Copying a function with memcpy() and then trying to execute the result isn't trivially portable to Thumb.
This patch modifies the kexec soft restart code to copy its assembler trampoline relocate_new_kernel() using fncpy() instead, so that relocate_new_kernel can be in the same ISA as the rest of the kernel without problems.
Signed-off-by: Dave Martin Dave.Martin@arm.com --- Changes since v1:
* Move ENDPROC() after relocate_new_kernel's literals, to be consistent the location of relocate_new_kernel_end and with the way GCC sets ELF symbol sizes for functions. This is just a tidyup, with no functional impact.
arch/arm/kernel/machine_kexec.c | 17 ++++++++++------- arch/arm/kernel/relocate_kernel.S | 8 ++++++-- 2 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 57221e3..f0d180d 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -14,11 +14,12 @@ #include <asm/pgalloc.h> #include <asm/mmu_context.h> #include <asm/cacheflush.h> +#include <asm/fncpy.h> #include <asm/mach-types.h> #include <asm/smp_plat.h> #include <asm/system_misc.h>
-extern const unsigned char relocate_new_kernel[]; +extern void relocate_new_kernel(void); extern const unsigned int relocate_new_kernel_size;
extern unsigned long kexec_start_address; @@ -142,6 +143,8 @@ void machine_kexec(struct kimage *image) { unsigned long page_list; unsigned long reboot_code_buffer_phys; + unsigned long reboot_entry = (unsigned long)relocate_new_kernel; + unsigned long reboot_entry_phys; void *reboot_code_buffer;
/* @@ -168,16 +171,16 @@ void machine_kexec(struct kimage *image)
/* copy our kernel relocation code to the control code page */ - memcpy(reboot_code_buffer, - relocate_new_kernel, relocate_new_kernel_size); + reboot_entry = fncpy(reboot_code_buffer, + reboot_entry, + relocate_new_kernel_size); + reboot_entry_phys = (unsigned long)reboot_entry + + (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer);
- - flush_icache_range((unsigned long) reboot_code_buffer, - (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE); printk(KERN_INFO "Bye!\n");
if (kexec_reinit) kexec_reinit();
- soft_restart(reboot_code_buffer_phys); + soft_restart(reboot_entry_phys); } diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S index d0cdedf..9585896 100644 --- a/arch/arm/kernel/relocate_kernel.S +++ b/arch/arm/kernel/relocate_kernel.S @@ -2,10 +2,12 @@ * relocate_kernel.S - put the kernel image in place to boot */
+#include <linux/linkage.h> #include <asm/kexec.h>
- .globl relocate_new_kernel -relocate_new_kernel: + .align 3 /* not needed for this code, but keeps fncpy() happy */ + +ENTRY(relocate_new_kernel)
ldr r0,kexec_indirection_page ldr r1,kexec_start_address @@ -79,6 +81,8 @@ kexec_mach_type: kexec_boot_atags: .long 0x0
+ENDPROC(relocate_new_kernel) + relocate_new_kernel_end:
.globl relocate_new_kernel_size