Commit graph

10 commits

Author SHA1 Message Date
Heinrich Schuchardt
f557cf08b9 efi_loader: use u16_strlen() in efi_var_mem_ins()
Don't duplicate library functionality.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2022-12-29 12:52:39 +01:00
Heinrich Schuchardt
70a4ac693d efi_loader: fix efi_get_next_variable_name_mem()
The VariableNameSize parameter is in bytes but u16_strnlen() counts u16.

Fix the parameter check for null termination.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2022-12-20 16:06:48 +01:00
Heinrich Schuchardt
d47671c631 efi_loader: treat UEFI variable name as const
UEFI variable names are typically constants and hence should be defined as
const. Unfortunately some of our API functions do not define the parameters
for UEFI variable names as const. This requires unnecessary conversions.

Adjust parameters of several internal functions to tre UEFI variable names
as const.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-10-25 21:13:06 +02:00
Ilias Apalodimas
53e54bf50d 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: e01aed47d6 ("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>
2021-01-20 08:17:17 +01:00
Heinrich Schuchardt
7e5875a856 efi_loader: parameter check in GetNextVariableName()
If GetNextVariableName() is called with a non-existing combination of
VariableName and VendorGuid, return EFI_INVALID_PARAMETER.

If GetNextVariableName() is called with a string that is not zero
terminated, return EFI_INVALID_PARAMETER.

Reformat a line over 80 characters.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-11-21 07:26:16 +01:00
Heinrich Schuchardt
e5a31376ac efi_loader: efi_var_mem_notify_exit_boot_services
efi_var_mem_notify_exit_boot_services() is invoked when ExitBootServices()
is called by the UEFI payload.

efi_var_mem_notify_exit_boot_services() should not be defined as
__efi_runtime as it is invoking EFI_ENTRY() and EFI_EXIT() which themselves
are not __efi_runtime.

Fixes: f1f990a8c9 ("efi_loader: memory buffer for variables")
Fixes: e01aed47d6 ("efi_loader: Enable run-time variable support for tee based variables")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2020-09-14 23:28:52 +02:00
Ilias Apalodimas
e01aed47d6 efi_loader: Enable run-time variable support for tee based variables
We recently added functions for storing/restoring variables
from a file to a memory backed buffer marked as __efi_runtime_data
commit f1f990a8c9 ("efi_loader: memory buffer for variables")
commit 5f7dcf079d ("efi_loader: UEFI variable persistence")

Using the same idea we now can support GetVariable() and GetNextVariable()
on the OP-TEE based variables as well.

So let's re-arrange the code a bit and move the commmon code for
accessing variables out of efi_variable.c. Create common functions for
reading variables from memory that both implementations can use on
run-time. Then just use those functions in the run-time variants of the
OP-TEE based EFI variable implementation and initialize the memory
buffer on ExitBootServices()

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-08-01 11:57:41 +02:00
Heinrich Schuchardt
ebbad02c1b efi_loader: don't use memmove() in efi_var_mem_del()
efi_var_mem_del() is in __efi_runtime because it would be needed for a
runtime implementation of SetVariable(). memmove() is not in __efi_runtime.
So we should not use it in efi_var_mem_del().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-22 12:32:41 +02:00
Heinrich Schuchardt
01fa922bbb efi_loader: efi_current_var after SetVirtualAddressMap
Variable efi_current_var is a pointer to a physical memory address that
becomes invalid after SetVirtualAddressMap(). Instead of converting it via
ConvertPointer() simply set it to NULL.

Fixes: b02a707152 ("efi_loader: enable UEFI variables at runtime")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-22 12:32:41 +02:00
Heinrich Schuchardt
f1f990a8c9 efi_loader: memory buffer for variables
Saving UEFI variable as encoded U-Boot environment variables does not allow
support at runtime.

Provide functions to manage a memory buffer with UEFI variables.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11 23:14:17 +02:00