Граф коммитов

29 Коммитов

Автор SHA1 Сообщение Дата
Changbin Du 6a00ef4493
riscv: eliminate unreliable __builtin_frame_address(1)
I tried different pieces of code which uses __builtin_frame_address(1)
(with both gcc version 7.5.0 and 10.3.0) to verify whether it works as
expected on riscv64. The result is negative.

What the compiler had generated is as below:
31                      fp = (unsigned long)__builtin_frame_address(1);
   0xffffffff80006024 <+200>:   ld      s1,0(s0)

It takes '0(s0)' as the address of frame 1 (caller), but the actual address
should be '-16(s0)'.

          |       ...       | <-+
          +-----------------+   |
          | return address  |   |
          | previous fp     |   |
          | saved registers |   |
          | local variables |   |
  $fp --> |       ...       |   |
          +-----------------+   |
          | return address  |   |
          | previous fp --------+
          | saved registers |
  $sp --> | local variables |
          +-----------------+

This leads the kernel can not dump the full stack trace on riscv.

[    7.222126][    T1] Call Trace:
[    7.222804][    T1] [<ffffffff80006058>] dump_backtrace+0x2c/0x3a

This problem is not exposed on most riscv builds just because the '0(s0)'
occasionally is the address frame 2 (caller's caller), if only ra and fp
are stored in frame 1 (caller).

          |       ...       | <-+
          +-----------------+   |
          | return address  |   |
  $fp --> | previous fp     |   |
          +-----------------+   |
          | return address  |   |
          | previous fp --------+
          | saved registers |
  $sp --> | local variables |
          +-----------------+

This could be a *bug* of gcc that should be fixed. But as noted in gcc
manual "Calling this function with a nonzero argument can have
unpredictable effects, including crashing the calling program.", let's
remove the '__builtin_frame_address(1)' in backtrace code.

With this fix now it can show full stack trace:
[   10.444838][    T1] Call Trace:
[   10.446199][    T1] [<ffffffff8000606c>] dump_backtrace+0x2c/0x3a
[   10.447711][    T1] [<ffffffff800060ac>] show_stack+0x32/0x3e
[   10.448710][    T1] [<ffffffff80a005c0>] dump_stack_lvl+0x58/0x7a
[   10.449941][    T1] [<ffffffff80a005f6>] dump_stack+0x14/0x1c
[   10.450929][    T1] [<ffffffff804c04ee>] ubsan_epilogue+0x10/0x5a
[   10.451869][    T1] [<ffffffff804c092e>] __ubsan_handle_load_invalid_value+0x6c/0x78
[   10.453049][    T1] [<ffffffff8018f834>] __pagevec_release+0x62/0x64
[   10.455476][    T1] [<ffffffff80190830>] truncate_inode_pages_range+0x132/0x5be
[   10.456798][    T1] [<ffffffff80190ce0>] truncate_inode_pages+0x24/0x30
[   10.457853][    T1] [<ffffffff8045bb04>] kill_bdev+0x32/0x3c
...

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: eac2f3059e ("riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-02-04 10:12:32 -08:00
Peter Zijlstra 1614b2b11f arch: Make ARCH_STACKWALK independent of STACKTRACE
Make arch_stack_walk() available for ARCH_STACKWALK architectures
without it being entangled in STACKTRACE.

Link: https://lore.kernel.org/lkml/20211022152104.356586621@infradead.org/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[Mark: rebase, drop unnecessary arm change]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20211129142849.3056714-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-10 14:06:03 +00:00
Kees Cook 42a20f86dc sched: Add wrapper for get_wchan() to keep task blocked
Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
2021-10-15 11:25:14 +02:00
Jisheng Zhang 78d9d8005e
riscv: stacktrace: Fix NULL pointer dereference
When CONFIG_FRAME_POINTER=y, calling dump_stack() can always trigger
NULL pointer dereference panic similar as below:

