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Message-Id: <1295253729-23153-2-git-send-email-stanley.miao@windriver.com> Date: Mon, 17 Jan 2011 16:42:07 +0800 From: "Stanley.Miao" <stanley.miao@...driver.com> To: linux-kernel@...r.kernel.org Cc: linux-arm-kernel@...ts.infradead.org Subject: [PATCH 1/3] Support BE8 mode kernel modules relocation The code section in BE8 kernel modules is in little-endian while data section is in big-endian. When reading code from memory in the relocation procedure, these instructions are read according to big-endian, so they need to be inverted before writing to memory and after reading from memory. Signed-off-by: Stanley.Miao <stanley.miao@...driver.com> --- arch/arm/Makefile | 1 + arch/arm/include/asm/io.h | 12 ++++++++++ arch/arm/kernel/module.c | 51 ++++++++++++++++++++++++-------------------- 3 files changed, 41 insertions(+), 23 deletions(-) diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 3eec793..03e7761 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -13,6 +13,7 @@ LDFLAGS_vmlinux :=-p --no-undefined -X ifeq ($(CONFIG_CPU_ENDIAN_BE8),y) LDFLAGS_vmlinux += --be8 +LDFLAGS_MODULE += --be8 endif OBJCOPYFLAGS :=-O binary -R .note -R .note.gnu.build-id -R .comment -S diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h index 815efa2..2f088c5 100644 --- a/arch/arm/include/asm/io.h +++ b/arch/arm/include/asm/io.h @@ -233,6 +233,18 @@ extern void _memset_io(volatile void __iomem *, int, size_t); #endif /* __mem_pci */ +#ifdef CONFIG_CPU_ENDIAN_BE8 +#define read_instr32(c) __swab32(*(u32 *)c) +#define read_instr16(c) __swab16(*(u16 *)c) +#define write_instr32(v,a) (*(u32 *)(a) = __swab32((__force __u32)(v))) +#define write_instr16(v,a) (*(u16 *)(a) = __swab16((__force __u16)(v))) +#else +#define read_instr32(c) (*(u32 *)c) +#define read_instr16(c) (*(u16 *)c) +#define write_instr32(v,a) (*(u32 *)(a) = (v)) +#define write_instr16(v,a) (*(u16 *)(a) = (v)) +#endif + /* * ioremap and friends. * diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index d9bd786..9c58a0d 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -14,6 +14,7 @@ #include <linux/moduleloader.h> #include <linux/kernel.h> #include <linux/mm.h> +#include <linux/io.h> #include <linux/elf.h> #include <linux/vmalloc.h> #include <linux/fs.h> @@ -148,7 +149,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, case R_ARM_PC24: case R_ARM_CALL: case R_ARM_JUMP24: - offset = (*(u32 *)loc & 0x00ffffff) << 2; + offset = (read_instr32(loc) & 0x00ffffff) << 2; if (offset & 0x02000000) offset -= 0x04000000; @@ -165,8 +166,8 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, offset >>= 2; - *(u32 *)loc &= 0xff000000; - *(u32 *)loc |= offset & 0x00ffffff; + write_instr32((read_instr32(loc) & 0xff000000) | + (offset & 0x00ffffff), loc); break; case R_ARM_V4BX: @@ -174,9 +175,9 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, * other bits to re-code instruction as * MOV PC,Rm. */ - *(u32 *)loc &= 0xf000000f; - *(u32 *)loc |= 0x01a0f000; - break; + write_instr32((read_instr32(loc) & 0xf000000f) | + 0x01a0f000, loc); + break; case R_ARM_PREL31: offset = *(u32 *)loc + sym->st_value - loc; @@ -185,7 +186,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, case R_ARM_MOVW_ABS_NC: case R_ARM_MOVT_ABS: - offset = *(u32 *)loc; + offset = read_instr32(loc); offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff); offset = (offset ^ 0x8000) - 0x8000; @@ -193,16 +194,16 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS) offset >>= 16; - *(u32 *)loc &= 0xfff0f000; - *(u32 *)loc |= ((offset & 0xf000) << 4) | - (offset & 0x0fff); + write_instr32((read_instr32(loc) & 0xfff0f000) | + ((offset & 0xf000) << 4) | + (offset & 0x0fff), loc); break; #ifdef CONFIG_THUMB2_KERNEL case R_ARM_THM_CALL: case R_ARM_THM_JUMP24: - upper = *(u16 *)loc; - lower = *(u16 *)(loc + 2); + upper = read_instr16(loc); + lower = read_instr16(loc + 2); /* * 25 bit signed address range (Thumb-2 BL and B.W @@ -242,17 +243,19 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, sign = (offset >> 24) & 1; j1 = sign ^ (~(offset >> 23) & 1); j2 = sign ^ (~(offset >> 22) & 1); - *(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) | - ((offset >> 12) & 0x03ff)); - *(u16 *)(loc + 2) = (u16)((lower & 0xd000) | - (j1 << 13) | (j2 << 11) | - ((offset >> 1) & 0x07ff)); + write_instr16((u16)((upper & 0xf800) | (sign << 10) | + ((offset >> 12) & 0x03ff)), + loc); + write_instr16((u16)((lower & 0xd000) | + (j1 << 13) | (j2 << 11) | + ((offset >> 1) & 0x07ff)), + loc + 2); break; case R_ARM_THM_MOVW_ABS_NC: case R_ARM_THM_MOVT_ABS: - upper = *(u16 *)loc; - lower = *(u16 *)(loc + 2); + upper = read_instr16(loc); + lower = read_instr16(loc + 2); /* * MOVT/MOVW instructions encoding in Thumb-2: @@ -273,12 +276,14 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS) offset >>= 16; - *(u16 *)loc = (u16)((upper & 0xfbf0) | + write_instr16((u16)((upper & 0xfbf0) | ((offset & 0xf000) >> 12) | - ((offset & 0x0800) >> 1)); - *(u16 *)(loc + 2) = (u16)((lower & 0x8f00) | + ((offset & 0x0800) >> 1)), + doc); + write_instr16((u16)((lower & 0x8f00) | ((offset & 0x0700) << 4) | - (offset & 0x00ff)); + (offset & 0x00ff)), + doc + 2); break; #endif -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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