[PATCH v2 4/5] ARM: vmlinux-xip.lds.S: fix multiple issues
From: Ard Biesheuvel <hidden>
Date: 2017-08-30 15:12:45
On 30 August 2017 at 03:55, Nicolas Pitre [off-list ref] wrote:
The XIP linker script has several problems: - PAGE_ALIGNED_DATA is missing and is likely to end up somewhere with the wrong LMA. - BUG_TABLE definitely has the wrong LMA, it is not copied to RAM, and its VMA is unaccounted for and likely to clash with dynamic memory usage. - TCM usage is similarly broken. - PERCPU_SECTION is left in ROM despite being written to. Let's use generic macros for those things and locate them appropriately. Incidentally, those macros are usable with a LMA != VMA already by properly defining LOAD_OFFSET. TCM is not fixed here. It never worked in a XIP configuration anyway, so that can wait until another round of cleanups. Signed-off-by: Nicolas Pitre <redacted>
Acked-by: Ard Biesheuvel <redacted>
quoted hunk ↗ jump to hunk
--- arch/arm/kernel/vmlinux-xip.lds.S | 70 +++++++++++++++++++-------------------- 1 file changed, 34 insertions(+), 36 deletions(-)diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S index 88e8db3979..39b1fb470a 100644 --- a/arch/arm/kernel/vmlinux-xip.lds.S +++ b/arch/arm/kernel/vmlinux-xip.lds.S@@ -179,7 +179,7 @@ SECTIONS *(.taglist.init) __tagtable_end = .; } - .init.data : { + .init.rodata : { INIT_SETUP(16) INIT_CALLS CON_INITCALL@@ -187,48 +187,46 @@ SECTIONS INIT_RAM_FS } -#ifdef CONFIG_SMP - PERCPU_SECTION(L1_CACHE_BYTES) -#endif - _exiprom = .; /* End of XIP ROM area */ - __data_loc = ALIGN(4); /* location in binary */ - . = PAGE_OFFSET + TEXT_OFFSET; - - .data : AT(__data_loc) { - _data = .; /* address in memory */ - _sdata = .; - /* - * first, the init task union, aligned - * to an 8192 byte boundary. - */ - INIT_TASK_DATA(THREAD_SIZE) +/* + * From this point, stuff is considered writable and will be copied to RAM + */ + __data_loc = ALIGN(4); /* location in file */ + . = PAGE_OFFSET + TEXT_OFFSET; /* location in memory */ +#undef LOAD_OFFSET +#define LOAD_OFFSET (PAGE_OFFSET + TEXT_OFFSET - __data_loc) + + . = ALIGN(THREAD_SIZE); + _sdata = .; + RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE) + .data.ro_after_init : AT(ADDR(.data.ro_after_init) - LOAD_OFFSET) { + *(.data..ro_after_init) + } + _edata = .; - . = ALIGN(PAGE_SIZE); - __init_begin = .; + . = ALIGN(PAGE_SIZE); + __init_begin = .; + .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { INIT_DATA + } + .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) { ARM_EXIT_KEEP(EXIT_DATA) - . = ALIGN(PAGE_SIZE); - __init_end = .; - - *(.data..ro_after_init) - - NOSAVE_DATA - CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES) - READ_MOSTLY_DATA(L1_CACHE_BYTES) - - /* - * and the usual data section - */ - DATA_DATA - CONSTRUCTORS - - _edata = .; } - _edata_loc = __data_loc + SIZEOF(.data); +#ifdef CONFIG_SMP + PERCPU_SECTION(L1_CACHE_BYTES) +#endif + + /* + * End of copied data. We need a dummy section to get its LMA. + * Also located before final ALIGN() as trailing padding is not stored + * in the resulting binary file and useless to copy. + */ + .data.endmark : AT(ADDR(.data.endmark) - LOAD_OFFSET) { } + _edata_loc = LOADADDR(.data.endmark); - BUG_TABLE + . = ALIGN(PAGE_SIZE); + __init_end = .; #ifdef CONFIG_HAVE_TCM /* --2.9.5