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Rewrite arm/stack_machdep.c for EABI; add stack(9) support to arm kernels.

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The old stack_machdep.c code was written for the APCS ABI (aka "oldabi").
When we switched to ARM EABI (back in freebsd 10) this file never got
updated, and apparently nobody noticed that until now.

The new implementation uses the same stack unwinder code used by the
arm implemenation of the db_trace stuff.
This commit is contained in:
ian 2019-11-14 16:46:27 +00:00
parent 8eade0cb10
commit b005478a94
3 changed files with 42 additions and 40 deletions
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80
sys/arm/arm/stack_machdep.c
View File

@ -1,8 +1,7 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2005 Antoine Brodin
* All rights reserved.
* Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -29,63 +28,64 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/stack.h>
#include <machine/vmparam.h>
#include <machine/pcb.h>
#include <machine/stack.h>
/*
* This code makes assumptions about the stack layout. These are correct
* when using APCS (the old ABI), but are no longer true with AAPCS and the
* ARM EABI. There is also an issue with clang and llvm when building for
* APCS where it lays out the stack incorrectly. Because of this we disable
* this when building for ARM EABI or when building with clang.
*/
extern vm_offset_t kernel_vm_end;
static void
stack_capture(struct stack *st, u_int32_t *frame)
stack_capture(struct stack *st, struct unwind_state *state)
{
stack_zero(st);
while (unwind_stack_one(state, 1) == 0) {
if (stack_put(st, state->registers[PC]) == -1)
break;
}
}
void
stack_save(struct stack *st)
{
struct unwind_state state;
uint32_t sp;
/* Read the stack pointer */
__asm __volatile("mov %0, sp" : "=&r" (sp));
state.registers[FP] = (uint32_t)__builtin_frame_address(0);
state.registers[SP] = sp;
state.registers[LR] = (uint32_t)__builtin_return_address(0);
state.registers[PC] = (uint32_t)stack_save;
stack_capture(st, &state);
}
void
stack_save_td(struct stack *st, struct thread *td)
{
u_int32_t *frame;
struct unwind_state state;
if (TD_IS_SWAPPED(td))
panic("stack_save_td: swapped");
if (TD_IS_RUNNING(td))
panic("stack_save_td: running");
KASSERT(!TD_IS_SWAPPED(td), ("stack_save_td: swapped"));
KASSERT(!TD_IS_RUNNING(td), ("stack_save_td: running"));
/*
* This register, the frame pointer, is incorrect for the ARM EABI
* as it doesn't have a frame pointer, however it's value is not used
* when building for EABI.
*/
frame = (u_int32_t *)td->td_pcb->pcb_regs.sf_r11;
stack_zero(st);
stack_capture(st, frame);
state.registers[FP] = td->td_pcb->pcb_regs.sf_r11;
state.registers[SP] = td->td_pcb->pcb_regs.sf_sp;
state.registers[LR] = td->td_pcb->pcb_regs.sf_lr;
state.registers[PC] = td->td_pcb->pcb_regs.sf_pc;
stack_capture(st, &state);
}
int
stack_save_td_running(struct stack *st, struct thread *td)
{
if (td == curthread) {
stack_save(st);
return (0);
}
return (EOPNOTSUPP);
}
void
stack_save(struct stack *st)
{
u_int32_t *frame;
frame = (u_int32_t *)__builtin_frame_address(0);
stack_zero(st);
stack_capture(st, frame);
}

1
sys/arm/conf/std.armv6
View File

@ -34,6 +34,7 @@ options GEOM_LABEL # Provides labelization
options COMPAT_43 # Compatible with BSD 4.3 [KEEP THIS!]
options SCSI_DELAY=5000 # Delay (in ms) before probing SCSI
options KTRACE # ktrace(1) support
options STACK # stack(9) support
options SYSVSHM # SYSV-style shared memory
options SYSVMSG # SYSV-style message queues
options SYSVSEM # SYSV-style semaphores

1
sys/arm/conf/std.armv7
View File

@ -34,6 +34,7 @@ options GEOM_LABEL # Provides labelization
options COMPAT_43 # Compatible with BSD 4.3 [KEEP THIS!]
options SCSI_DELAY=5000 # Delay (in ms) before probing SCSI
options KTRACE # ktrace(1) support
options STACK # stack(9) support
options SYSVSHM # SYSV-style shared memory
options SYSVMSG # SYSV-style message queues
options SYSVSEM # SYSV-style semaphores