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Commit a806dad5 authored by Jeenu Viswambharan's avatar Jeenu Viswambharan
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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: default avatarDouglas Raillard <douglas.raillard@arm.com>
Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
parent c59428b1
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Inline Side-by-side
bl1/aarch64/bl1_exceptions.S
View file @ a806dad5
......@@ -49,25 +49,25 @@ vector_base bl1_exceptions
vector_entry SynchronousExceptionSP0
mov x0, #SYNC_EXCEPTION_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionSP0
vector_entry IrqSP0
mov x0, #IRQ_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqSP0
vector_entry FiqSP0
mov x0, #FIQ_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqSP0
vector_entry SErrorSP0
mov x0, #SERROR_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorSP0
/* -----------------------------------------------------
......@@ -77,25 +77,25 @@ vector_entry SErrorSP0
vector_entry SynchronousExceptionSPx
mov x0, #SYNC_EXCEPTION_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionSPx
vector_entry IrqSPx
mov x0, #IRQ_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqSPx
vector_entry FiqSPx
mov x0, #FIQ_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqSPx
vector_entry SErrorSPx
mov x0, #SERROR_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorSPx
/* -----------------------------------------------------
......@@ -120,19 +120,19 @@ vector_entry SynchronousExceptionA64
vector_entry IrqA64
mov x0, #IRQ_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqA64
vector_entry FiqA64
mov x0, #FIQ_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqA64
vector_entry SErrorA64
mov x0, #SERROR_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorA64
/* -----------------------------------------------------
......@@ -142,25 +142,25 @@ vector_entry SErrorA64
vector_entry SynchronousExceptionA32
mov x0, #SYNC_EXCEPTION_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionA32
vector_entry IrqA32
mov x0, #IRQ_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqA32
vector_entry FiqA32
mov x0, #FIQ_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqA32
vector_entry SErrorA32
mov x0, #SERROR_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorA32
......@@ -231,7 +231,7 @@ endfunc smc_handler64
unexpected_sync_exception:
mov x0, #SYNC_EXCEPTION_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
/* -----------------------------------------------------
* Save Secure/Normal world context and jump to
......
bl2/aarch32/bl2_entrypoint.S
View file @ a806dad5
......@@ -140,6 +140,6 @@ func bl2_entrypoint
* Should never reach this point.
* ---------------------------------------------
*/
bl plat_panic_handler
no_ret plat_panic_handler
endfunc bl2_entrypoint
bl2/aarch64/bl2_entrypoint.S
View file @ a806dad5
......@@ -131,6 +131,6 @@ func bl2_entrypoint
* Should never reach this point.
* ---------------------------------------------
*/
bl plat_panic_handler
no_ret plat_panic_handler
endfunc bl2_entrypoint
bl2u/aarch64/bl2u_entrypoint.S
View file @ a806dad5
......@@ -126,6 +126,6 @@ func bl2u_entrypoint
* Should never reach this point.
* ---------------------------------------------
*/
bl plat_panic_handler
no_ret plat_panic_handler
endfunc bl2u_entrypoint
bl31/aarch64/crash_reporting.S
View file @ a806dad5
......@@ -350,17 +350,17 @@ func do_crash_reporting
plat_crash_print_regs
/* Done reporting */
bl plat_panic_handler
no_ret plat_panic_handler
endfunc do_crash_reporting
#else /* CRASH_REPORTING */
func report_unhandled_exception
report_unhandled_interrupt:
bl plat_panic_handler
no_ret plat_panic_handler
endfunc report_unhandled_exception
#endif /* CRASH_REPORTING */
func crash_panic
bl plat_panic_handler
no_ret plat_panic_handler
endfunc crash_panic
bl31/aarch64/runtime_exceptions.S
View file @ a806dad5
......@@ -73,7 +73,7 @@
b.eq smc_handler64
/* Other kinds of synchronous exceptions are not handled */
bl report_unhandled_exception
no_ret report_unhandled_exception
.endm
......@@ -176,7 +176,7 @@ vector_base runtime_exceptions
*/
vector_entry sync_exception_sp_el0
/* We don't expect any synchronous exceptions from EL3 */
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size sync_exception_sp_el0
vector_entry irq_sp_el0
......@@ -184,17 +184,17 @@ vector_entry irq_sp_el0
* EL3 code is non-reentrant. Any asynchronous exception is a serious
* error. Loop infinitely.
