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Commit f592d323 authored by Ben Dooks's avatar Ben Dooks
Browse files

ARM: module: correctly relocate instructions in BE8 



When in BE8 mode, our instructions are not in the same ordering as the
data, so use <asm/opcodes.h> to take this into account.

Note, also requires modules to be built --be8

Signed-off-by: default avatarBen Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: default avatarDave Martin <Dave.Martin@arm.com>
parent a79a0cb1

arch/arm/kernel/module.c

+34 −23
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <asm/sections.h>

#include <asm/smp_plat.h>

#include <asm/unwind.h>

#include <asm/opcodes.h>



#ifdef CONFIG_XIP_KERNEL

/*
@@ -60,6 +61,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 
		Elf32_Sym *sym;

		const char *symname;

		s32 offset;

		u32 tmp;

#ifdef CONFIG_THUMB2_KERNEL

		u32 upper, lower, sign, j1, j2;

#endif
@@ -95,7 +97,8 @@ 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 = __mem_to_opcode_arm(*(u32 *)loc);

			offset = (offset & 0x00ffffff) << 2;

			if (offset & 0x02000000)

				offset -= 0x04000000;
@@ -111,9 +114,10 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, 
			}



			offset >>= 2;

			offset &= 0x00ffffff;



			*(u32 *)loc &= 0xff000000;

			*(u32 *)loc |= offset & 0x00ffffff;

			*(u32 *)loc &= __opcode_to_mem_arm(0xff000000);

			*(u32 *)loc |= __opcode_to_mem_arm(offset);

			break;



	       case R_ARM_V4BX:
@@ -121,8 +125,8 @@ 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;

		       *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f);

		       *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000);

		       break;



		case R_ARM_PREL31:
@@ -132,7 +136,7 @@ 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 = tmp = __mem_to_opcode_arm(*(u32 *)loc);

			offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);

			offset = (offset ^ 0x8000) - 0x8000;
@@ -140,16 +144,18 @@ 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) |

			tmp &= 0xfff0f000;

			tmp |= ((offset & 0xf000) << 4) |

				(offset & 0x0fff);



			*(u32 *)loc = __opcode_to_mem_arm(tmp);

			break;



#ifdef CONFIG_THUMB2_KERNEL

		case R_ARM_THM_CALL:

		case R_ARM_THM_JUMP24:

			upper = *(u16 *)loc;

			lower = *(u16 *)(loc + 2);

			upper = __mem_to_opcode_thumb16(*(u16 *)loc);

			lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));



			/*

			 * 25 bit signed address range (Thumb-2 BL and B.W
@@ -198,17 +204,20 @@ 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) |

			upper = (u16)((upper & 0xf800) | (sign << 10) |

					    ((offset >> 12) & 0x03ff));

			*(u16 *)(loc + 2) = (u16)((lower & 0xd000) |

			lower = (u16)((lower & 0xd000) |

				      (j1 << 13) | (j2 << 11) |

				      ((offset >> 1) & 0x07ff));



			*(u16 *)loc = __opcode_to_mem_thumb16(upper);

			*(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);

			break;



		case R_ARM_THM_MOVW_ABS_NC:

		case R_ARM_THM_MOVT_ABS:

			upper = *(u16 *)loc;

			lower = *(u16 *)(loc + 2);

			upper = __mem_to_opcode_thumb16(*(u16 *)loc);

			lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));



			/*

			 * MOVT/MOVW instructions encoding in Thumb-2:
@@ -229,12 +238,14 @@ 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) |

			upper = (u16)((upper & 0xfbf0) |

				      ((offset & 0xf000) >> 12) |

				      ((offset & 0x0800) >> 1));

			*(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |

			lower = (u16)((lower & 0x8f00) |

				      ((offset & 0x0700) << 4) |

				      (offset & 0x00ff));

			*(u16 *)loc = __opcode_to_mem_thumb16(upper);

			*(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);

			break;

#endif