[    0.396060] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47
[    0.396692] Hardware name: riscv-virtio,qemu (DT)
[    0.397176] Call Trace:
[    0.398191] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000960
[    0.399487] Oops [#1]
[    0.399739] Modules linked in:
[    0.400135] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47
[    0.400570] Hardware name: riscv-virtio,qemu (DT)
[    0.400926] epc : walk_stackframe+0xc4/0xdc
[    0.401291]  ra : dump_backtrace+0x30/0x38
[    0.401630] epc : ffffffff80004922 ra : ffffffff8000496a sp : ffffffe000f3bd00
[    0.402115]  gp : ffffffff80cfdcb8 tp : ffffffe000f30000 t0 : ffffffff80d0b0cf
[    0.402602]  t1 : ffffffff80d0b0c0 t2 : 0000000000000000 s0 : ffffffe000f3bd60
[    0.403071]  s1 : ffffffff808bc2e8 a0 : 0000000000001000 a1 : 0000000000000000
[    0.403448]  a2 : ffffffff803d7088 a3 : ffffffff808bc2e8 a4 : 6131725dbc24d400
[    0.403820]  a5 : 0000000000001000 a6 : 0000000000000002 a7 : ffffffffffffffff
[    0.404226]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
[    0.404634]  s5 : ffffffff803d7088 s6 : ffffffff808bc2e8 s7 : ffffffff80630650
[    0.405085]  s8 : ffffffff80912a80 s9 : 0000000000000008 s10: ffffffff804000fc
[    0.405388]  s11: 0000000000000000 t3 : 0000000000000043 t4 : ffffffffffffffff
[    0.405616]  t5 : 000000000000003d t6 : ffffffe000f3baa8
[    0.405793] status: 0000000000000100 badaddr: 0000000000000960 cause: 000000000000000d
[    0.406135] [<ffffffff80004922>] walk_stackframe+0xc4/0xdc
[    0.407032] [<ffffffff8000496a>] dump_backtrace+0x30/0x38
[    0.407797] [<ffffffff803d7100>] show_stack+0x40/0x4c
[    0.408234] [<ffffffff803d9e5c>] dump_stack+0x90/0xb6
[    0.409019] [<ffffffff8040423e>] ptdump_init+0x20/0xc4
[    0.409681] [<ffffffff800015b6>] do_one_initcall+0x4c/0x226
[    0.410110] [<ffffffff80401094>] kernel_init_freeable+0x1f4/0x258
[    0.410562] [<ffffffff803dba88>] kernel_init+0x22/0x148
[    0.410959] [<ffffffff800029e2>] ret_from_exception+0x0/0x14
[    0.412241] ---[ end trace b2ab92c901b96251 ]---
[    0.413099] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

The reason is the task is NULL when we finally call walk_stackframe()
the NULL is passed from __dump_stack():

|static void __dump_stack(void)
|{
|        dump_stack_print_info(KERN_DEFAULT);
|        show_stack(NULL, NULL, KERN_DEFAULT);
|}

Fix this issue by checking "task == NULL" case in walk_stackframe().

Fixes: eac2f3059e ("riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Wende Tan <twd2.me@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-24 12:58:51 -07:00
Jisheng Zhang 76f5dfacfb
riscv: stacktrace: pin the task's stack in get_wchan
Pin the task's stack before calling walk_stackframe() in get_wchan().
This can fix the panic as reported by Andreas when CONFIG_VMAP_STACK=y:

[   65.609696] Unable to handle kernel paging request at virtual address ffffffd0003bbde8
[   65.610460] Oops [#1]
[   65.610626] Modules linked in: virtio_blk virtio_mmio rtc_goldfish btrfs blake2b_generic libcrc32c xor raid6_pq sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua efivarfs
[   65.611670] CPU: 2 PID: 1 Comm: systemd Not tainted 5.14.0-rc1-1.g34fe32a-default #1 openSUSE Tumbleweed (unreleased) c62f7109153e5a0897ee58ba52393ad99b070fd2
[   65.612334] Hardware name: riscv-virtio,qemu (DT)
[   65.613008] epc : get_wchan+0x5c/0x88
[   65.613334]  ra : get_wchan+0x42/0x88
[   65.613625] epc : ffffffff800048a4 ra : ffffffff8000488a sp : ffffffd00021bb90
[   65.614008]  gp : ffffffff817709f8 tp : ffffffe07fe91b80 t0 : 00000000000001f8
[   65.614411]  t1 : 0000000000020000 t2 : 0000000000000000 s0 : ffffffd00021bbd0
[   65.614818]  s1 : ffffffd0003bbdf0 a0 : 0000000000000001 a1 : 0000000000000002
[   65.615237]  a2 : ffffffff81618008 a3 : 0000000000000000 a4 : 0000000000000000
[   65.615637]  a5 : ffffffd0003bc000 a6 : 0000000000000002 a7 : ffffffe27d370000
[   65.616022]  s2 : ffffffd0003bbd90 s3 : ffffffff8071a81e s4 : 0000000000003fff
[   65.616407]  s5 : ffffffffffffc000 s6 : 0000000000000000 s7 : ffffffff81618008
[   65.616845]  s8 : 0000000000000001 s9 : 0000000180000040 s10: 0000000000000000
[   65.617248]  s11: 000000000000016b t3 : 000000ff00000000 t4 : 0c6aec92de5e3fd7
[   65.617672]  t5 : fff78f60608fcfff t6 : 0000000000000078
[   65.618088] status: 0000000000000120 badaddr: ffffffd0003bbde8 cause: 000000000000000d
[   65.618621] [<ffffffff800048a4>] get_wchan+0x5c/0x88
[   65.619008] [<ffffffff8022da88>] do_task_stat+0x7a2/0xa46
[   65.619325] [<ffffffff8022e87e>] proc_tgid_stat+0xe/0x16
[   65.619637] [<ffffffff80227dd6>] proc_single_show+0x46/0x96
[   65.619979] [<ffffffff801ccb1e>] seq_read_iter+0x190/0x31e
[   65.620341] [<ffffffff801ccd70>] seq_read+0xc4/0x104
[   65.620633] [<ffffffff801a6bfe>] vfs_read+0x6a/0x112
[   65.620922] [<ffffffff801a701c>] ksys_read+0x54/0xbe
[   65.621206] [<ffffffff801a7094>] sys_read+0xe/0x16
[   65.621474] [<ffffffff8000303e>] ret_from_syscall+0x0/0x2
[   65.622169] ---[ end trace f24856ed2b8789c5 ]---
[   65.622832] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-23 17:29:03 -07:00
Peter Zijlstra b03fbd4ff2 sched: Introduce task_is_running()
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
2021-06-18 11:43:07 +02:00
Chen Huang eac2f3059e
riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled
As [1] and [2] said, the arch_stack_walk should not to trace itself, or it will
leave the trace unexpectedly when called. The example is when we do "cat
/sys/kernel/debug/page_owner", all pages' stack is the same.

arch_stack_walk+0x18/0x20
stack_trace_save+0x40/0x60
register_dummy_stack+0x24/0x5e
init_page_owner+0x2e

So we use __builtin_frame_address(1) as the first frame to be walked. And mark
the arch_stack_walk() noinline.

We found that pr_cont will affact pages' stack whose task state is RUNNING when
testing "echo t > /proc/sysrq-trigger". So move the place of pr_cont and mark
the function dump_backtrace() noinline.

Also we move the case when task == NULL into else branch, and test for it in
"echo c > /proc/sysrq-trigger".