*/
bl report_unhandled_interrupt
no_ret report_unhandled_interrupt
check_vector_size irq_sp_el0
vector_entry fiq_sp_el0
bl report_unhandled_interrupt
no_ret report_unhandled_interrupt
check_vector_size fiq_sp_el0
vector_entry serror_sp_el0
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size serror_sp_el0
/* ---------------------------------------------------------------------
......@@ -208,19 +208,19 @@ vector_entry sync_exception_sp_elx
* synchronous exception. There is a high probability that SP_EL3 is
* corrupted.
*/
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size sync_exception_sp_elx
vector_entry irq_sp_elx
bl report_unhandled_interrupt
no_ret report_unhandled_interrupt
check_vector_size irq_sp_elx
vector_entry fiq_sp_elx
bl report_unhandled_interrupt
no_ret report_unhandled_interrupt
check_vector_size fiq_sp_elx
vector_entry serror_sp_elx
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size serror_sp_elx
/* ---------------------------------------------------------------------
......@@ -250,7 +250,7 @@ vector_entry serror_aarch64
* SError exceptions from lower ELs are not currently supported.
* Report their occurrence.
*/
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size serror_aarch64
/* ---------------------------------------------------------------------
......@@ -280,7 +280,7 @@ vector_entry serror_aarch32
* SError exceptions from lower ELs are not currently supported.
* Report their occurrence.
*/
bl report_unhandled_exception
no_ret report_unhandled_exception
check_vector_size serror_aarch32
......@@ -415,5 +415,5 @@ smc_prohibited:
rt_svc_fw_critical_error:
/* Switch to SP_ELx */
msr spsel, #1
bl report_unhandled_exception
no_ret report_unhandled_exception
endfunc smc_handler
bl32/tsp/aarch64/tsp_entrypoint.S
View file @ a806dad5
......@@ -391,7 +391,7 @@ tsp_sel1_intr_return:
/* Should never reach here */
tsp_sel1_int_entry_panic:
bl plat_panic_handler
no_ret plat_panic_handler
endfunc tsp_sel1_intr_entry
/*---------------------------------------------
......@@ -409,7 +409,7 @@ func tsp_cpu_resume_entry
restore_args_call_smc
/* Should never reach here */
bl plat_panic_handler
no_ret plat_panic_handler
endfunc tsp_cpu_resume_entry
/*---------------------------------------------
......@@ -422,7 +422,7 @@ func tsp_fast_smc_entry
restore_args_call_smc
/* Should never reach here */
bl plat_panic_handler
no_ret plat_panic_handler
endfunc tsp_fast_smc_entry
/*---------------------------------------------
......@@ -439,5 +439,5 @@ func tsp_std_smc_entry
restore_args_call_smc
/* Should never reach here */
bl plat_panic_handler
no_ret plat_panic_handler
endfunc tsp_std_smc_entry
bl32/tsp/aarch64/tsp_exceptions.S
View file @ a806dad5
......@@ -105,19 +105,19 @@ vector_base tsp_exceptions
* -----------------------------------------------------
*/
vector_entry sync_exception_sp_el0
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size sync_exception_sp_el0
vector_entry irq_sp_el0
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size irq_sp_el0
vector_entry fiq_sp_el0
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size fiq_sp_el0
vector_entry serror_sp_el0
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size serror_sp_el0
......@@ -127,7 +127,7 @@ vector_entry serror_sp_el0
* -----------------------------------------------------
*/
vector_entry sync_exception_sp_elx
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size sync_exception_sp_elx
vector_entry irq_sp_elx
......@@ -139,7 +139,7 @@ vector_entry fiq_sp_elx
check_vector_size fiq_sp_elx
vector_entry serror_sp_elx
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size serror_sp_elx
......@@ -149,19 +149,19 @@ vector_entry serror_sp_elx
* -----------------------------------------------------
*/
vector_entry sync_exception_aarch64
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size sync_exception_aarch64
vector_entry irq_aarch64
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size irq_aarch64
