| Message ID | 20161206195312.22354-2-f.fainelli@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/6/2016, Florian Fainelli wrote: > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 4001dd15818d..18ef688a796e 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -1437,12 +1437,8 @@ static void __init kmap_init(void) > static void __init map_lowmem(void) > { > struct memblock_region *reg; > -#ifdef CONFIG_XIP_KERNEL > - phys_addr_t kernel_x_start = round_down(__pa(_sdata), SECTION_SIZE); > -#else > - phys_addr_t kernel_x_start = round_down(__pa(_stext), SECTION_SIZE); > -#endif > - phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); > + phys_addr_t kernel_x_start = round_down(__pa(KERNEL_START), > SECTION_SIZE); > + phys_addr_t kernel_x_end = round_down(__pa(_end), SECTION_SIZE); Why are you changing the end of executable kernel (hence the 'x' in kernel_x_end) from __init_end to _end which basically maps the entire kernel image including text and data? Doing so would then change data from MT_MEMORY_RW into MT_MEMORY_RWX. I would think it would create some type of security risk to allow data to be executable.
On 12/06/2016 02:43 PM, Chris Brandt wrote: > On 12/6/2016, Florian Fainelli wrote: >> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c >> index 4001dd15818d..18ef688a796e 100644 >> --- a/arch/arm/mm/mmu.c >> +++ b/arch/arm/mm/mmu.c >> @@ -1437,12 +1437,8 @@ static void __init kmap_init(void) >> static void __init map_lowmem(void) >> { >> struct memblock_region *reg; >> -#ifdef CONFIG_XIP_KERNEL >> - phys_addr_t kernel_x_start = round_down(__pa(_sdata), SECTION_SIZE); >> -#else >> - phys_addr_t kernel_x_start = round_down(__pa(_stext), SECTION_SIZE); >> -#endif >> - phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); >> + phys_addr_t kernel_x_start = round_down(__pa(KERNEL_START), >> SECTION_SIZE); >> + phys_addr_t kernel_x_end = round_down(__pa(_end), SECTION_SIZE); > > Why are you changing the end of executable kernel (hence the 'x' in > kernel_x_end) from __init_end to _end which basically maps the entire > kernel image including text and data? That's a typo, was not intentional thanks for spotting it.
Hi Florian,
[auto build test WARNING on linus/master]
[also build test WARNING on v4.9-rc8 next-20161206]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Florian-Fainelli/ARM-Add-support-for-CONFIG_DEBUG_VIRTUAL/20161207-071442
config: arm-lart_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All warnings (new ones prefixed by >>):
>> drivers/mtd/devices/lart.c:83:0: warning: "KERNEL_START" redefined
#define KERNEL_START (BLOB_START + BLOB_LEN)
In file included from arch/arm/include/asm/page.h:163:0,
from arch/arm/include/asm/thread_info.h:17,
from include/linux/thread_info.h:58,
from include/asm-generic/preempt.h:4,
from ./arch/arm/include/generated/asm/preempt.h:1,
from include/linux/preempt.h:59,
from include/linux/spinlock.h:50,
from include/linux/seqlock.h:35,
from include/linux/time.h:5,
from include/linux/stat.h:18,
from include/linux/module.h:10,
from drivers/mtd/devices/lart.c:38:
arch/arm/include/asm/memory.h:117:0: note: this is the location of the previous definition
#define KERNEL_START _stext
vim +/KERNEL_START +83 drivers/mtd/devices/lart.c
^1da177e Linus Torvalds 2005-04-16 67
^1da177e Linus Torvalds 2005-04-16 68 /*
^1da177e Linus Torvalds 2005-04-16 69 * These values are specific to LART
^1da177e Linus Torvalds 2005-04-16 70 */
^1da177e Linus Torvalds 2005-04-16 71
^1da177e Linus Torvalds 2005-04-16 72 /* general */