[1] https://lore.kernel.org/lkml/20210319184106.5688-1-mark.rutland@arm.com/
[2] https://lore.kernel.org/lkml/20210317142050.57712-1-chenjun102@huawei.com/

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Fixes: 5d8544e2d0 ("RISC-V: Generic library routines and assembly")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22 18:59:20 -07:00
Kefeng Wang 23c1075ae8
riscv: Drop const annotation for sp
The const annotation should not be used for 'sp', or it will
become read only and lead to bad stack output.

Fixes: dec822771b ("riscv: stacktrace: Move register keyword to beginning of declaration")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-01 21:37:03 -07:00
Linus Torvalds 8b83369ddc RISC-V Patches for the 5.12 Merge Window
I have a handful of new RISC-V related patches for this merge window:
 
 * A check to ensure drivers are properly using uaccess.  This isn't
   manifesting with any of the drivers I'm currently using, but may catch
   errors in new drivers.
 * Some preliminary support for the FU740, along with the HiFive
   Unleashed it will appear on.
 * NUMA support for RISC-V, which involves making the arm64 code generic.
 * Support for kasan on the vmalloc region.
 * A handful of new drivers for the Kendryte K210, along with the DT
   plumbing required to boot on a handful of K210-based boards.
 * Support for allocating ASIDs.
 * Preliminary support for kernels larger than 128MiB.
 * Various other improvements to our KASAN support, including the
   utilization of huge pages when allocating the KASAN regions.
 
 We may have already found a bug with the KASAN_VMALLOC code, but it's
 passing my tests.  There's a fix in the works, but that will probably
 miss the merge window.
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Merge tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "A handful of new RISC-V related patches for this merge window:

   - A check to ensure drivers are properly using uaccess. This isn't
     manifesting with any of the drivers I'm currently using, but may
     catch errors in new drivers.

   - Some preliminary support for the FU740, along with the HiFive
     Unleashed it will appear on.

   - NUMA support for RISC-V, which involves making the arm64 code
     generic.

   - Support for kasan on the vmalloc region.

   - A handful of new drivers for the Kendryte K210, along with the DT
     plumbing required to boot on a handful of K210-based boards.

   - Support for allocating ASIDs.

   - Preliminary support for kernels larger than 128MiB.

   - Various other improvements to our KASAN support, including the
     utilization of huge pages when allocating the KASAN regions.

  We may have already found a bug with the KASAN_VMALLOC code, but it's
  passing my tests. There's a fix in the works, but that will probably
  miss the merge window.

* tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (75 commits)
  riscv: Improve kasan population by using hugepages when possible
  riscv: Improve kasan population function
  riscv: Use KASAN_SHADOW_INIT define for kasan memory initialization
  riscv: Improve kasan definitions
  riscv: Get rid of MAX_EARLY_MAPPING_SIZE
  soc: canaan: Sort the Makefile alphabetically
  riscv: Disable KSAN_SANITIZE for vDSO
  riscv: Remove unnecessary declaration
  riscv: Add Canaan Kendryte K210 SD card defconfig
  riscv: Update Canaan Kendryte K210 defconfig
  riscv: Add Kendryte KD233 board device tree
  riscv: Add SiPeed MAIXDUINO board device tree
  riscv: Add SiPeed MAIX GO board device tree
  riscv: Add SiPeed MAIX DOCK board device tree
  riscv: Add SiPeed MAIX BiT board device tree
  riscv: Update Canaan Kendryte K210 device tree
  dt-bindings: add resets property to dw-apb-timer
  dt-bindings: fix sifive gpio properties
  dt-bindings: update sifive uart compatible string
  dt-bindings: update sifive clint compatible string
  ...
2021-02-26 10:28:35 -08:00
Kefeng Wang dec822771b
riscv: stacktrace: Move register keyword to beginning of declaration
Using global sp_in_global directly to fix the following warning,

arch/riscv/kernel/stacktrace.c:31:3: warning: ‘register’ is not at beginning of declaration [-Wold-style-declaration]
31 |   const register unsigned long current_sp = sp_in_global;
   |   ^~~~~

