linux-hardened/arch/mips/kernel
Paul Burton bb9bc4689b MIPS: Calculate microMIPS ra properly when unwinding the stack
get_frame_info() calculates the offset of the return address within a
stack frame simply by dividing a the bottom 16 bits of the instruction,
treated as a signed integer, by the size of a long. Whilst this works
for MIPS32 & MIPS64 ISAs where the sw or sd instructions are used, it's
incorrect for microMIPS where encodings differ. The result is that we
typically completely fail to unwind the stack on microMIPS.

Fix this by adjusting is_ra_save_ins() to calculate the return address
offset, and take into account the various different encodings there in
the same place as we consider whether an instruction is storing the
ra/$31 register.

With this we are now able to unwind the stack for kernels targetting the
microMIPS ISA, for example we can produce:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    [<8011ea17>] __warn+0x9b/0xac
    [<8011ea45>] warn_slowpath_fmt+0x1d/0x20
    [<8013fe53>] register_console+0x43/0x314
    [<8067c58d>] of_setup_earlycon+0x1dd/0x1ec
    [<8067f63f>] early_init_dt_scan_chosen_stdout+0xe7/0xf8
    [<8066c115>] do_early_param+0x75/0xac
    [<801302f9>] parse_args+0x1dd/0x308
    [<8066c459>] parse_early_options+0x25/0x28
    [<8066c48b>] parse_early_param+0x2f/0x38
    [<8066e8cf>] setup_arch+0x113/0x488
    [<8066c4f3>] start_kernel+0x57/0x328
    ---[ end trace 0000000000000000 ]---

Whereas previously we only produced:

    Call Trace:
    [<80109e1f>] show_stack+0x63/0x7c
    ---[ end trace 0000000000000000 ]---