vector_entry fiq_aarch64
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size fiq_aarch64
vector_entry serror_aarch64
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size serror_aarch64
......@@ -171,17 +171,17 @@ vector_entry serror_aarch64
* -----------------------------------------------------
*/
vector_entry sync_exception_aarch32
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size sync_exception_aarch32
vector_entry irq_aarch32
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size irq_aarch32
vector_entry fiq_aarch32
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size fiq_aarch32
vector_entry serror_aarch32
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size serror_aarch32
common/aarch32/debug.S
View file @ a806dad5
......@@ -38,7 +38,7 @@
* The common implementation of do_panic for all BL stages
***********************************************************/
func do_panic
b plat_panic_handler
no_ret plat_panic_handler
endfunc do_panic
/***********************************************************
......@@ -50,5 +50,5 @@ func report_exception
mrs r0, cpsr
and r0, #MODE32_MASK
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
endfunc report_exception
common/aarch64/debug.S
View file @ a806dad5
......@@ -191,5 +191,5 @@ _panic_handler:
/* Pass to plat_panic_handler the address from where el3_panic was
* called, not the address of the call from el3_panic. */
mov x30,x6
b plat_panic_handler
no_ret plat_panic_handler
endfunc do_panic
common/aarch64/early_exceptions.S
View file @ a806dad5
......@@ -47,25 +47,25 @@ vector_base early_exceptions
vector_entry SynchronousExceptionSP0
mov x0, #SYNC_EXCEPTION_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionSP0
vector_entry IrqSP0
mov x0, #IRQ_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqSP0
vector_entry FiqSP0
mov x0, #FIQ_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqSP0
vector_entry SErrorSP0
mov x0, #SERROR_SP_EL0
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorSP0
/* -----------------------------------------------------
......@@ -75,25 +75,25 @@ vector_entry SErrorSP0
vector_entry SynchronousExceptionSPx
mov x0, #SYNC_EXCEPTION_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionSPx
vector_entry IrqSPx
mov x0, #IRQ_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqSPx
vector_entry FiqSPx
mov x0, #FIQ_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqSPx
vector_entry SErrorSPx
mov x0, #SERROR_SP_ELX
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorSPx
/* -----------------------------------------------------
......@@ -103,25 +103,25 @@ vector_entry SErrorSPx
vector_entry SynchronousExceptionA64
mov x0, #SYNC_EXCEPTION_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionA64
vector_entry IrqA64
mov x0, #IRQ_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqA64
vector_entry FiqA64
mov x0, #FIQ_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqA64
vector_entry SErrorA64
mov x0, #SERROR_AARCH64
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorA64
/* -----------------------------------------------------
......@@ -131,23 +131,23 @@ vector_entry SErrorA64
vector_entry SynchronousExceptionA32
mov x0, #SYNC_EXCEPTION_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SynchronousExceptionA32
vector_entry IrqA32
mov x0, #IRQ_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size IrqA32
vector_entry FiqA32
mov x0, #FIQ_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size FiqA32
vector_entry SErrorA32
mov x0, #SERROR_AARCH32
bl plat_report_exception
bl plat_panic_handler
no_ret plat_panic_handler
check_vector_size SErrorA32
include/common/aarch32/asm_macros.S
View file @ a806dad5
......@@ -102,4 +102,26 @@
ldr r0, =(\_name + \_size)
.endm
/*
* Macro to mark instances where we're jumping to a function and don't
* expect a return. To provide the function being jumped to with
* additional information, we use 'bl' instruction to jump rather than
* 'b'.