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 18:31:47 -08:00
Chen Huang f766f77a74
riscv/stacktrace: Fix stack output without ra on the stack top
When a function doesn't have a callee, then it will not
push ra into the stack, such as lkdtm_BUG() function,

addi	sp,sp,-16
sd	s0,8(sp)
addi	s0,sp,16
ebreak

The struct stackframe use {fp,ra} to get information from
stack, if walk_stackframe() with pr_regs, we will obtain
wrong value and bad stacktrace,

[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
---[ end trace 18da3fbdf08e25d5 ]---

Correct the next fp and pc, after that, full stacktrace
shown as expects,

[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
[<ffffffe0008b24a4>] lkdtm_do_action+0x14/0x1c
[<ffffffe00066c372>] direct_entry+0xc0/0x10a
[<ffffffe000439f86>] full_proxy_write+0x42/0x6a
[<ffffffe000309626>] vfs_write+0x7e/0x214
[<ffffffe00030992a>] ksys_write+0x98/0xc0
[<ffffffe000309960>] sys_write+0xe/0x16
[<ffffffe0002014bc>] ret_from_syscall+0x0/0x2
---[ end trace 61917f3d9a9fadcd ]---

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:13 -08:00
Kefeng Wang 091b945085
riscv: Add dump stack in show_regs
Like commit 1149aad10b ("arm64: Add dump_backtrace() in show_regs"),
dump the stack in riscv show_regs as common code expects.

Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:11 -08:00
Kefeng Wang 5cb0080f1b
riscv: Enable ARCH_STACKWALK
Convert to ARCH_STACKWALK to reduce duplicated code in stack trace.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-11-25 16:03:59 -08:00
Kefeng Wang 9dd97064e2
riscv: Make stack walk callback consistent with generic code
In order to use generic arch_stack_walk() code, make stack walk
callback consistent with it.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-11-20 18:53:38 -08:00
Kefeng Wang 99c168fccb
riscv: Cleanup stacktrace
1. add asm/stacktrace.h for walk_stackframe and struct stackframe
2. remove unnecessary blank lines in stacktrace.c
3. fix warning "no previous prototype for ‘fill_callchain’"

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-11-20 18:53:31 -08:00
Dmitry Safonov 9cb8f069de kernel: rename show_stack_loglvl() => show_stack()
Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Dmitry Safonov 0b3d436574 riscv: add show_stack_loglvl()
Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-28-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:11 -07:00
Dmitry Safonov 2062a4e8ae kallsyms/printk: add loglvl to print_ip_sym()
Patch series "Add log level to show_stack()", v3.

Add log level argument to show_stack().

Done in three stages:
1. Introducing show_stack_loglvl() for every architecture
2. Migrating old users with an explicit log level
3. Renaming show_stack_loglvl() into show_stack()

Justification:

- It's a design mistake to move a business-logic decision into platform
  realization detail.

- I have currently two patches sets that would benefit from this work:
  Removing console_loglevel jumps in sysrq driver [1] Hung task warning
  before panic [2] - suggested by Tetsuo (but he probably didn't realise
  what it would involve).

- While doing (1), (2) the backtraces were adjusted to headers and other
  messages for each situation - so there won't be a situation when the
  backtrace is printed, but the headers are missing because they have
  lesser log level (or the reverse).

- As the result in (2) plays with console_loglevel for kdb are removed.

The least important for upstream, but maybe still worth to note that every
company I've worked in so far had an off-list patch to print backtrace
with the needed log level (but only for the architecture they cared
about).  If you have other ideas how you will benefit from show_stack()
with a log level - please, reply to this cover letter.

See also discussion on v1:
https://lore.kernel.org/linux-riscv/20191106083538.z5nlpuf64cigxigh@pathway.suse.cz/

This patch (of 50):

print_ip_sym() needs to have a log level parameter to comply with other
parts being printed.  Otherwise, half of the expected backtrace would be
printed and other may be missing with some logging level.

