Unverified Commit b635a84b authored by Nam Cao's avatar Nam Cao Committed by Palmer Dabbelt
Browse files

riscv: remove limit on the size of read-only section for XIP kernel 



XIP_OFFSET is the hard-coded offset of writable data section within the
kernel.

By hard-coding this value, the read-only section of the kernel (which is
placed before the writable data section) is restricted in size. This causes
build failures if the kernel gets too big [1].

Remove this limit.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404211031.J6l2AfJk-lkp@intel.com

 [1]
Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
Reviewed-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/3bf3a77be10ebb0d8086c028500baa16e7a8e648.1717789719.git.namcao@linutronix.de


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent a7cfb999

arch/riscv/include/asm/pgtable.h

+0 −7
Original line number Diff line number Diff line
@@ -107,13 +107,6 @@ 


#endif



#ifdef CONFIG_XIP_KERNEL

#define XIP_OFFSET		SZ_32M

#define XIP_OFFSET_MASK		(SZ_32M - 1)

#else

#define XIP_OFFSET		0

#endif



#ifndef __ASSEMBLY__



#include <asm/page.h>

arch/riscv/include/asm/set_memory.h

+1 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ bool kernel_page_present(struct page *page); 


#endif /* __ASSEMBLY__ */



#ifdef CONFIG_STRICT_KERNEL_RWX

#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_XIP_KERNEL)

#ifdef CONFIG_64BIT

#define SECTION_ALIGN (1 << 21)

#else

arch/riscv/kernel/vmlinux-xip.lds.S

+3 −2
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <asm/page.h>

#include <asm/cache.h>

#include <asm/thread_info.h>

#include <asm/set_memory.h>



OUTPUT_ARCH(riscv)

ENTRY(_start)
@@ -65,10 +66,10 @@ SECTIONS 
 * From this point, stuff is considered writable and will be copied to RAM

 */

	__data_loc = ALIGN(PAGE_SIZE);		/* location in file */

	. = KERNEL_LINK_ADDR + XIP_OFFSET;	/* location in memory */

	. = ALIGN(SECTION_ALIGN);		/* location in memory */



#undef LOAD_OFFSET

#define LOAD_OFFSET (KERNEL_LINK_ADDR + XIP_OFFSET - (__data_loc & XIP_OFFSET_MASK))

#define LOAD_OFFSET (KERNEL_LINK_ADDR + _sdata - __data_loc)



	_sdata = .;			/* Start of data section */

	_data = .;