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2021-01-20efi_loader: Avoid emitting efi_var_buf to .GOTIlias Apalodimas
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>
2020-11-21efi_loader: parameter check in GetNextVariableName()Heinrich Schuchardt
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>
2020-09-14efi_loader: efi_var_mem_notify_exit_boot_servicesHeinrich Schuchardt
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: f1f990a8c958 ("efi_loader: memory buffer for variables") Fixes: e01aed47d6a0 ("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>
2020-08-01efi_loader: Enable run-time variable support for tee based variablesIlias Apalodimas
We recently added functions for storing/restoring variables from a file to a memory backed buffer marked as __efi_runtime_data commit f1f990a8c958 ("efi_loader: memory buffer for variables") commit 5f7dcf079de8 ("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>
2020-07-22efi_loader: don't use memmove() in efi_var_mem_del()Heinrich Schuchardt
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>
2020-07-22efi_loader: efi_current_var after SetVirtualAddressMapHeinrich Schuchardt
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: b02a707152dc ("efi_loader: enable UEFI variables at runtime") Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2020-07-11efi_loader: memory buffer for variablesHeinrich Schuchardt
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>