The following callee(s) are using now the adjusted log level:
- microblaze/unwind: the same level as headers & userspace unwind.
  Note that pr_debug()'s there are for debugging the unwinder itself.
- nds32/traps: symbol addresses are printed with the same log level
  as backtrace headers.
- lockdep: ip for locking issues is printed with the same log level
  as other part of the warning.
- sched: ip where preemption was disabled is printed as error like
  the rest part of the message.
- ftrace: bug reports are now consistent in the log level being used.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-2-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:10 -07:00
Kefeng Wang 0502bee37c
riscv: stacktrace: Fix undefined reference to `walk_stackframe'
Drop static declaration to fix following build error if FRAME_POINTER disabled,
  riscv64-linux-ld: arch/riscv/kernel/perf_callchain.o: in function `.L0':
  perf_callchain.c:(.text+0x2b8): undefined reference to `walk_stackframe'

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-12 17:04:25 -07:00
Guenter Roeck af2bdf828f
RISC-V: stacktrace: Declare sp_in_global outside ifdef
riscv:allnoconfig and riscv:tinyconfig fail to compile.

arch/riscv/kernel/stacktrace.c: In function 'walk_stackframe':
arch/riscv/kernel/stacktrace.c:78:8: error: 'sp_in_global' undeclared

sp_in_global is declared inside CONFIG_FRAME_POINTER but used outside
of it.

Fixes: 52e7c52d2d ("RISC-V: Stop relying on GCC's register allocator's hueristics")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-21 10:50:45 -07:00
Palmer Dabbelt 52e7c52d2d
RISC-V: Stop relying on GCC's register allocator's hueristics
GCC allows users to hint to the register allocation that a variable should be
placed in a register by using a syntax along the lines of

    function(...) {
        register long in_REG __asm__("REG");
    }

We've abused this a bit throughout the RISC-V port to access fixed registers
directly as C variables.  In practice it's never going to blow up because GCC
isn't going to allocate these registers, but it's not a well defined syntax so
we really shouldn't be relying upon this.  Luckily there is a very similar but
well defined syntax that allows us to still access these registers directly as
C variables, which is to simply declare the register variables globally.  For
fixed variables this doesn't change the ABI.

LLVM disallows this ambiguous syntax, so this isn't just strictly a formatting
change.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-03 10:28:13 -08:00
Mao Han dbeb90b0c1 riscv: Add perf callchain support
This patch add support for perf callchain sampling on riscv platforms.
The return address of leaf function is retrieved from pt_regs as
it is not saved in the outmost frame.

Signed-off-by: Mao Han <han_mao@c-sky.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: linux-riscv <linux-riscv@lists.infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Guo Ren <guoren@kernel.org>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
[paul.walmsley@sifive.com: fixed some 'checkpatch.pl --strict' issues;
 fixed patch description spelling]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-04 12:43:00 -07:00
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00
Linus Torvalds b0bb1269b9 RISC-V Patches for the 5.2 Merge Window, Part 1 v3
This patch set contains an assortment of RISC-V related patches that I'd
 like to target for the 5.2 merge window.  Most of the patches are
 cleanups, but there are a handful of user-visible changes:
 
 * The nosmp and nr_cpus command-line arguments are now supported, which
   work like normal.
 * The SBI console no longer installs itself as a preferred console, we
   rely on standard mechanisms (/chosen, command-line, hueristics)
   instead.
 * sfence_remove_sfence_vma{,_asid} now pass their arguments along to the
   SBI call.
 * Modules now support BUG().
 * A missing sfence.vma during boot has been added.  This bug only
   manifests during boot.
 * The arch/riscv support for SiFive's L2 cache controller has been
   merged, which should un-block the EDAC framework work.
 
 I've only tested this on QEMU again, as I didn't have time to get things
 running on the Unleashed.  The latest master from this morning merges in
 cleanly and passes the tests as well.
 
