.align 2
.globl EXT(fleh_undef)
-LEXT(fleh_undef)
- mrs sp, spsr // Check the previous mode
+/*
+ * Ensures the stack is safely aligned, usually in preparation for an external branch
+ * arg0: temp register for storing the stack offset
+ * arg1: temp register for storing the previous stack pointer
+ */
+.macro ALIGN_STACK
+/*
+ * For armv7k ABI, the stack needs to be 16-byte aligned
+ */
+#if __BIGGEST_ALIGNMENT__ > 4
+ and $0, sp, #0x0F // sp mod 16-bytes
+ cmp $0, #4 // need space for the sp on the stack
+ addlt $0, $0, #0x10 // make room if needed, but keep stack aligned
+ mov $1, sp // get current sp
+ sub sp, sp, $0 // align stack
+ str $1, [sp] // store previous sp on stack
+#endif
+.endmacro
+
+/*
+ * Restores the stack pointer to its previous value following an ALIGN_STACK call
+ */
+.macro UNALIGN_STACK
+#if __BIGGEST_ALIGNMENT__ > 4
+ ldr sp, [sp]
+#endif
+.endmacro
+
+/*
+ * Checks that cpu is currently in the expected mode, panics if not.
+ * arg0: the expected mode, should be one of the PSR_*_MODE defines
+ */
+.macro VERIFY_EXCEPTION_MODE
+ mrs sp, cpsr // Read cpsr
+ and sp, sp, #PSR_MODE_MASK // Extract current mode
+ cmp sp, $0 // Check specified mode
+ movne r0, sp
+ bne EXT(ExceptionVectorPanic)
+.endmacro
+
+/*
+ * Checks previous processor mode. If usermode, will execute the code
+ * following the macro to handle the userspace exception. Otherwise,
+ * will branch to a ELSE_IF_KERNELMODE_EXCEPTION call with the same
+ * argument.
+ * arg0: arbitrary string indicating the exception class, e.g. 'dataabt'
+ */
+.macro IF_USERMODE_EXCEPTION
+ mrs sp, spsr
+ and sp, sp, #PSR_MODE_MASK // Is it from user?
+ cmp sp, #PSR_USER_MODE
+ beq $0_from_user
+ cmp sp, #PSR_IRQ_MODE
+ beq $0_from_irq
+ cmp sp, #PSR_FIQ_MODE
+ beq $0_from_fiq
+ bne $0_from_svc
+$0_from_user:
+.endmacro
+
+/*
+ * Handles an exception taken from kernelmode (IRQ/FIQ/SVC/etc).
+ * Places the processor into the correct mode and executes the
+ * code following the macro to handle the kernel exception.
+ * Intended to be paired with a prior call to IF_USERMODE_EXCEPTION.
+ * arg0: arbitrary string indicating the exception class, e.g. 'dataabt'
+ */
+.macro ELSE_IF_KERNELMODE_EXCEPTION
+$0_from_irq:
+ cpsid i, #PSR_IRQ_MODE
+ b $0_from_kernel
+$0_from_fiq:
+ cpsid i, #PSR_FIQ_MODE
+ b $0_from_kernel
+$0_from_svc:
+ cpsid i, #PSR_SVC_MODE
+$0_from_kernel:
+.endmacro
+
+LEXT(fleh_undef)
+VERIFY_EXCEPTION_MODE PSR_UND_MODE
+ mrs sp, spsr // For check the previous mode
tst sp, #PSR_TF // Is it Thumb?
subeq lr, lr, #4
subne lr, lr, #2
- tst sp, #0x0f // Is it from user?
