kern: add hardware single step extension

This commit is contained in:
Michael Scire 2021-07-27 05:34:40 -07:00 committed by SciresM
parent 904ab19823
commit 4075d24e0c
10 changed files with 226 additions and 4 deletions

View file

@ -15,6 +15,39 @@
*/
#include <mesosphere/kern_select_assembly_offsets.h>
#if defined(MESOSPHERE_ENABLE_HARDWARE_SINGLE_STEP)
.macro disable_single_step, scratch
/* Clear MDSCR_EL1.SS. */
mrs \scratch, mdscr_el1
bic \scratch, \scratch, #1
msr mdscr_el1, \scratch
.endm
.macro check_enable_single_step, scratch1, scratch2, spsr_value
/* Check if single-step is requested. */
ldrb \scratch1, [sp, #(EXCEPTION_CONTEXT_SIZE + THREAD_STACK_PARAMETERS_IS_SINGLE_STEP)]
tbz \scratch1, #0, .skip_single_step\@
/* If single-step is requested, enable the single-step machine by setting MDSCR_EL1.SS. */
mrs \scratch2, mdscr_el1
orr \scratch2, \scratch2, #1
msr mdscr_el1, \scratch2
/* Since we're returning from an exception, set SPSR.SS so we actually advance an instruction. */
orr \spsr_value, \spsr_value, #(1 << 21)
isb
.skip_single_step\@:
.endm
#else
.macro disable_single_step, scratch
.endm
.macro check_enable_single_step, scratch1, scratch2, spsr_value
.endm
#endif
/* ams::kern::svc::CallReturnFromException64(Result result) */
.section .text._ZN3ams4kern3svc25CallReturnFromException64Ev, "ax", %progbits
.global _ZN3ams4kern3svc25CallReturnFromException64Ev
@ -89,6 +122,9 @@ _ZN3ams4kern3svc14RestoreContextEm:
ldp x30, x8, [sp, #(EXCEPTION_CONTEXT_X30_SP)]
ldp x9, x10, [sp, #(EXCEPTION_CONTEXT_PC_PSR)]
ldr x11, [sp, #(EXCEPTION_CONTEXT_TPIDR)]
check_enable_single_step w0, x0, x10
msr sp_el0, x8
msr elr_el1, x9
msr spsr_el1, x10

View file

@ -16,6 +16,39 @@
#include <mesosphere/kern_build_config.hpp>
#include <mesosphere/kern_select_assembly_offsets.h>
#if defined(MESOSPHERE_ENABLE_HARDWARE_SINGLE_STEP)
.macro disable_single_step, scratch
/* Clear MDSCR_EL1.SS. */
mrs \scratch, mdscr_el1
bic \scratch, \scratch, #1
msr mdscr_el1, \scratch
.endm
.macro check_enable_single_step, scratch1, scratch2, spsr_value
/* Check if single-step is requested. */
ldrb \scratch1, [sp, #(EXCEPTION_CONTEXT_SIZE + THREAD_STACK_PARAMETERS_IS_SINGLE_STEP)]
tbz \scratch1, #0, .skip_single_step\@
/* If single-step is requested, enable the single-step machine by setting MDSCR_EL1.SS. */
mrs \scratch2, mdscr_el1
orr \scratch2, \scratch2, #1
msr mdscr_el1, \scratch2
/* Since we're returning from an SVC, make sure SPSR.SS is cleared so we break instantly on the instruction after the SVC. */
bic \spsr_value, \spsr_value, #(1 << 21)
isb
.skip_single_step\@:
.endm
#else
.macro disable_single_step, scratch
.endm
.macro check_enable_single_step, scratch1, scratch2, spsr_value
.endm
#endif
/* ams::kern::arch::arm64::SvcHandler64() */
.section .text._ZN3ams4kern4arch5arm6412SvcHandler64Ev, "ax", %progbits
.global _ZN3ams4kern4arch5arm6412SvcHandler64Ev
@ -51,6 +84,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler64Ev:
stp x8, x9, [sp, #(EXCEPTION_CONTEXT_SP_PC)]
stp x10, x11, [sp, #(EXCEPTION_CONTEXT_PSR_TPIDR)]
/* Disable single-step. */
disable_single_step x8
/* Check if the SVC index is out of range. */
mrs x8, esr_el1
and x8, x8, #0xFF
@ -154,6 +190,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler64Ev:
ldp x30, x8, [sp, #(EXCEPTION_CONTEXT_X30_SP)]
ldp x9, x10, [sp, #(EXCEPTION_CONTEXT_PC_PSR)]
ldr x11, [sp, #(EXCEPTION_CONTEXT_TPIDR)]
check_enable_single_step w0, x0, x10
msr sp_el0, x8
msr elr_el1, x9
msr spsr_el1, x10
@ -203,6 +242,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler64Ev:
ldp x9, x10, [sp, #(EXCEPTION_CONTEXT_PC_PSR)]
ldr x11, [sp, #(EXCEPTION_CONTEXT_TPIDR)]
ldr x18, [sp, #(EXCEPTION_CONTEXT_X18)]
check_enable_single_step w12, x12, x10
msr sp_el0, x8
msr elr_el1, x9
msr spsr_el1, x10
@ -260,6 +302,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler32Ev:
stp x12, x13, [sp, #(EXCEPTION_CONTEXT_X12_X13)]
stp x14, xzr, [sp, #(EXCEPTION_CONTEXT_X14_X15)]
/* Disable single-step. */
disable_single_step x8
/* Check if the SVC index is out of range. */
mrs x16, esr_el1
and x16, x16, #0xFF
@ -359,6 +404,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler32Ev:
/* Restore registers. */
ldp x17, x20, [sp, #(EXCEPTION_CONTEXT_PC_PSR)]
ldr x19, [sp, #(EXCEPTION_CONTEXT_TPIDR)]
check_enable_single_step w0, x0, x20
msr elr_el1, x17
msr spsr_el1, x20
msr tpidr_el0, x19
@ -402,6 +450,9 @@ _ZN3ams4kern4arch5arm6412SvcHandler32Ev:
ldp x14, xzr, [sp, #(EXCEPTION_CONTEXT_X14_X15)]
ldp x17, x20, [sp, #(EXCEPTION_CONTEXT_PC_PSR)]
ldr x19, [sp, #(EXCEPTION_CONTEXT_TPIDR)]
check_enable_single_step w21, x21, x20
msr elr_el1, x17
msr spsr_el1, x20
msr tpidr_el0, x19