2dede2d8e9
Patch from Nicolas Pitre The ARM EABI says that the stack pointer has to be 64-bit aligned for reasons already mentioned in patch #3101 when calling C functions. We therefore must verify and adjust sp accordingly when taking an exception from kernel mode since sp might not necessarily be 64-bit aligned if the exception occurs in the middle of a kernel function. If the exception occurs while in user mode then no sp fixup is needed as long as sizeof(struct pt_regs) as well as any additional syscall data stack space remain multiples of 8. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
85 lines
1.6 KiB
ArmAsm
85 lines
1.6 KiB
ArmAsm
#include <linux/config.h>
|
|
#include <linux/init.h>
|
|
#include <linux/linkage.h>
|
|
|
|
#include <asm/assembler.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/thread_info.h>
|
|
|
|
@ Bad Abort numbers
|
|
@ -----------------
|
|
@
|
|
#define BAD_PREFETCH 0
|
|
#define BAD_DATA 1
|
|
#define BAD_ADDREXCPTN 2
|
|
#define BAD_IRQ 3
|
|
#define BAD_UNDEFINSTR 4
|
|
|
|
@
|
|
@ Most of the stack format comes from struct pt_regs, but with
|
|
@ the addition of 8 bytes for storing syscall args 5 and 6.
|
|
@ This _must_ remain a multiple of 8 for EABI.
|
|
@
|
|
#define S_OFF 8
|
|
|
|
/*
|
|
* The SWI code relies on the fact that R0 is at the bottom of the stack
|
|
* (due to slow/fast restore user regs).
|
|
*/
|
|
#if S_R0 != 0
|
|
#error "Please fix"
|
|
#endif
|
|
|
|
.macro zero_fp
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
mov fp, #0
|
|
#endif
|
|
.endm
|
|
|
|
#if __LINUX_ARM_ARCH__ >= 6
|
|
.macro disable_irq
|
|
cpsid i
|
|
.endm
|
|
|
|
.macro enable_irq
|
|
cpsie i
|
|
.endm
|
|
#else
|
|
.macro disable_irq
|
|
msr cpsr_c, #PSR_I_BIT | SVC_MODE
|
|
.endm
|
|
|
|
.macro enable_irq
|
|
msr cpsr_c, #SVC_MODE
|
|
.endm
|
|
#endif
|
|
|
|
.macro get_thread_info, rd
|
|
mov \rd, sp, lsr #13
|
|
mov \rd, \rd, lsl #13
|
|
.endm
|
|
|
|
.macro alignment_trap, rtemp
|
|
#ifdef CONFIG_ALIGNMENT_TRAP
|
|
ldr \rtemp, .LCcralign
|
|
ldr \rtemp, [\rtemp]
|
|
mcr p15, 0, \rtemp, c1, c0
|
|
#endif
|
|
.endm
|
|
|
|
|
|
/*
|
|
* These are the registers used in the syscall handler, and allow us to
|
|
* have in theory up to 7 arguments to a function - r0 to r6.
|
|
*
|
|
* r7 is reserved for the system call number for thumb mode.
|
|
*
|
|
* Note that tbl == why is intentional.
|
|
*
|
|
* We must set at least "tsk" and "why" when calling ret_with_reschedule.
|
|
*/
|
|
scno .req r7 @ syscall number
|
|
tbl .req r8 @ syscall table pointer
|
|
why .req r8 @ Linux syscall (!= 0)
|
|
tsk .req r9 @ current thread_info
|