diff options
| -rw-r--r-- | bl31/aarch64/bl31_entrypoint.S | 13 | ||||
| -rw-r--r-- | bl31/bl31.ld.S | 28 | ||||
| -rw-r--r-- | include/common/bl_common.h | 1 | ||||
| -rw-r--r-- | lib/aarch64/misc_helpers.S | 116 | ||||
| -rw-r--r-- | lib/pmf/pmf_main.c | 5 |
5 files changed, 154 insertions, 9 deletions
diff --git a/bl31/aarch64/bl31_entrypoint.S b/bl31/aarch64/bl31_entrypoint.S index 3a45e53f..7c116a2e 100644 --- a/bl31/aarch64/bl31_entrypoint.S +++ b/bl31/aarch64/bl31_entrypoint.S @@ -7,6 +7,7 @@ #include <arch.h> #include <bl_common.h> #include <el3_common_macros.S> +#include <platform_def.h> #include <pmf_asm_macros.S> #include <runtime_instr.h> #include <xlat_mmu_helpers.h> @@ -73,6 +74,18 @@ func bl31_entrypoint mov x22, 0 mov x23, 0 #endif /* RESET_TO_BL31 */ + + /* -------------------------------------------------------------------- + * If PIE is enabled, fixup the Global descriptor Table and dynamic + * relocations + * -------------------------------------------------------------------- + */ +#if ENABLE_PIE + mov_imm x0, BL31_BASE + mov_imm x1, BL31_LIMIT + bl fixup_gdt_reloc +#endif /* ENABLE_PIE */ + /* --------------------------------------------- * Perform platform specific early arch. setup * --------------------------------------------- diff --git a/bl31/bl31.ld.S b/bl31/bl31.ld.S index 81e7ba3a..43d0ed44 100644 --- a/bl31/bl31.ld.S +++ b/bl31/bl31.ld.S @@ -26,6 +26,8 @@ SECTIONS ASSERT(. == ALIGN(PAGE_SIZE), "BL31_BASE address is not aligned on a page boundary.") + __BL31_START__ = .; + #if SEPARATE_CODE_AND_RODATA .text . : { __TEXT_START__ = .; @@ -63,6 +65,16 @@ SECTIONS KEEP(*(cpu_ops)) __CPU_OPS_END__ = .; + /* + * Keep the .got section in the RO section as the it is patched + * prior to enabling the MMU and having the .got in RO is better for + * security. + */ + . = ALIGN(16); + __GOT_START__ = .; + *(.got) + __GOT_END__ = .; + /* Place pubsub sections for events */ . = ALIGN(8); #include <pubsub_events.h> @@ -153,6 +165,16 @@ SECTIONS __DATA_END__ = .; } >RAM + . = ALIGN(16); + /* + * .rela.dyn needs to come after .data for the read-elf utility to parse + * this section correctly. + */ + __RELA_START__ = .; + .rela.dyn . : { + } >RAM + __RELA_END__ = .; + #ifdef BL31_PROGBITS_LIMIT ASSERT(. <= BL31_PROGBITS_LIMIT, "BL31 progbits has exceeded its limit.") #endif @@ -265,11 +287,5 @@ SECTIONS __RW_END__ = .; __BL31_END__ = .; - __BSS_SIZE__ = SIZEOF(.bss); -#if USE_COHERENT_MEM - __COHERENT_RAM_UNALIGNED_SIZE__ = - __COHERENT_RAM_END_UNALIGNED__ - __COHERENT_RAM_START__; -#endif - ASSERT(. <= BL31_LIMIT, "BL31 image has exceeded its limit.") } diff --git a/include/common/bl_common.h b/include/common/bl_common.h index 2ecf281c..6a79dc33 100644 --- a/include/common/bl_common.h +++ b/include/common/bl_common.h @@ -83,6 +83,7 @@ IMPORT_SYM(unsigned long, __BL2_END__, BL2_END); #elif defined(IMAGE_BL2U) IMPORT_SYM(unsigned long, __BL2U_END__, BL2U_END); #elif defined(IMAGE_BL31) +IMPORT_SYM(unsigned long, __BL31_START__, BL31_START); IMPORT_SYM(unsigned long, __BL31_END__, BL31_END); #elif defined(IMAGE_BL32) IMPORT_SYM(unsigned long, __BL32_END__, BL32_END); diff --git a/lib/aarch64/misc_helpers.S b/lib/aarch64/misc_helpers.S index 1a075aa5..002942e8 100644 --- a/lib/aarch64/misc_helpers.S +++ b/lib/aarch64/misc_helpers.