diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | sysdeps/arm/memcpy.S | 16 | ||||
| -rw-r--r-- | sysdeps/arm/memmove.S | 16 |
3 files changed, 32 insertions, 6 deletions
@@ -1,3 +1,9 @@ +2015-03-19 Roland McGrath <roland@hack.frob.com> + + * sysdeps/arm/memcpy.S [ARM_ALWAYS_BX]: Fix computed-jump calculations + to account for alignment padding. + * sysdeps/arm/memmove.S: Likewise. + 2015-03-19 Chris Metcalf <cmetcalf@ezchip.com> * sysdeps/unix/sysv/linux/generic/README: New file. diff --git a/sysdeps/arm/memcpy.S b/sysdeps/arm/memcpy.S index 0602d99..3e41ea6 100644 --- a/sysdeps/arm/memcpy.S +++ b/sysdeps/arm/memcpy.S @@ -125,7 +125,12 @@ ENTRY(memcpy) push {r10} cfi_adjust_cfa_offset (4) cfi_rel_offset (r10, 0) - add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) +0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) + /* If alignment is not perfect, then there will be some + padding (nop) instructions between this BX and label 6. + The computation above assumed that two instructions + later is exactly the right spot. */ + add r10, #(6f - (0b + PC_OFS)) bx r10 #endif .p2align ARM_BX_ALIGN_LOG2 @@ -156,11 +161,16 @@ ENTRY(memcpy) add pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) nop #else - add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) +0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) + /* If alignment is not perfect, then there will be some + padding (nop) instructions between this BX and label 66. + The computation above assumed that two instructions + later is exactly the right spot. */ + add r10, #(66f - (0b + PC_OFS)) bx r10 #endif .p2align ARM_BX_ALIGN_LOG2 - nop +66: nop .p2align ARM_BX_ALIGN_LOG2 sfi_breg r0, \ str r3, [\B], #4 diff --git a/sysdeps/arm/memmove.S b/sysdeps/arm/memmove.S index f8a4eff..dde877e 100644 --- a/sysdeps/arm/memmove.S +++ b/sysdeps/arm/memmove.S @@ -141,7 +141,12 @@ ENTRY(memmove) push {r10} cfi_adjust_cfa_offset (4) cfi_rel_offset (r10, 0) - add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) +0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) + /* If alignment is not perfect, then there will be some + padding (nop) instructions between this BX and label 6. + The computation above assumed that two instructions + later is exactly the right spot. */ + add r10, #(6f - (0b + PC_OFS)) bx r10 #endif .p2align ARM_BX_ALIGN_LOG2 @@ -172,11 +177,16 @@ ENTRY(memmove) add pc, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) nop #else - add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) +0: add r10, pc, ip, lsl #(ARM_BX_ALIGN_LOG2 - 2) + /* If alignment is not perfect, then there will be some + padding (nop) instructions between this BX and label 66. + The computation above assumed that two instructions + later is exactly the right spot. */ + add r10, #(66f - (0b + PC_OFS)) bx r10 #endif .p2align ARM_BX_ALIGN_LOG2 - nop +66: nop .p2align ARM_BX_ALIGN_LOG2 sfi_breg r0, \ str r3, [\B, #-4]! |