 This patch set rebased my "5.2 MW, Part 1" patch set which includes an
 erronous empty file.  It's also a rebase of my "5.2 MW, Part 2" patch
 set, in which I managed to create another file while attempting to
 remove the empty file.
 
 Sorry for all the noise!
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 YWJiZWx0LmNvbQAKCRDvTKFQLMurQXV/D/9nz8KYxNKOVIXft27mw93Qnx5joblg
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 c3tX/U8o39H0Kg==
 =mZwx
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains an assortment of RISC-V related patches that I'd like to
  target for the 5.2 merge window. Most of the patches are cleanups, but
  there are a handful of user-visible changes:

   - The nosmp and nr_cpus command-line arguments are now supported,
     which work like normal.

   - The SBI console no longer installs itself as a preferred console,
     we rely on standard mechanisms (/chosen, command-line, hueristics)
     instead.

   - sfence_remove_sfence_vma{,_asid} now pass their arguments along to
     the SBI call.

   - Modules now support BUG().

   - A missing sfence.vma during boot has been added. This bug only
     manifests during boot.

   - The arch/riscv support for SiFive's L2 cache controller has been
     merged, which should un-block the EDAC framework work.

  I've only tested this on QEMU again, as I didn't have time to get
  things running on the Unleashed. The latest master from this morning
  merges in cleanly and passes the tests as well"

* tag 'riscv-for-linus-5.2-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (31 commits)
  riscv: fix locking violation in page fault handler
  RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs
  RISC-V: Add DT documentation for SiFive L2 Cache Controller
  RISC-V: Avoid using invalid intermediate translations
  riscv: Support BUG() in kernel module
  riscv: Add the support for c.ebreak check in is_valid_bugaddr()
  riscv: support trap-based WARN()
  riscv: fix sbi_remote_sfence_vma{,_asid}.
  riscv: move switch_mm to its own file
  riscv: move flush_icache_{all,mm} to cacheflush.c
  tty: Don't force RISCV SBI console as preferred console
  RISC-V: Access CSRs using CSR numbers
  RISC-V: Add interrupt related SCAUSE defines in asm/csr.h
  RISC-V: Use tabs to align macro values in asm/csr.h
  RISC-V: Fix minor checkpatch issues.
  RISC-V: Support nr_cpus command line option.
  RISC-V: Implement nosmp commandline option.
  RISC-V: Add RISC-V specific arch_match_cpu_phys_id
  riscv: vdso: drop unnecessary cc-ldoption
  riscv: call pm_power_off from machine_halt / machine_power_off
  ...
2019-05-19 09:56:36 -07:00
Christoph Hellwig 6ab77af4b0
riscv: remove duplicate macros from ptrace.h
No need to have two names for the same thing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:11 -07:00
Christoph Hellwig 877425424d
riscv: remove unreachable !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR code
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR is always defined for RISC-V.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:11 -07:00
Thomas Gleixner fa9833992d riscv/stacktrace: Remove the pointless ULONG_MAX marker
Terminating the last trace entry with ULONG_MAX is a completely pointless
exercise and none of the consumers can rely on it because it's
inconsistently implemented across architectures. In fact quite some of the
callers remove the entry and adjust stack_trace.nr_entries afterwards.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: linux-riscv@lists.infradead.org
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Link: https://lkml.kernel.org/r/20190410103644.131061192@linutronix.de
2019-04-14 19:58:28 +02:00
Alan Kao b785ec129b
riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
In walk_stackframe, the pc now receives the address from calling
ftrace_graph_ret_addr instead of manual calculation.

Note that the original calculation,
        pc = frame->ra - 4
is buggy when the instruction at the return address happened to be a
compressed inst. But since it is not a critical part of ftrace, it is
ignored for now to ease the review process.

Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:13 -07:00
Palmer Dabbelt 5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00