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -7,6 +7,7 @@ #include <arch.h> #include <asm_macros.S> #include <assert_macros.S> +#include <xlat_tables_defs.h> .globl get_afflvl_shift .globl mpidr_mask_lower_afflvls @@ -23,6 +24,8 @@ .globl disable_mmu_icache_el1 .globl disable_mmu_icache_el3 + .globl fixup_gdt_reloc + #if SUPPORT_VFP .globl enable_vfp #endif @@ -497,3 +500,114 @@ func enable_vfp ret endfunc enable_vfp #endif + +/* --------------------------------------------------------------------------- + * Helper to fixup Global Descriptor table (GDT) and dynamic relocations + * (.rela.dyn) at runtime. + * + * This function is meant to be used when the firmware is compiled with -fpie + * and linked with -pie options. We rely on the linker script exporting + * appropriate markers for start and end of the section. For GOT, we + * expect __GOT_START__ and __GOT_END__. Similarly for .rela.dyn, we expect + * __RELA_START__ and __RELA_END__. + * + * The function takes the limits of the memory to apply fixups to as + * arguments (which is usually the limits of the relocable BL image). + * x0 - the start of the fixup region + * x1 - the limit of the fixup region + * These addresses have to be page (4KB aligned). + * --------------------------------------------------------------------------- + */ +func fixup_gdt_reloc + mov x6, x0 + mov x7, x1 + + /* Test if the limits are 4K aligned */ +#if ENABLE_ASSERTIONS + orr x0, x0, x1 + tst x0, #(PAGE_SIZE - 1) + ASM_ASSERT(eq) +#endif + /* + * Calculate the offset based on return address in x30. + * Assume that this funtion is called within a page of the start of + * of fixup region. + */ + and x2, x30, #~(PAGE_SIZE - 1) + sub x0, x2, x6 /* Diff(S) = Current Address - Compiled Address */ + + adrp x1, __GOT_START__ + add x1, x1, :lo12:__GOT_START__ + adrp x2, __GOT_END__ + add x2, x2, :lo12:__GOT_END__ + + /* + * GOT is an array of 64_bit addresses which must be fixed up as + * new_addr = old_addr + Diff(S). + * The new_addr is the address currently the binary is executing from + * and old_addr is the address at compile time. + */ +1: + ldr x3, [x1] + /* Skip adding offset if address is < lower limit */ + cmp x3, x6 + b.lo 2f + /* Skip adding offset if address is >= upper limit */ + cmp x3, x7 + b.ge 2f + add x3, x3, x0 + str x3, [x1] +2: + add x1, x1, #8 + cmp x1, x2 + b.lo 1b + + /* Starting dynamic relocations. Use adrp/adr to get RELA_START and END */ + adrp x1, __RELA_START__ + add x1, x1, :lo12:__RELA_START__ + adrp x2, __RELA_END__ + add x2, x2, :lo12:__RELA_END__ + /* + * According to ELF-64 specification, the RELA data structure is as + * follows: + * typedef struct + * { + * Elf64_Addr r_offset; + * Elf64_Xword r_info; + * Elf64_Sxword r_addend; + * } Elf64_Rela; + * + * r_offset is address of reference + * r_info is symbol index and type of relocation (in this case + * 0x403 which corresponds to R_AARCH64_RELATIV). + * r_addend is constant part of expression. + * + * Size of Elf64_Rela structure is 24 bytes. + */ +1: + /* Assert that the relocation type is R_AARCH64_RELATIV */ +#if ENABLE_ASSERTIONS + ldr x3, [x1, #8] + cmp x3, #0x403 + ASM_ASSERT(eq) +#endif + ldr x3, [x1] /* r_offset */ + add x3, x0, x3 + ldr x4, [x1, #16] /* r_addend */ + + /* Skip adding offset if r_addend is < lower limit */ + cmp x4, x6 + b.lo 2f + /* Skip adding offset if r_addend entry is >= upper limit */ + cmp x4, x7 + b.ge 2f + + add x4, x0, x4 /* Diff(S) + r_addend */ + str x4, [x3] + +2: add x1, x1, #24 + cmp x1, x2 + b.lo 1b + + ret +endfunc fixup_gdt_reloc diff --git a/lib/pmf/pmf_main.c b/lib/pmf/pmf_main.c index a0208600..25513c19 100644 --- a/lib/pmf/pmf_main.c +++ b/lib/pmf/pmf_main.c @@ -25,9 +25,10 @@ IMPORT_SYM(uintptr_t, __PMF_SVC_DESCS_START__, PMF_SVC_DESCS_START); IMPORT_SYM(uintptr_t, __PMF_SVC_DESCS_END__, PMF_SVC_DESCS_END); -IMPORT_SYM(uintptr_t, __PERCPU_TIMESTAMP_SIZE__, PMF_PERCPU_TIMESTAMP_SIZE); +IMPORT_SYM(uintptr_t, __PMF_PERCPU_TIMESTAMP_END__, PMF_PERCPU_TIMESTAMP_END); IMPORT_SYM(intptr_t, __PMF_TIMESTAMP_START__, PMF_TIMESTAMP_ARRAY_START); -IMPORT_SYM(uintptr_t, __PMF_TIMESTAMP_END__, PMF_TIMESTAMP_ARRAY_END); + +#define PMF_PERCPU_TIMESTAMP_SIZE (PMF_PERCPU_TIMESTAMP_END - PMF_TIMESTAMP_ARRAY_START) #define PMF_SVC_DESCS_MAX 10 |