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[RK3399] Kernel 4.4.x fails to build with GCC 9.1.0 #160

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5schatten opened this issue May 13, 2019 · 0 comments
Open

[RK3399] Kernel 4.4.x fails to build with GCC 9.1.0 #160

5schatten opened this issue May 13, 2019 · 0 comments

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@5schatten
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I tried to compile this Kernel commit for a RK3399 board and used the LibreELEC build system but it failed:

In file included from /home/supervisedthinking/git/libreelec-rr/LibreELEC.tv/build.LibreELEC-RK3399.arm-9.1-devel/toolchain/armv8a-libreelec-linux-gnueabi/sysroot/usr/include/string.h:494,
                 from fs/fs.c:7:
In function 'strncpy',
    inlined from 'fs__env_override' at fs/fs.c:191:2,
    inlined from 'fs__get_mountpoint' at fs/fs.c:197:6:
/home/supervisedthinking/git/libreelec-rr/LibreELEC.tv/build.LibreELEC-RK3399.arm-9.1-devel/toolchain/armv8a-libreelec-linux-gnueabi/sysroot/usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 4096 equals destination size [-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

I also tried the latest stable & dev version but all fail with the same errors.

Build log:
https://pastebin.com/v9C8Q6Xi

0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Oct 5, 2019
There is a kernel panic that is triggered when reading /proc/kpageflags
on the kernel booted with kernel parameter 'memmap=nn[KMG]!ss[KMG]':

  BUG: unable to handle kernel paging request at fffffffffffffffe
  PGD 9b20e067 P4D 9b20e067 PUD 9b210067 PMD 0
  Oops: 0000 [FireflyTeam#1] SMP PTI
  CPU: 2 PID: 1728 Comm: page-types Not tainted 4.17.0-rc6-mm1-v4.17-rc6-180605-0816-00236-g2dfb086ef02c+ rockchip-linux#160
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014
  RIP: 0010:stable_page_flags+0x27/0x3c0
  Code: 00 00 00 0f 1f 44 00 00 48 85 ff 0f 84 a0 03 00 00 41 54 55 49 89 fc 53 48 8b 57 08 48 8b 2f 48 8d 42 ff 83 e2 01 48 0f 44 c7 <48> 8b 00 f6 c4 01 0f 84 10 03 00 00 31 db 49 8b 54 24 08 4c 89 e7
  RSP: 0018:ffffbbd44111fde0 EFLAGS: 00010202
  RAX: fffffffffffffffe RBX: 00007fffffffeff9 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: 0000000000000202 RDI: ffffed1182fff5c0
  RBP: ffffffffffffffff R08: 0000000000000001 R09: 0000000000000001
  R10: ffffbbd44111fed8 R11: 0000000000000000 R12: ffffed1182fff5c0
  R13: 00000000000bffd7 R14: 0000000002fff5c0 R15: ffffbbd44111ff10
  FS:  00007efc4335a500(0000) GS:ffff93a5bfc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: fffffffffffffffe CR3: 00000000b2a58000 CR4: 00000000001406e0
  Call Trace:
   kpageflags_read+0xc7/0x120
   proc_reg_read+0x3c/0x60
   __vfs_read+0x36/0x170
   vfs_read+0x89/0x130
   ksys_pread64+0x71/0x90
   do_syscall_64+0x5b/0x160
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7efc42e75e23
  Code: 09 00 ba 9f 01 00 00 e8 ab 81 f4 ff 66 2e 0f 1f 84 00 00 00 00 00 90 83 3d 29 0a 2d 00 00 75 13 49 89 ca b8 11 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 db d3 01 00 48 89 04 24

According to kernel bisection, this problem became visible due to commit
f7f9910 ("mm: stop zeroing memory during allocation in vmemmap")
which changes how struct pages are initialized.

Memblock layout affects the pfn ranges covered by node/zone.  Consider
that we have a VM with 2 NUMA nodes and each node has 4GB memory, and
the default (no memmap= given) memblock layout is like below:

  MEMBLOCK configuration:
   memory size = 0x00000001fff75c00 reserved size = 0x000000000300c000
   memory.cnt  = 0x4
   memory[0x0]     [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0
   memory[0x1]     [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0
   memory[0x2]     [0x0000000100000000-0x000000013fffffff], 0x0000000040000000 bytes on node 0 flags: 0x0
   memory[0x3]     [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0
   ...

If you give memmap=1G!4G (so it just covers memory[0x2]),
the range [0x100000000-0x13fffffff] is gone:

  MEMBLOCK configuration:
   memory size = 0x00000001bff75c00 reserved size = 0x000000000300c000
   memory.cnt  = 0x3
   memory[0x0]     [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0
   memory[0x1]     [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0
   memory[0x2]     [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0
   ...

This causes shrinking node 0's pfn range because it is calculated by the
address range of memblock.memory.  So some of struct pages in the gap
range are left uninitialized.

