arm-trusted-firmware/bl32/tsp/aarch64/tsp_exceptions.S
Jeenu Viswambharan a806dad58c Define and use no_ret macro where no return is expected
There are many instances in ARM Trusted Firmware where control is
transferred to functions from which return isn't expected. Such jumps
are made using 'bl' instruction to provide the callee with the location
from which it was jumped to. Additionally, debuggers infer the caller by
examining where 'lr' register points to. If a 'bl' of the nature
described above falls at the end of an assembly function, 'lr' will be
left pointing to a location outside of the function range. This misleads
the debugger back trace.

This patch defines a 'no_ret' macro to be used when jumping to functions
from which return isn't expected. The macro ensures to use 'bl'
instruction for the jump, and also, for debug builds, places a 'nop'
instruction immediately thereafter (unless instructed otherwise) so as
to leave 'lr' pointing within the function range.

Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
2016-12-05 14:55:35 +00:00

187 lines
5.5 KiB
ArmAsm

/*
* Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#include <asm_macros.S>
#include <bl_common.h>
#include <tsp.h>
/* ----------------------------------------------------
* The caller-saved registers x0-x18 and LR are saved
* here.
* ----------------------------------------------------
*/
#define SCRATCH_REG_SIZE #(20 * 8)
.macro save_caller_regs_and_lr
sub sp, sp, SCRATCH_REG_SIZE
stp x0, x1, [sp]
stp x2, x3, [sp, #0x10]
stp x4, x5, [sp, #0x20]
stp x6, x7, [sp, #0x30]
stp x8, x9, [sp, #0x40]
stp x10, x11, [sp, #0x50]
stp x12, x13, [sp, #0x60]
stp x14, x15, [sp, #0x70]
stp x16, x17, [sp, #0x80]
stp x18, x30, [sp, #0x90]
.endm
.macro restore_caller_regs_and_lr
ldp x0, x1, [sp]
ldp x2, x3, [sp, #0x10]
ldp x4, x5, [sp, #0x20]
ldp x6, x7, [sp, #0x30]
ldp x8, x9, [sp, #0x40]
ldp x10, x11, [sp, #0x50]
ldp x12, x13, [sp, #0x60]
ldp x14, x15, [sp, #0x70]
ldp x16, x17, [sp, #0x80]
ldp x18, x30, [sp, #0x90]
add sp, sp, SCRATCH_REG_SIZE
.endm
/* ----------------------------------------------------
* Common TSP interrupt handling routine
* ----------------------------------------------------
*/
.macro handle_tsp_interrupt label
/* Enable the SError interrupt */
msr daifclr, #DAIF_ABT_BIT
save_caller_regs_and_lr
bl tsp_common_int_handler
cbz x0, interrupt_exit_\label
/*
* This interrupt was not targetted to S-EL1 so send it to
* the monitor and wait for execution to resume.
*/
smc #0
interrupt_exit_\label:
restore_caller_regs_and_lr
eret
.endm
.globl tsp_exceptions
/* -----------------------------------------------------
* TSP exception handlers.
* -----------------------------------------------------
*/
vector_base tsp_exceptions
/* -----------------------------------------------------
* Current EL with _sp_el0 : 0x0 - 0x200. No exceptions
* are expected and treated as irrecoverable errors.
* -----------------------------------------------------
*/
vector_entry sync_exception_sp_el0
no_ret plat_panic_handler
check_vector_size sync_exception_sp_el0
vector_entry irq_sp_el0
no_ret plat_panic_handler
check_vector_size irq_sp_el0
vector_entry fiq_sp_el0
no_ret plat_panic_handler
check_vector_size fiq_sp_el0
vector_entry serror_sp_el0
no_ret plat_panic_handler
check_vector_size serror_sp_el0
/* -----------------------------------------------------
* Current EL with SPx: 0x200 - 0x400. Only IRQs/FIQs
* are expected and handled
* -----------------------------------------------------
*/
vector_entry sync_exception_sp_elx
no_ret plat_panic_handler
check_vector_size sync_exception_sp_elx
vector_entry irq_sp_elx
handle_tsp_interrupt irq_sp_elx
check_vector_size irq_sp_elx
vector_entry fiq_sp_elx
handle_tsp_interrupt fiq_sp_elx
check_vector_size fiq_sp_elx
vector_entry serror_sp_elx
no_ret plat_panic_handler
check_vector_size serror_sp_elx
/* -----------------------------------------------------
* Lower EL using AArch64 : 0x400 - 0x600. No exceptions
* are handled since TSP does not implement a lower EL
* -----------------------------------------------------
*/
vector_entry sync_exception_aarch64
no_ret plat_panic_handler
check_vector_size sync_exception_aarch64
vector_entry irq_aarch64
no_ret plat_panic_handler
check_vector_size irq_aarch64
vector_entry fiq_aarch64
no_ret plat_panic_handler
check_vector_size fiq_aarch64
vector_entry serror_aarch64
no_ret plat_panic_handler
check_vector_size serror_aarch64
/* -----------------------------------------------------
* Lower EL using AArch32 : 0x600 - 0x800. No exceptions
* handled since the TSP does not implement a lower EL.
* -----------------------------------------------------
*/
vector_entry sync_exception_aarch32
no_ret plat_panic_handler
check_vector_size sync_exception_aarch32
vector_entry irq_aarch32
no_ret plat_panic_handler
check_vector_size irq_aarch32
vector_entry fiq_aarch32
no_ret plat_panic_handler
check_vector_size fiq_aarch32
vector_entry serror_aarch32
no_ret plat_panic_handler
check_vector_size serror_aarch32