^1da177e Linus Torvalds 2005-04-16 73 #define BUSWIDTH 4 /* don't change this - a lot of the code _will_ break if you change this */
^1da177e Linus Torvalds 2005-04-16 74 #define FLASH_OFFSET 0xe8000000 /* see linux/arch/arm/mach-sa1100/lart.c */
^1da177e Linus Torvalds 2005-04-16 75
^1da177e Linus Torvalds 2005-04-16 76 /* blob */
^1da177e Linus Torvalds 2005-04-16 77 #define NUM_BLOB_BLOCKS FLASH_NUMBLOCKS_16m_PARAM
^1da177e Linus Torvalds 2005-04-16 78 #define BLOB_START 0x00000000
^1da177e Linus Torvalds 2005-04-16 79 #define BLOB_LEN (NUM_BLOB_BLOCKS * FLASH_BLOCKSIZE_PARAM)
^1da177e Linus Torvalds 2005-04-16 80
^1da177e Linus Torvalds 2005-04-16 81 /* kernel */
^1da177e Linus Torvalds 2005-04-16 82 #define NUM_KERNEL_BLOCKS 7
^1da177e Linus Torvalds 2005-04-16 @83 #define KERNEL_START (BLOB_START + BLOB_LEN)
^1da177e Linus Torvalds 2005-04-16 84 #define KERNEL_LEN (NUM_KERNEL_BLOCKS * FLASH_BLOCKSIZE_MAIN)
^1da177e Linus Torvalds 2005-04-16 85
^1da177e Linus Torvalds 2005-04-16 86 /* initial ramdisk */
^1da177e Linus Torvalds 2005-04-16 87 #define NUM_INITRD_BLOCKS 24
^1da177e Linus Torvalds 2005-04-16 88 #define INITRD_START (KERNEL_START + KERNEL_LEN)
^1da177e Linus Torvalds 2005-04-16 89 #define INITRD_LEN (NUM_INITRD_BLOCKS * FLASH_BLOCKSIZE_MAIN)
^1da177e Linus Torvalds 2005-04-16 90
^1da177e Linus Torvalds 2005-04-16 91 /*
:::::: The code at line 83 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2
:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 76cbd9c674df..bee7511c5098 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -111,6 +111,13 @@ #endif /* !CONFIG_MMU */ +#ifdef CONFIG_XIP_KERNEL +#define KERNEL_START _sdata +#else +#define KERNEL_START _stext +#endif +#define KERNEL_END _end + /* * We fix the TCM memories max 32 KiB ITCM resp DTCM at these * locations diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 370581aeb871..c87d0d5b65f2 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -230,11 +230,8 @@ phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) void __init arm_memblock_init(const struct machine_desc *mdesc) { /* Register the kernel text, kernel data and initrd with memblock. */ -#ifdef CONFIG_XIP_KERNEL - memblock_reserve(__pa(_sdata), _end - _sdata); -#else - memblock_reserve(__pa(_stext), _end - _stext); -#endif + memblock_reserve(__pa(KERNEL_START), _end - KERNEL_START); + #ifdef CONFIG_BLK_DEV_INITRD /* FDT scan will populate initrd_start */ if (initrd_start && !phys_initrd_size) { diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4001dd15818d..18ef688a796e 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1437,12 +1437,8 @@ static void __init kmap_init(void) static void __init map_lowmem(void) { struct memblock_region *reg; -#ifdef CONFIG_XIP_KERNEL - phys_addr_t kernel_x_start = round_down(__pa(_sdata), SECTION_SIZE); -#else - phys_addr_t kernel_x_start = round_down(__pa(_stext), SECTION_SIZE); -#endif - phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); + phys_addr_t kernel_x_start = round_down(__pa(KERNEL_START), SECTION_SIZE); + phys_addr_t kernel_x_end = round_down(__pa(_end), SECTION_SIZE); /* Map all the lowmem memory banks. */ for_each_memblock(memory, reg) {
In preparation for adding CONFIG_DEBUG_VIRTUAL support, define a set of common constants: KERNEL_START and KERNEL_END which abstract CONFIG_XIP_KERNEL vs. !CONFIG_XIP_KERNEL. Update the code where relevant. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- arch/arm/include/asm/memory.h | 7 +++++++ arch/arm/mm/init.c | 7 ++----- arch/arm/mm/mmu.c | 8 ++------ 3 files changed, 11 insertions(+), 11 deletions(-)