This adds aarch64 support for relocating binaries linked with -pie.
Support is integrated into the already exisiting
relocate_to_current_adr() function which is now used for both arm32
and aarch64.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
arch/arm/cpu/common.c | 38 ++++++++++++++++++++++++-------
arch/arm/cpu/setupc_64.S | 58 ++++++++++++++++++++++++++++++++++++++++++++++++
common/Kconfig | 2 +-
3 files changed, 89 insertions(+), 9 deletions(-)
diff --git a/arch/arm/cpu/common.c b/arch/arm/cpu/common.c
index 3766116d97..c317e502d0 100644
--- a/arch/arm/cpu/common.c
+++ b/arch/arm/cpu/common.c
@@ -24,39 +24,61 @@
#include <asm-generic/memory_layout.h>
#include <asm/sections.h>
#include <asm/cache.h>
+#include <debug_ll.h>
+
+#define R_ARM_RELATIVE 23
+#define R_AARCH64_RELATIVE 1027
/*
* relocate binary to the currently running address
*/
void relocate_to_current_adr(void)
{
- unsigned long offset;
+ unsigned long offset, offset_var;
unsigned long *dstart, *dend, *dynsym, *dynend;
/* Get offset between linked address and runtime address */
offset = get_runtime_offset();
+ offset_var = global_variable_offset();
- dstart = (void *)__rel_dyn_start + offset;
- dend = (void *)__rel_dyn_end + offset;
+ dstart = (void *)__rel_dyn_start + offset_var;
+ dend = (void *)__rel_dyn_end + offset_var;
- dynsym = (void *)__dynsym_start + offset;
- dynend = (void *)__dynsym_end + offset;
+ dynsym = (void *)__dynsym_start + offset_var;
+ dynend = (void *)__dynsym_end + offset_var;
while (dstart < dend) {
unsigned long *fixup = (unsigned long *)(*dstart + offset);
unsigned long type = *(dstart + 1);
+ int add;
+
+ if (ELF64_R_TYPE(type) == R_AARCH64_RELATIVE) {
+ unsigned long addend = *(dstart + 2);
- if ((type & 0xff) == 0x17) {
+ *fixup = addend + offset;
+
+ add = 3;
+ } else if (ELF32_R_TYPE(type) == R_ARM_RELATIVE) {
*fixup = *fixup + offset;
- } else {
+
+ add = 2;
+ } else if (ELF32_R_TYPE(type) == R_ARM_ABS32) {
int index = type >> 8;
unsigned long r = dynsym[index * 4 + 1];
*fixup = *fixup + r + offset;
+
+ add = 2;
+ } else {
+ putc_ll('>');
+ puthex_ll(type);
+ putc_ll('\n');
+ /* We're doomed */
+ panic(NULL);
}
*dstart += offset;
- dstart += 2;
+ dstart += add;
}
memset(dynsym, 0, (unsigned long)dynend - (unsigned long)dynsym);
diff --git a/arch/arm/cpu/setupc_64.S b/arch/arm/cpu/setupc_64.S
index 3515854784..88c7899205 100644
--- a/arch/arm/cpu/setupc_64.S
+++ b/arch/arm/cpu/setupc_64.S
@@ -16,3 +16,61 @@ ENTRY(setup_c)
mov x30, x15
ret
ENDPROC(setup_c)
+
+/*
+ * void relocate_to_adr(unsigned long targetadr)
+ *
+ * Copy binary to targetadr, relocate code and continue
+ * executing at new address.
+ */
+.section .text.relocate_to_adr
+ENTRY(relocate_to_adr)
+ /* x0: target address */
+
+ stp x19, x20, [sp, #-16]!
+
+ mov x19, lr
+
+ mov x6, x0
+
+ bl get_runtime_offset
+ mov x5, x0
+
+ ldr x0, =_text
+ mov x8, x0
+
+ add x1, x0, x5 /* x1: from address */
+
+ cmp x1, x6 /* already at correct address? */
+ beq 1f /* yes, skip copy to new address */
+
+ ldr x2, =__bss_start
+
+ sub x2, x2, x0 /* x2: size */
+ mov x0, x6 /* x0: target */
+
+ /* adjust return address */
+ sub x19, x19, x1 /* sub address where we are actually running */
+ add x19, x19, x0 /* add address where we are going to run */
+
+ bl memcpy /* copy binary */
+
+#ifdef CONFIG_MMU
+ bl arm_early_mmu_cache_flush
+#endif
+ mov x0,#0
+ ic ivau, x0 /* flush icache */
+
+ ldr x0,=1f
+ sub x0, x0, x8
+ add x0, x0, x6
+ br x0 /* jump to relocated address */
+1:
+ bl relocate_to_current_adr /* relocate binary */
+
+ mov lr, x19
+
+ ldp x19, x20, [sp], #16
+ ret
+
+ENDPROC(relocate_to_adr)
diff --git a/common/Kconfig b/common/Kconfig
index af71d6888a..b7000c4d73 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -344,7 +344,7 @@ config KALLSYMS
This is useful to print a nice backtrace when an exception occurs.
config RELOCATABLE
- depends on PPC || (ARM && !CPU_V8)
+ depends on PPC || ARM
bool "generate relocatable barebox binary"
help
A non relocatable barebox binary will run at it's compiled in
--
2.16.1
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