linux/arch/riscv/kernel/Makefile
Changbin Du 22e2100b1b
riscv: fix oops caused by irqsoff latency tracer
The trace_hardirqs_{on,off}() require the caller to setup frame pointer
properly. This because these two functions use macro 'CALLER_ADDR1' (aka.
__builtin_return_address(1)) to acquire caller info. If the $fp is used
for other purpose, the code generated this macro (as below) could trigger
memory access fault.

   0xffffffff8011510e <+80>:    ld      a1,-16(s0)
   0xffffffff80115112 <+84>:    ld      s2,-8(a1)  # <-- paging fault here

The oops message during booting if compiled with 'irqoff' tracer enabled:
[    0.039615][    T0] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8
[    0.041925][    T0] Oops [#1]
[    0.042063][    T0] Modules linked in:
[    0.042864][    T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-rc1-00233-g9a20c48d1ed2 #29
[    0.043568][    T0] Hardware name: riscv-virtio,qemu (DT)
[    0.044343][    T0] epc : trace_hardirqs_on+0x56/0xe2
[    0.044601][    T0]  ra : restore_all+0x12/0x6e
[    0.044721][    T0] epc : ffffffff80126a5c ra : ffffffff80003b94 sp : ffffffff81403db0
[    0.044801][    T0]  gp : ffffffff8163acd8 tp : ffffffff81414880 t0 : 0000000000000020
[    0.044882][    T0]  t1 : 0098968000000000 t2 : 0000000000000000 s0 : ffffffff81403de0
[    0.044967][    T0]  s1 : 0000000000000000 a0 : 0000000000000001 a1 : 0000000000000100
[    0.045046][    T0]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.045124][    T0]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000054494d45
[    0.045210][    T0]  s2 : ffffffff80003b94 s3 : ffffffff81a8f1b0 s4 : ffffffff80e27b50
[    0.045289][    T0]  s5 : ffffffff81414880 s6 : ffffffff8160fa00 s7 : 00000000800120e8
[    0.045389][    T0]  s8 : 0000000080013100 s9 : 000000000000007f s10: 0000000000000000
[    0.045474][    T0]  s11: 0000000000000000 t3 : 7fffffffffffffff t4 : 0000000000000000
[    0.045548][    T0]  t5 : 0000000000000000 t6 : ffffffff814aa368
[    0.045620][    T0] status: 0000000200000100 badaddr: 00000000000000f8 cause: 000000000000000d
[    0.046402][    T0] [<ffffffff80003b94>] restore_all+0x12/0x6e

This because the $fp(aka. $s0) register is not used as frame pointer in the
assembly entry code.

	resume_kernel:
		REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
		bnez s0, restore_all
		REG_L s0, TASK_TI_FLAGS(tp)
                andi s0, s0, _TIF_NEED_RESCHED
                beqz s0, restore_all
                call preempt_schedule_irq
                j restore_all

To fix above issue, here we add one extra level wrapper for function
trace_hardirqs_{on,off}() so they can be safely called by low level entry
code.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: 3c4697982982 ("riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-02-24 20:30:30 -08:00

71 lines
1.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
#
# Makefile for the RISC-V Linux kernel
#
ifdef CONFIG_FTRACE
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_patch.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_sbi.o = $(CC_FLAGS_FTRACE)
endif
CFLAGS_syscall_table.o += $(call cc-option,-Wno-override-init,)
ifdef CONFIG_KEXEC
AFLAGS_kexec_relocate.o := -mcmodel=medany $(call cc-option,-mno-relax)
endif
extra-y += head.o
extra-y += vmlinux.lds
obj-y += soc.o
obj-y += cpu.o
obj-y += cpufeature.o
obj-y += entry.o
obj-y += irq.o
obj-y += process.o
obj-y += ptrace.o
obj-y += reset.o
obj-y += setup.o
obj-y += signal.o
obj-y += syscall_table.o
obj-y += sys_riscv.o
obj-y += time.o
obj-y += traps.o
obj-y += riscv_ksyms.o
obj-y += stacktrace.o
obj-y += cacheinfo.o
obj-y += patch.o
obj-y += probes/
obj-$(CONFIG_MMU) += vdso.o vdso/
obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
obj-$(CONFIG_FPU) += fpu.o
obj-$(CONFIG_SMP) += smpboot.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_SMP) += cpu_ops.o
obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o
obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o
obj-$(CONFIG_TRACE_IRQFLAGS) += trace_irq.o
obj-$(CONFIG_RISCV_BASE_PMU) += perf_event.o
obj-$(CONFIG_PERF_EVENTS) += perf_callchain.o
obj-$(CONFIG_HAVE_PERF_REGS) += perf_regs.o
obj-$(CONFIG_RISCV_SBI) += sbi.o
ifeq ($(CONFIG_RISCV_SBI), y)
obj-$(CONFIG_SMP) += cpu_ops_sbi.o
endif
obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_KEXEC) += kexec_relocate.o crash_save_regs.o machine_kexec.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_EFI) += efi.o