| Message ID | 1447362108-4333-1-git-send-email-chris.brandt@renesas.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Chris, On Thu, Nov 12, 2015 at 10:01 PM, Chris Brandt <chris.brandt@renesas.com> wrote: > For an XIP build, _edata_loc, not _etext, represents the end of the > binary image that will be programmed into ROM and mapped into the > MODULES_VADDR area. > With an XIP kernel, nothing is loaded into RAM before boot, meaning > you have to take into account the size of the entire binary image > that was programmed, including the init data values that will be copied > to RAM during kernel boot. > > This fixes the bug where you might lose the end of your kernel area > after page table setup is complete. Thanks for your patch! > Signed-off-by: Chris Brandt <chris.brandt@renesas.com> > --- > v2 > * Added change for MODULES_VADDR > * Moved extern to new file asm/sections.h > --- > arch/arm/include/asm/sections.h | 8 ++++++++ > arch/arm/kernel/module.c | 2 +- > arch/arm/mm/mmu.c | 4 ++-- > 3 files changed, 11 insertions(+), 3 deletions(-) > create mode 100644 arch/arm/include/asm/sections.h If you create an arm-specific <asm/sections.h>, you also have to remove the line generic-y += sections.h from arch/arm/include/asm/Kbuild. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Geert, > If you create an arm-specific <asm/sections.h>, you also have to remove the line > > generic-y += sections.h > > from arch/arm/include/asm/Kbuild. That, I didn't know about. Thank you. I'll submit a new patch on Monday. Chris
diff --git a/arch/arm/include/asm/sections.h b/arch/arm/include/asm/sections.h new file mode 100644 index 0000000..401eb3c2 --- /dev/null +++ b/arch/arm/include/asm/sections.h @@ -0,0 +1,8 @@ +#ifndef _ASM_ARM_SECTIONS_H +#define _ASM_ARM_SECTIONS_H + +#include <asm-generic/sections.h> + +extern char _edata_loc[]; + +#endif /* _ASM_ARM_SECTIONS_H */ diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index efdddcb..41ae2cc 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -34,7 +34,7 @@ * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off. */ #undef MODULES_VADDR -#define MODULES_VADDR (((unsigned long)_etext + ~PMD_MASK) & PMD_MASK) +#define MODULES_VADDR (((unsigned long)_edata_loc + ~PMD_MASK) & PMD_MASK) #endif #ifdef CONFIG_MMU diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4867f5d..dd5a56b 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1210,7 +1210,7 @@ static inline void prepare_page_table(void) #ifdef CONFIG_XIP_KERNEL /* The XIP kernel is mapped in the module area -- skip over it */ - addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK; + addr = ((unsigned long)_edata_loc + PMD_SIZE - 1) & PMD_MASK; #endif for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE) pmd_clear(pmd_off_k(addr)); @@ -1292,7 +1292,7 @@ static void __init devicemaps_init(const struct machine_desc *mdesc) #ifdef CONFIG_XIP_KERNEL map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK); map.virtual = MODULES_VADDR; - map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK; + map.length = ((unsigned long)_edata_loc - map.virtual + ~SECTION_MASK) & SECTION_MASK; map.type = MT_ROM; create_mapping(&map); #endif
For an XIP build, _edata_loc, not _etext, represents the end of the binary image that will be programmed into ROM and mapped into the MODULES_VADDR area. With an XIP kernel, nothing is loaded into RAM before boot, meaning you have to take into account the size of the entire binary image that was programmed, including the init data values that will be copied to RAM during kernel boot. This fixes the bug where you might lose the end of your kernel area after page table setup is complete. Signed-off-by: Chris Brandt <chris.brandt@renesas.com> --- v2 * Added change for MODULES_VADDR * Moved extern to new file asm/sections.h --- arch/arm/include/asm/sections.h | 8 ++++++++ arch/arm/kernel/module.c | 2 +- arch/arm/mm/mmu.c | 4 ++-- 3 files changed, 11 insertions(+), 3 deletions(-) create mode 100644 arch/arm/include/asm/sections.h