We have a function zero_resv_unavail() which does zeroing the struct pages
within the reserved unavailable range (i.e.  memblock.memory &&
!memblock.reserved).  This patch utilizes it to cover all unavailable
ranges by putting them into memblock.reserved.

Link: http://lkml.kernel.org/r/20180615072947.GB23273@hori1.linux.bs1.fc.nec.co.jp
Fixes: f7f9910 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Tested-by: Oscar Salvador <osalvador@suse.de>
Tested-by: "Herton R. Krzesinski" <herton@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
0lvin pushed a commit to free-z4u/roc-rk3328-cc-official that referenced this issue Oct 6, 2019
The change protects almost the whole body of u_audio_iso_complete()
function by PCM stream lock, this is mainly sufficient to avoid a race
between USB request completion and stream termination, the change
prevents a possibility of invalid memory access in interrupt context
by memcpy():

    Unable to handle kernel paging request at virtual address 00004e80
    pgd = c0004000
    [00004e80] *pgd=00000000
    Internal error: Oops: 817 [FireflyTeam#1] PREEMPT SMP ARM
    CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G         C   3.14.54+ rockchip-linux#117
    task: da180b80 ti: da192000 task.ti: da192000
    PC is at memcpy+0x50/0x330
    LR is at 0xcdd92b0e
    pc : [<c029ef30>]    lr : [<cdd92b0e>]    psr: 20000193
    sp : da193ce4  ip : dd86ae26  fp : 0000b180
    r10: daf81680  r9 : 00000000  r8 : d58a01ea
    r7 : 2c0b43e4  r6 : acdfb08b  r5 : 01a271cf  r4 : 87389377
    r3 : 69469782  r2 : 00000020  r1 : daf82fe0  r0 : 00004e80
    Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    Control: 10c5387d  Table: 2b70804a  DAC: 00000015
    Process ksoftirqd/0 (pid: 3, stack limit = 0xda192238)

Also added a check for potential !runtime condition, commonly it is
done by PCM_RUNTIME_CHECK(substream) in the beginning, however this
does not completely prevent from oopses in u_audio_iso_complete(),
because the proper protection scheme must be implemented in PCM
library functions.

An example of *not fixed* oops due to substream->runtime->*
dereference by snd_pcm_running(substream) from
snd_pcm_period_elapsed(), where substream->runtime is gone while
waiting the substream lock:

    Unable to handle kernel paging request at virtual address 6b6b6b6b
    pgd = db7e4000
    [6b6b6b6b] *pgd=00000000
    CPU: 0 PID: 193 Comm: klogd Tainted: G         C   3.14.54+ rockchip-linux#118
    task: db5ac500 ti: db60c000 task.ti: db60c000
    PC is at snd_pcm_period_elapsed+0x48/0xd8 [snd_pcm]
    LR is at snd_pcm_period_elapsed+0x40/0xd8 [snd_pcm]
    pc : [<>]    lr : [<>]    psr: 60000193
    Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
    Control: 10c5387d  Table: 2b7e404a  DAC: 00000015
    Process klogd (pid: 193, stack limit = 0xdb60c238)
    [<>] (snd_pcm_period_elapsed [snd_pcm]) from [<>] (udc_irq+0x500/0xbbc)
    [<>] (udc_irq) from [<>] (ci_irq+0x280/0x304)
    [<>] (ci_irq) from [<>] (handle_irq_event_percpu+0xa4/0x40c)
    [<>] (handle_irq_event_percpu) from [<>] (handle_irq_event+0x3c/0x5c)
    [<>] (handle_irq_event) from [<>] (handle_fasteoi_irq+0xc4/0x110)
    [<>] (handle_fasteoi_irq) from [<>] (generic_handle_irq+0x20/0x30)
    [<>] (generic_handle_irq) from [<>] (handle_IRQ+0x80/0xc0)
    [<>] (handle_IRQ) from [<>] (gic_handle_irq+0x3c/0x60)
    [<>] (gic_handle_irq) from [<>] (__irq_svc+0x44/0x78)

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
[erosca: W/o this patch, with minimal instrumentation [1], I can
         consistently reproduce BUG: KASAN: use-after-free [2]]

[1] Instrumentation to reproduce issue [2]:
 diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
 index a72295c953bb..bd0b308024fe 100644
 --- a/drivers/usb/gadget/function/u_audio.c
 +++ b/drivers/usb/gadget/function/u_audio.c
 @@ -16,6 +16,7 @@
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
 +#include <linux/delay.h>

  #include "u_audio.h"

 @@ -147,6 +148,8 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)

 	spin_unlock_irqrestore(&prm->lock, flags);

 +	udelay(500); //delay here to increase probability of parallel activities
 +
 	/* Pack USB load in ALSA ring buffer */
 	pending = prm->dma_bytes - hw_ptr;