*
* Debuggers infer the location of a call from where LR points to, which
* is usually the instruction after 'bl'. If this macro expansion
* happens to be the last location in a function, that'll cause the LR
* to point a location beyond the function, thereby misleading debugger
* back trace. We therefore insert a 'nop' after the function call for
* debug builds, unless 'skip_nop' parameter is non-zero.
*/
.macro no_ret _func:req, skip_nop=0
bl \_func
#if DEBUG
.ifeq \skip_nop
nop
.endif
#endif
.endm
#endif /* __ASM_MACROS_S__ */
include/common/aarch32/el3_common_macros.S
View file @ a806dad5
......@@ -212,7 +212,7 @@
/* This is a cold boot on a secondary CPU */
bl plat_secondary_cold_boot_setup
/* plat_secondary_cold_boot_setup() is not supposed to return */
bl plat_panic_handler
no_ret plat_panic_handler
do_primary_cold_boot:
.endif /* _secondary_cold_boot */
......
include/common/aarch64/asm_macros.S
View file @ a806dad5
......@@ -178,4 +178,26 @@
.endif
.endm
/*
* Macro to mark instances where we're jumping to a function and don't
* expect a return. To provide the function being jumped to with
* additional information, we use 'bl' instruction to jump rather than
* 'b'.
*
* Debuggers infer the location of a call from where LR points to, which
* is usually the instruction after 'bl'. If this macro expansion
* happens to be the last location in a function, that'll cause the LR
* to point a location beyond the function, thereby misleading debugger
* back trace. We therefore insert a 'nop' after the function call for
* debug builds, unless 'skip_nop' parameter is non-zero.
*/
.macro no_ret _func:req, skip_nop=0
bl \_func
#if DEBUG
.ifeq \skip_nop
nop
.endif
#endif
.endm
#endif /* __ASM_MACROS_S__ */
lib/psci/aarch32/psci_helpers.S
View file @ a806dad5
......@@ -176,5 +176,5 @@ endfunc do_stack_maintenance
func psci_power_down_wfi
dsb sy // ensure write buffer empty
wfi
bl plat_panic_handler
no_ret plat_panic_handler
endfunc psci_power_down_wfi
lib/psci/aarch64/psci_helpers.S
View file @ a806dad5
......@@ -167,7 +167,7 @@ endfunc psci_do_pwrup_cache_maintenance
func psci_power_down_wfi
dsb sy // ensure write buffer empty
wfi
bl plat_panic_handler
no_ret plat_panic_handler
endfunc psci_power_down_wfi
/* -----------------------------------------------------------------------
......
plat/arm/board/fvp/aarch64/fvp_helpers.S
View file @ a806dad5
......@@ -111,7 +111,7 @@ secondary_cold_boot_wait:
*/
dsb sy
wfi
bl plat_panic_handler
no_ret plat_panic_handler
#else
mov_imm x0, PLAT_ARM_TRUSTED_MAILBOX_BASE
......@@ -182,7 +182,7 @@ warm_reset:
* ---------------------------------------------------------------------
*/
_panic_handler:
bl plat_panic_handler
no_ret plat_panic_handler
endfunc plat_get_my_entrypoint
/* -----------------------------------------------------
......
plat/arm/board/juno/aarch64/juno_helpers.S
View file @ a806dad5
......@@ -201,7 +201,7 @@ func plat_reset_handler
JUMP_TO_HANDLER_IF_JUNO_R(2)
/* Board revision is not supported */
bl plat_panic_handler
no_ret plat_panic_handler
endfunc plat_reset_handler
......
plat/xilinx/zynqmp/aarch64/zynqmp_helpers.S
View file @ a806dad5
......@@ -61,7 +61,7 @@ func plat_secondary_cold_boot_setup
*/
dsb sy
1:
bl plat_panic_handler
no_ret plat_panic_handler
endfunc plat_secondary_cold_boot_setup
func plat_is_my_cpu_primary
......
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