On 1/8/26 4:50 PM, Sascha Hauer wrote: > 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.
Remove references to commits within this series. > > 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 */ Move one up for readability (segments with same permissions listed next to each other). > +} > + > 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 Replace :data with :rodata and move it up just before __end_rodata, so it's actually read-only. > --- 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 */ Same feedback as for arm32. > - BAREBOX_RELOCATION_TABLE > + .dynamic : { *(.dynamic) } :data :dynamic Ditto. Cheers, Ahmad -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