- bne undef_from_kernel
-
-undef_from_user:
+IF_USERMODE_EXCEPTION undef
mrc p15, 0, sp, c13, c0, 4 // Read TPIDRPRW
add sp, sp, ACT_PCBDATA // Get current thread PCB pointer
stmia sp, {r0-r12, sp, lr}^ // Save user context on PCB
mov r7, #0 // Zero the frame pointer
nop
-
+
mov r0, sp // Store arm_saved_state pointer
// for argument
mrs r4, spsr
str r4, [sp, SS_CPSR] // Save user mode cpsr
- mrs r4, cpsr // Read cpsr
cpsid i, #PSR_SVC_MODE
mrs r3, cpsr // Read cpsr
msr spsr_cxsf, r3 // Set spsr(svc mode cpsr)
mcr p15, 0, r3, c13, c0, 1 // Set CONTEXTIDR
isb
#endif
- and r0, r4, #PSR_MODE_MASK // Extract current mode
- cmp r0, #PSR_UND_MODE // Check undef mode
- bne EXT(ExceptionVectorPanic)
mvn r0, #0
str r0, [r9, TH_IOTIER_OVERRIDE] // Reset IO tier override to -1 before handling abort from userspace
// sleh will enable interrupt
b load_and_go_user
-undef_from_kernel:
- mrs sp, cpsr // Read cpsr
- and sp, sp, #PSR_MODE_MASK // Extract current mode
- cmp sp, #PSR_UND_MODE // Check undef mode
- movne r0, sp
- bne EXT(ExceptionVectorPanic)
- mrs sp, spsr // Check the previous mode
-
+ELSE_IF_KERNELMODE_EXCEPTION undef
/*
* We have a kernel stack already, and I will use it to save contexts
* IRQ is disabled
*/
-
-#if CONFIG_DTRACE
- /*
- * See if we came here from IRQ or SVC mode, and go back to that mode
- */
-
- and sp, sp, #PSR_MODE_MASK
- cmp sp, #PSR_IRQ_MODE
- bne undef_from_kernel_svc
-
- cpsid i, #PSR_IRQ_MODE
- b handle_undef
-#endif
-
-undef_from_kernel_svc:
- cpsid i, #PSR_SVC_MODE
-
-handle_undef:
#if CONFIG_DTRACE
// We need a frame for backtracing. The LR here is the LR of supervisor mode, not the location where the exception
// took place. We'll store that later after we switch to undef mode and pull out the LR from there.
#if CONFIG_DTRACE
add r7, sp, EXC_CTX_SIZE // Save frame pointer
#endif
-
- mov ip, sp // Stack transfer
-
- cpsid i, #PSR_UND_MODE
-
- str lr, [ip, SS_PC] // Save complete
- mrs r4, spsr
- str r4, [ip, SS_CPSR]
-
-#if CONFIG_DTRACE
- /*
- * Go back to previous mode for mode specific regs
- */
- and r4, r4, #PSR_MODE_MASK
- cmp r4, #PSR_IRQ_MODE
- bne handle_undef_from_svc
-
- cpsid i, #PSR_IRQ_MODE
- b handle_undef2
-#endif
-handle_undef_from_svc:
- cpsid i, #PSR_SVC_MODE
+ mrs r4, lr_und
+ str r4, [sp, SS_PC] // Save complete
+ mrs r4, spsr_und
+ str r4, [sp, SS_CPSR]
-handle_undef2:
+ mov ip, sp
/*
sp - stack pointer
#endif
mov r0, sp // Argument
-/*
- * For armv7k ABI, the stack needs to be 16-byte aligned
- */
-#if __BIGGEST_ALIGNMENT__ > 4
- and r1, sp, #0x0F // sp mod 16-bytes
- cmp r1, #4 // need space for the sp on the stack
- addlt r1, r1, #0x10 // make room if needed, but keep stack aligned
- mov r2, sp // get current sp
- sub sp, sp, r1 // align stack
- str r2, [sp] // store previous sp on stack
-#endif
-
+ ALIGN_STACK r2, r3
bl EXT(sleh_undef) // Call second level handler
-
-#if __BIGGEST_ALIGNMENT__ > 4
- ldr sp, [sp] // restore stack
-#endif
+ UNALIGN_STACK
#if __ARM_USER_PROTECT__
mrc p15, 0, r9, c13, c0, 4 // Read TPIDRPRW
str r0, [sp, SS_SP] // Save supervisor mode sp
str lr, [sp, SS_LR] // Save supervisor mode lr
+ ALIGN_STACK r0, r1
adr r0, L_kernel_swi_panic_str // Load panic messages and panic()
blx EXT(panic)
b .
