> -struct efi_var_file __efi_runtime_data *efi_var_buf; +/* + * The variables efi_var_file and efi_var_entry must be static to avoid + * referencing them via the global offset table (section .got). The GOT + * is neither mapped as EfiRuntimeServicesData nor do we support its + * relocation during SetVirtualAddressMap(). + */ +static struct efi_var_file __efi_runtime_data *efi_var_buf; static struct efi_var_entry __efi_runtime_data *efi_current_var; /** @@ -339,3 +345,8 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, return EFI_SUCCESS; } + +void efi_var_buf_update(struct efi_var_file *var_buf) +{ + memcpy(efi_var_buf, var_buf, EFI_VAR_BUF_SIZE); +} diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c index b8808fdeca..51920bcb51 100644 --- a/lib/efi_loader/efi_variable_tee.c +++ b/lib/efi_loader/efi_variable_tee.c @@ -702,7 +702,7 @@ void efi_variables_boot_exit_notify(void) if (ret != EFI_SUCCESS) log_err("Can't populate EFI variables. No runtime variables will be available\n"); else - memcpy(efi_var_buf, var_buf, len); + efi_var_buf_update(var_buf); free(var_buf); /* Update runtime service table */ |