Fix the linker scripts to generate three distinct PT_LOAD segments with correct permissions instead of combining .rodata with .data.
Before this fix, the linker auto-generated only two PT_LOAD segments: 1. Text segment (PF_R|PF_X) 2. Data segment (PF_R|PF_W) - containing .rodata, .data, .bss, etc. This caused .rodata to be mapped with write permissions when pbl_mmu_setup_from_elf() set up MMU permissions based on ELF segments, defeating the W^X protection that commit d9ccb0cf14 intended to provide. With explicit PHDRS directives, we now generate three segments: 1. text segment (PF_R|PF_X): .text and related code sections 2. rodata segment (PF_R): .rodata and unwind tables 3. data segment (PF_R|PF_W): .data, .bss, and related sections This ensures pbl_mmu_setup_from_elf() correctly maps .rodata as read-only (MAP_CACHED_RO) instead of read-write (MAP_CACHED). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Sonnet 4.5 <[email protected]> Signed-off-by: Sascha Hauer <[email protected]> --- arch/arm/lib32/barebox.lds.S | 34 ++++++++++++++++++++++------------ arch/arm/lib64/barebox.lds.S | 29 +++++++++++++++++++---------- 2 files changed, 41 insertions(+), 22 deletions(-) diff --git a/arch/arm/lib32/barebox.lds.S b/arch/arm/lib32/barebox.lds.S index c704dd6d70f3ab157ceb67dfb14760e03f2a5d62..2fb43b4619ff29d8d21dd579d3a3002b7134ff71 100644 --- a/arch/arm/lib32/barebox.lds.S +++ b/arch/arm/lib32/barebox.lds.S @@ -7,14 +7,23 @@ OUTPUT_FORMAT(BAREBOX_OUTPUT_FORMAT) OUTPUT_ARCH(BAREBOX_OUTPUT_ARCH) ENTRY(start) + +PHDRS +{ + text PT_LOAD FLAGS(5); /* PF_R | PF_X */ + rodata PT_LOAD FLAGS(4); /* PF_R */ + data PT_LOAD FLAGS(6); /* PF_R | PF_W */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ +} + SECTIONS { . = 0x0; - .image_start : { *(.__image_start) } + .image_start : { *(.__image_start) } :text . = ALIGN(4); - ._text : { *(._text) } + ._text : { *(._text) } :text .text : { _stext = .; @@ -27,7 +36,7 @@ SECTIONS KEEP(*(.text_exceptions*)) __exceptions_stop = .; *(.text*) - } + } :text BAREBOX_BARE_INIT_SIZE . = ALIGN(4096); @@ -35,7 +44,7 @@ SECTIONS .rodata : { *(.rodata*) RO_DATA_SECTION - } + } :rodata #ifdef CONFIG_ARM_UNWIND /* @@ -46,20 +55,21 @@ SECTIONS __start_unwind_idx = .; *(.ARM.exidx*) __stop_unwind_idx = .; - } + } :rodata .ARM.unwind_tab : { __start_unwind_tab = .; *(.ARM.extab*) __stop_unwind_tab = .; - } + } :rodata #endif . = ALIGN(4096); __end_rodata = .; _etext = .; _sdata = .; - . = ALIGN(4); - .data : { *(.data*) } + .data : { *(.data*) } :data + + .dynamic : { *(.dynamic) } :data :dynamic . = .; @@ -69,12 +79,12 @@ SECTIONS BAREBOX_EFI_RUNTIME - .image_end : { *(.__image_end) } + .image_end : { *(.__image_end) } :data . = ALIGN(4); - .__bss_start : { *(.__bss_start) } - .bss : { *(.bss*) } - .__bss_stop : { *(.__bss_stop) } + .__bss_start : { *(.__bss_start) } :data + .bss : { *(.bss*) } :data + .__bss_stop : { *(.__bss_stop) } :data #ifdef CONFIG_ARM_SECURE_MONITOR . = ALIGN(16); diff --git a/arch/arm/lib64/barebox.lds.S b/arch/arm/lib64/barebox.lds.S index 5ee5fbc3741e1f7644c00f9b37c0903c27704a3e..71f677a917851270e09c6d439fe5cbe4b6b41034 100644 --- a/arch/arm/lib64/barebox.lds.S +++ b/arch/arm/lib64/barebox.lds.S @@ -6,14 +6,23 @@ OUTPUT_FORMAT(BAREBOX_OUTPUT_FORMAT) OUTPUT_ARCH(BAREBOX_OUTPUT_ARCH) ENTRY(start) + +PHDRS +{ + text PT_LOAD FLAGS(5); /* PF_R | PF_X */ + rodata PT_LOAD FLAGS(4); /* PF_R */ + data PT_LOAD FLAGS(6); /* PF_R | PF_W */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ +} + SECTIONS { . = 0x0; - .image_start : { *(.__image_start) } + .image_start : { *(.__image_start) } :text . = ALIGN(4); - ._text : { *(._text) } + ._text : { *(._text) } :text .text : { _stext = .; @@ -22,7 +31,7 @@ SECTIONS *(.text_bare_init*) __bare_init_end = .; *(.text*) - } + } :text BAREBOX_BARE_INIT_SIZE . = ALIGN(4096); @@ -30,7 +39,7 @@ SECTIONS .rodata : { *(.rodata*) RO_DATA_SECTION - } + } :rodata . = ALIGN(4096); @@ -38,20 +47,20 @@ SECTIONS _etext = .; _sdata = .; - .data : { *(.data*) } + .data : { *(.data*) } :data - BAREBOX_RELOCATION_TABLE + .dynamic : { *(.dynamic) } :data :dynamic _edata = .; BAREBOX_EFI_RUNTIME - .image_end : { *(.__image_end) } + .image_end : { *(.__image_end) } :data . = ALIGN(4); - .__bss_start : { *(.__bss_start) } - .bss : { *(.bss*) } - .__bss_stop : { *(.__bss_stop) } + .__bss_start : { *(.__bss_start) } :data + .bss : { *(.bss*) } :data + .__bss_stop : { *(.__bss_stop) } :data _end = .; _barebox_image_size = __bss_start; } -- 2.47.3