mov r1, sp
str r2, [sp]
str r3, [sp, #4]
+ ALIGN_STACK r2, r3
mov r2, #2
bl EXT(exception_triage)
b .
.globl EXT(fleh_prefabt)
LEXT(fleh_prefabt)
+VERIFY_EXCEPTION_MODE PSR_ABT_MODE
sub lr, lr, #4
-
- mrs sp, spsr // For check the previous mode
- tst sp, #0x0f // Is it from user?
- bne prefabt_from_kernel
-prefabt_from_user:
+IF_USERMODE_EXCEPTION prefabt
mrc p15, 0, sp, c13, c0, 4 // Read TPIDRPRW
add sp, sp, ACT_PCBDATA // Get User PCB
mrs r4, spsr
str r4, [sp, SS_CPSR] // Save user mode cpsr
- mrs r4, cpsr // Read cpsr
cpsid i, #PSR_SVC_MODE
mrs r3, cpsr // Read cpsr
msr spsr_cxsf, r3 // Set spsr(svc mode cpsr)
mcr p15, 0, r3, c13, c0, 1 // Set CONTEXTIDR
isb
#endif
- and r0, r4, #PSR_MODE_MASK // Extract current mode
- cmp r0, #PSR_ABT_MODE // Check abort mode
- bne EXT(ExceptionVectorPanic)
mvn r0, #0
str r0, [r9, TH_IOTIER_OVERRIDE] // Reset IO tier override to -1 before handling abort from userspace
// Sleh will enable interrupt
b load_and_go_user
-prefabt_from_kernel:
- mrs sp, cpsr // Read cpsr
- and sp, sp, #PSR_MODE_MASK // Extract current mode
- cmp sp, #PSR_ABT_MODE // Check abort mode
- movne r0, sp
- bne EXT(ExceptionVectorPanic)
- mrs sp, spsr // Check the previous mode
-
+ELSE_IF_KERNELMODE_EXCEPTION prefabt
/*
* We have a kernel stack already, and I will use it to save contexts:
* ------------------
*
* IRQ is disabled
*/
- cpsid i, #PSR_SVC_MODE
-
sub sp, sp, EXC_CTX_SIZE
stmia sp, {r0-r12}
add r0, sp, EXC_CTX_SIZE
mcr p15, 0, r3, c13, c0, 1 // Set CONTEXTIDR
isb
#endif
- mov ip, sp
- cpsid i, #PSR_ABT_MODE
-
- str lr, [ip, SS_PC] // Save pc to pc and
+ mrs r4, lr_abt
+ str r4, [sp, SS_PC] // Save pc
mrc p15, 0, r5, c6, c0, 2 // Read IFAR
- str r5, [ip, SS_VADDR] // and fault address of pcb
+ str r5, [sp, SS_VADDR] // and fault address of pcb
mrc p15, 0, r5, c5, c0, 1 // Read (instruction) Fault Status
- str r5, [ip, SS_STATUS] // Save fault status register to pcb
-
- mrs r4, spsr
- str r4, [ip, SS_CPSR]
-
- cpsid i, #PSR_SVC_MODE
+ str r5, [sp, SS_STATUS] // Save fault status register to pcb
- mov r0, sp
-
-/*
- * For armv7k ABI, the stack needs to be 16-byte aligned
- */
-#if __BIGGEST_ALIGNMENT__ > 4
- and r1, sp, #0x0F // sp mod 16-bytes
- cmp r1, #4 // need space for the sp on the stack
- addlt r1, r1, #0x10 // make room if needed, but keep stack aligned
- mov r2, sp // get current sp
- sub sp, sp, r1 // align stack
- str r2, [sp] // store previous sp on stack
-#endif
+ mrs r4, spsr_abt
+ str r4, [sp, SS_CPSR]
+ mov r0, sp
+ ALIGN_STACK r1, r2
mov r1, T_PREFETCH_ABT // Pass abort type
bl EXT(sleh_abort) // Call second level handler
-
-#if __BIGGEST_ALIGNMENT__ > 4
- ldr sp, [sp] // restore stack
-#endif
+ UNALIGN_STACK
mrc p15, 0, r9, c13, c0, 4 // Read TPIDRPRW
#if __ARM_USER_PROTECT__
.globl EXT(fleh_dataabt)
LEXT(fleh_dataabt)
+VERIFY_EXCEPTION_MODE PSR_ABT_MODE
sub lr, lr, #8
-
- mrs sp, spsr // For check the previous mode
- tst sp, #0x0f // Is it from kernel?