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 34c2f668d0 ("MIPS: microMIPS: Add unaligned access support.")
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14532/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03 16:34:37 +01:00
..
.gitignore
8250-platform.c
asm-offsets.c MIPS: Introduce irq_stack 2017-01-03 16:34:34 +01:00
binfmt_elfn32.c MIPS: kernel: Audit and remove any unnecessary uses of module.h 2016-10-05 01:31:20 +02:00
binfmt_elfo32.c MIPS: kernel: Audit and remove any unnecessary uses of module.h 2016-10-05 01:31:20 +02:00
bmips_5xxx_init.S MIPS: BMIPS: Make whitespacely correct. 2016-05-09 12:00:01 +02:00
bmips_vec.S MIPS: BMIPS: Add Whirlwind (BMIPS5200) initialization code 2016-05-09 12:00:01 +02:00
branch.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
cevt-bcm1480.c MIPS: cevt-bcm1480: Migrate to new 'set-state' interface 2015-09-03 12:07:51 +02:00
cevt-ds1287.c MIPS: cevt-ds1287: Migrate to new 'set-state' interface 2015-09-03 12:07:51 +02:00
cevt-gt641xx.c MIPS: cevt-gt641xx: Migrate to new 'set-state' interface 2015-09-03 12:07:51 +02:00
cevt-r4k.c MIPS: Fix r4k clockevents registration 2016-07-24 11:59:48 +02:00
cevt-sb1250.c MIPS: cevt-sb1250: Migrate to new 'set-state' interface 2015-09-03 12:07:52 +02:00
cevt-txx9.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
cps-vec-ns16550.S MIPS: CPS: Early debug using an ns16550-compatible UART 2015-11-11 08:34:25 +01:00
cps-vec.S MIPS: CPS: Copy EVA configuration when starting secondary VPs. 2016-05-28 12:35:05 +02:00
cpu-bugs64.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
cpu-probe.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
crash.c mips/panic: replace smp_send_stop() with kdump friendly version in panic path 2016-10-11 15:06:32 -07:00
crash_dump.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
csrc-bcm1480.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
csrc-ioasic.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
csrc-r4k.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
csrc-sb1250.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
early_printk.c
early_printk_8250.c
elf.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-08-06 09:13:11 -04:00
entry.S MIPS: kernel: entry.S: Set correct ISA level for mips_ihb 2015-04-10 15:41:46 +02:00
ftrace.c ftrace: Add return address pointer to ftrace_ret_stack 2016-08-24 12:15:14 +02:00
genex.S MIPS: Switch to the irq_stack in interrupts 2017-01-03 16:34:34 +01:00
gpio_txx9.c MIPS: txx9: switch to gpiochip_add_data() 2016-02-19 09:51:44 +01:00
head.S MIPS: store the appended dtb address in a variable 2016-08-02 14:00:16 +02:00
i8253.c
idle.c MIPS: Loongson: Add Loongson-3A R2 basic support 2016-05-13 14:02:14 +02:00
irq-gt641xx.c
irq-msc01.c
irq-rm7000.c
irq.c MIPS: Introduce irq_stack 2017-01-03 16:34:34 +01:00
irq_txx9.c
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kgdb.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
kprobes.c MIPS: tracing: disable uprobe/kprobe on compact branch instructions 2016-10-06 17:37:40 +02:00
linux32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
machine_kexec.c mips/panic: replace smp_send_stop() with kdump friendly version in panic path 2016-10-11 15:06:32 -07:00
Makefile MIPS: Factor o32 specific code into signal_o32.c 2016-08-02 11:02:35 +02:00
mcount.S
mips-cm.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
mips-cpc.c MIPS: CPC: Provide default mips_cpc_default_phys_base to ignore CPC 2016-11-04 00:17:46 +01:00
mips-mt-fpaff.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mips-mt.c
mips-r2-to-r6-emul.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mips_ksyms.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mips_machine.c
module-rela.c MIPS: module: fix incorrect IS_ERR_VALUE macro usages 2016-05-13 14:02:11 +02:00
module.c MIPS: Migrate exception table users off module.h and onto extable.h 2016-10-04 16:13:57 +02:00
octeon_switch.S MIPS: Fix octeon FP context switch handling 2015-10-02 19:16:06 +02:00
perf_event.c perf core: Add a 'nr' field to perf_event_callchain_context 2016-05-16 23:11:51 -03:00
perf_event_mipsxx.c MIPS: perf: Fix I6400 event numbers 2016-05-17 11:05:07 +02:00
pm-cps.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
pm.c MIPS: Fix watchpoint restoration 2016-05-09 12:00:02 +02:00
probes-common.h MIPS: tracing: disable uprobe/kprobe on compact branch instructions 2016-10-06 17:37:40 +02:00
proc.c MIPS: Move identification of VP(E) into proc.c from smp-mt.c 2016-10-04 16:13:57 +02:00
process.c MIPS: Calculate microMIPS ra properly when unwinding the stack 2017-01-03 16:34:37 +01:00
prom.c MIPS: Fix build with CONFIG_OF=y for non OF-enabled targets 2015-08-03 09:25:00 +02:00
ptrace.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ptrace32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
r4k_fpu.S MIPS: Use copy_s.fmt rather than copy_u.fmt 2016-05-09 12:00:04 +02:00
r4k_switch.S MIPS: Remove redundant asm/pgtable-bits.h inclusions 2016-05-13 15:30:25 +02:00
r2300_fpu.S MIPS: Correct MIPS I FP sigcontext layout 2016-11-04 01:39:23 +01:00
r2300_switch.S MIPS: Fix R2300 FP context switch handling 2015-10-02 19:16:46 +02:00
r6000_fpu.S MIPS: Fix ISA I/II FP signal context offsets 2016-11-04 01:38:52 +01:00
relocate.c MIPS: Relocatable: Provide plat_post_relocation hook 2017-01-03 16:34:36 +01:00
relocate_kernel.S MIPS: Replace add and sub instructions in relocate_kernel.S with addiu 2015-08-03 15:26:30 +02:00
reset.c MIPS: Provide fallback reboot/poweroff/halt implementations 2015-04-01 17:21:58 +02:00
rtlx-cmp.c
rtlx-mt.c
rtlx.c MIPS: rtlx: Remove KERN_DEBUG from pr_debug() arguments in rtlx.c 2014-11-24 07:44:04 +01:00
scall32-o32.S MIPS: Wire up new pkey_{mprotect,alloc,free} syscalls 2016-10-14 11:05:13 -07:00
scall64-64.S MIPS: Wire up new pkey_{mprotect,alloc,free} syscalls 2016-10-14 11:05:13 -07:00
scall64-n32.S MIPS: Wire up new pkey_{mprotect,alloc,free} syscalls 2016-10-14 11:05:13 -07:00
scall64-o32.S MIPS: Wire up new pkey_{mprotect,alloc,free} syscalls 2016-10-14 11:05:13 -07:00
segment.c MIPS: Print segment physical address when EU=1 2016-07-28 11:44:30 +02:00
setup.c MIPS: Fix max_low_pfn with disabled highmem 2016-11-04 01:45:22 +01:00
signal-common.h MIPS: Save MSA extended context around signals 2015-09-03 12:07:59 +02:00
signal.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-08-06 09:13:11 -04:00
signal32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signal_n32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signal_o32.c MIPS: Factor o32 specific code into signal_o32.c 2016-08-02 11:02:35 +02:00
smp-bmips.c MIPS: SMP: Update cpu_foreign_map on CPU disable 2016-07-29 10:19:28 +02:00
smp-cmp.c MIPS: Make smp CMP, CPS and MT use the new generic IPI functions 2016-02-25 10:56:58 +01:00
smp-cps.c MIPS: smp-cps: Avoid BUG() when offlining pre-r6 CPUs 2016-09-29 18:59:49 +02:00
smp-mt.c MIPS: Move identification of VP(E) into proc.c from smp-mt.c 2016-10-04 16:13:57 +02:00
smp-up.c
smp.c MIPS: kernel: Audit and remove any unnecessary uses of module.h 2016-10-05 01:31:20 +02:00
spinlock_test.c MIPS: Declare mips_debugfs_dir in a header 2015-10-26 09:49:42 +01:00
spram.c MIPS: Add P6600 cases to CPU switch statements 2016-05-13 14:01:52 +02:00
stacktrace.c MIPS: Add LATENCYTOP support 2015-11-11 08:36:46 +01:00
sync-r4k.c MIPS: sync-r4k: reduce skew while synchronization 2016-01-24 01:31:51 +01:00
syscall.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sysrq.c MIPS: Refactor dumping of TLB registers for r3k/r4k 2015-09-03 12:07:45 +02:00
time.c MIPS: Return -ENODEV from weak implementation of rtc_mips_set_time 2016-12-11 11:19:04 +01:00
topology.c
traps.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
unaligned.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
uprobes.c MIPS: tracing: disable uprobe/kprobe on compact branch instructions 2016-10-06 17:37:40 +02:00
vdso.c MIPS: vDSO: Fix Malta EVA mapping to vDSO page structs 2016-09-21 15:56:10 +02:00
vmlinux.lds.S MIPS: Ensure bss section ends on a long-aligned address 2017-01-03 16:34:36 +01:00
vpe-cmp.c
vpe-mt.c
vpe.c module: use a structure to encapsulate layout. 2015-12-04 22:46:25 +01:00
watch.c MIPS: Add and use watch register field definitions 2016-05-13 14:02:13 +02:00