- bne dataabt_from_kernel
-
-dataabt_from_user:
+IF_USERMODE_EXCEPTION dataabt
mrc p15, 0, sp, c13, c0, 4 // Read TPIDRPRW
add sp, sp, ACT_PCBDATA // Get User PCB
str r5, [sp, SS_STATUS] // Save fault status register to pcb
str r6, [sp, SS_VADDR] // Save fault address to pcb
- mrs r4, cpsr // Read cpsr
cpsid i, #PSR_SVC_MODE
mrs r3, cpsr // Read cpsr
msr spsr_cxsf, r3 // Set spsr(svc mode cpsr)
mcr p15, 0, r3, c13, c0, 1 // Set CONTEXTIDR
isb
#endif
- and r0, r4, #PSR_MODE_MASK // Extract current mode
- cmp r0, #PSR_ABT_MODE // Check abort mode
- bne EXT(ExceptionVectorPanic)
mvn r0, #0
str r0, [r9, TH_IOTIER_OVERRIDE] // Reset IO tier override to -1 before handling abort from userspace
// Sleh will enable irq
b load_and_go_user
-dataabt_from_kernel:
- mrs sp, cpsr // Read cpsr
- and sp, sp, #PSR_MODE_MASK // Extract current mode
- cmp sp, #PSR_ABT_MODE // Check abort mode
- movne r0, sp
- bne EXT(ExceptionVectorPanic)
- mrs sp, spsr // Check the previous mode
-
+ELSE_IF_KERNELMODE_EXCEPTION dataabt
/*
* We have a kernel stack already, and I will use it to save contexts:
* ------------------
*
* IRQ is disabled
*/
- cpsid i, #PSR_SVC_MODE
-
sub sp, sp, EXC_CTX_SIZE
stmia sp, {r0-r12}
add r0, sp, EXC_CTX_SIZE
fmxr fpscr, r4 // And shove it into FPSCR
#endif
- mov ip, sp
-
- cpsid i, #PSR_ABT_MODE
-
- str lr, [ip, SS_PC]
- mrs r4, spsr
- str r4, [ip, SS_CPSR]
-
- cpsid i, #PSR_SVC_MODE
+ mrs r4, lr_abt
+ str r4, [sp, SS_PC]
+ mrs r4, spsr_abt
+ str r4, [sp, SS_CPSR]
#if __ARM_USER_PROTECT__
mrc p15, 0, r10, c2, c0, 0 // Get TTBR0
str r6, [sp, SS_VADDR] // Save fault address to pcb
mov r0, sp // Argument
-
-/*
- * For armv7k ABI, the stack needs to be 16-byte aligned
- */
-#if __BIGGEST_ALIGNMENT__ > 4
- and r1, sp, #0x0F // sp mod 16-bytes
- cmp r1, #4 // need space for the sp on the stack
- addlt r1, r1, #0x10 // make room if needed, but keep stack aligned
- mov r2, sp // get current sp
- sub sp, sp, r1 // align stack
- str r2, [sp] // store previous sp on stack
-#endif
-
+ ALIGN_STACK r1, r2
mov r1, T_DATA_ABT // Pass abort type
bl EXT(sleh_abort) // Call second level handler
-
-#if __BIGGEST_ALIGNMENT__ > 4
- ldr sp, [sp] // restore stack (removed align padding)
-#endif
+ UNALIGN_STACK
mrc p15, 0, r9, c13, c0, 4 // Read TPIDRPRW
#if __ARM_USER_PROTECT__
ldr lr, [sp, SS_LR] // Restore the link register
stmfd sp!, {r7, lr} // Push a fake frame
- /* TODO: Should this be setting r7? I think so. */
- mov r7, sp // Set the frame pointer
-
-#if __BIGGEST_ALIGNMENT__ > 4
- and r2, sp, #0x0F // sp mod 16-bytes
- cmp r2, #4 // need space for the sp on the stack
- addlt r2, r2, #0x10 // make room if needed, but keep stack aligned
- mov r3, sp // get current sp
- sub sp, sp, r2 // align stack
- str r3, [sp] // store previous sp on stack
-#endif
-
+ ALIGN_STACK r2, r3
bl EXT(ast_taken_kernel) // Handle AST_URGENT
-
-#if __BIGGEST_ALIGNMENT__ > 4
- ldr sp, [sp]
-#endif
-
+ UNALIGN_STACK
ldmfd sp!, {r7, lr} // Pop the fake frame
mrc p15, 0, r9, c13, c0, 4 // Reload r9 from TPIDRPRW
mcr p15, 0, r3, c13, c0, 1 // Set CONTEXTIDR
isb
#endif
+
+ ALIGN_STACK r0, r1
mov r0, r8 // Get current cpu in arg 0
mov r1, SIGPdec // Decrementer signal in arg1
mov r2, #0
mov r3, #0
bl EXT(cpu_signal) // Call cpu_signal
+ UNALIGN_STACK
mrc p15, 0, r9, c13, c0, 4 // Read TPIDRPRW
cpsid i, #PSR_IRQ_MODE
cpsie f
mov sp, r6 // Restore the stack pointer
+ ALIGN_STACK r2, r3
msr spsr_cxsf, r4 // Restore the spsr
ldr r2, [r9, ACT_PREEMPT_CNT] // Load preemption count
add r2, r2, #1 // Increment count
movs r4, r4
COND_EXTERN_BLNE(interrupt_trace_exit)
#endif
+ UNALIGN_STACK
mrc p15, 0, r9, c13, c0, 4 // Reload r9 from TPIDRPRW
cmp r5, #0 // Test if ASTs pending
beq return_to_user_now // Branch if no ASTs
-#if __BIGGEST_ALIGNMENT__ > 4
- and r2, sp, #0x0F // sp mod 16-bytes
- cmp r2, #4 // need space for the sp on the stack
- addlt r2, r2, #0x10 // make room if needed, but keep stack aligned
- mov r3, sp // get current sp
- sub sp, sp, r2 // align stack
- str r3, [sp] // store previous sp on stack
-#endif
-
bl EXT(ast_taken_user) // Handle all ASTs (may continue via thread_exception_return)
-#if __BIGGEST_ALIGNMENT__ > 4
- ldr sp, [sp] // Restore the stack pointer
-#endif
-
mrc p15, 0, r9, c13, c0, 4 // Reload r9 from TPIDRPRW
b load_and_go_user // Loop back
LEXT(ExceptionVectorPanic)
cpsid i, #PSR_SVC_MODE
+ ALIGN_STACK r1, r2
mov r1, r0
adr r0, L_evimpanic_str
blx EXT(panic)
projects / apple / xnu.git / blobdiff