[2] After applying [1], below BUG occurs on Rcar-H3-Salvator-X board:
==================================================================
BUG: KASAN: use-after-free in u_audio_iso_complete+0x24c/0x520 [u_audio]
Read of size 8 at addr ffff8006cafcc248 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        WC      4.14.47+ rockchip-linux#160
Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
Call trace:
[<ffff2000080925ac>] dump_backtrace+0x0/0x364
[<ffff200008092924>] show_stack+0x14/0x1c
[<ffff200008f8dbcc>] dump_stack+0x108/0x174
[<ffff2000083c71b8>] print_address_description+0x7c/0x32c
[<ffff2000083c78e8>] kasan_report+0x324/0x354
[<ffff2000083c6114>] __asan_load8+0x24/0x94
[<ffff2000021d1b34>] u_audio_iso_complete+0x24c/0x520 [u_audio]
[<ffff20000152fe50>] usb_gadget_giveback_request+0x480/0x4d0 [udc_core]
[<ffff200001860ab8>] usbhsg_queue_done+0x100/0x130 [renesas_usbhs]
[<ffff20000185f814>] usbhsf_pkt_handler+0x1a4/0x298 [renesas_usbhs]
[<ffff20000185fb38>] usbhsf_irq_ready+0x128/0x178 [renesas_usbhs]
[<ffff200001859cc8>] usbhs_interrupt+0x440/0x490 [renesas_usbhs]
[<ffff2000081a0288>] __handle_irq_event_percpu+0x594/0xa58
[<ffff2000081a07d0>] handle_irq_event_percpu+0x84/0x12c
[<ffff2000081a0928>] handle_irq_event+0xb0/0x10c
[<ffff2000081a8384>] handle_fasteoi_irq+0x1e0/0x2ec
[<ffff20000819e5f8>] generic_handle_irq+0x2c/0x44
[<ffff20000819f0d0>] __handle_domain_irq+0x190/0x194
[<ffff20000808177c>] gic_handle_irq+0x80/0xac
Exception stack(0xffff200009e97c80 to 0xffff200009e97dc0)
7c80: 0000000000000000 0000000000000000 0000000000000003 ffff200008179298
7ca0: ffff20000ae1c180 dfff200000000000 0000000000000000 ffff2000081f9a88
7cc0: ffff200009eb5960 ffff200009e97cf0 0000000000001600 ffff0400041b064b
7ce0: 0000000000000000 0000000000000002 0000000200000001 0000000000000001
7d00: ffff20000842197c 0000ffff958c4970 0000000000000000 ffff8006da0d5b80
7d20: ffff8006d4678498 0000000000000000 000000126bde0a8b ffff8006d4678480
7d40: 0000000000000000 000000126bdbea64 ffff200008fd0000 ffff8006fffff980
7d60: 00000000495f0018 ffff200009e97dc0 ffff200008b6c4ec ffff200009e97dc0
7d80: ffff200008b6c4f0 0000000020000145 ffff8006da0d5b80 ffff8006d4678498
7da0: ffffffffffffffff ffff8006d4678498 ffff200009e97dc0 ffff200008b6c4f0
[<ffff200008084034>] el1_irq+0xb4/0x12c
[<ffff200008b6c4f0>] cpuidle_enter_state+0x818/0x844
[<ffff200008b6c59c>] cpuidle_enter+0x18/0x20
[<ffff20000815f2e4>] call_cpuidle+0x98/0x9c
[<ffff20000815f674>] do_idle+0x214/0x264
[<ffff20000815facc>] cpu_startup_entry+0x20/0x24
[<ffff200008fb09d8>] rest_init+0x30c/0x320
[<ffff2000095f1338>] start_kernel+0x570/0x5b0
---<-snip->---

Fixes: 132fcb4 ("usb: gadget: Add Audio Class 2.0 Driver")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
StephenInVamrs referenced this issue in radxa/kernel Jan 2, 2020
…ream spinlock

The change protects almost the whole body of u_audio_iso_complete()
function by PCM stream lock, this is mainly sufficient to avoid a race
between USB request completion and stream termination, the change
prevents a possibility of invalid memory access in interrupt context
by memcpy():

    Unable to handle kernel paging request at virtual address 00004e80
    pgd = c0004000
    [00004e80] *pgd=00000000
    Internal error: Oops: 817 [#1] PREEMPT SMP ARM
    CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G         C   3.14.54+ #117
    task: da180b80 ti: da192000 task.ti: da192000
    PC is at memcpy+0x50/0x330
    LR is at 0xcdd92b0e
    pc : [<c029ef30>]    lr : [<cdd92b0e>]    psr: 20000193
    sp : da193ce4  ip : dd86ae26  fp : 0000b180
    r10: daf81680  r9 : 00000000  r8 : d58a01ea
    r7 : 2c0b43e4  r6 : acdfb08b  r5 : 01a271cf  r4 : 87389377
    r3 : 69469782  r2 : 00000020  r1 : daf82fe0  r0 : 00004e80
    Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    Control: 10c5387d  Table: 2b70804a  DAC: 00000015
    Process ksoftirqd/0 (pid: 3, stack limit = 0xda192238)

Also added a check for potential !runtime condition, commonly it is
done by PCM_RUNTIME_CHECK(substream) in the beginning, however this
does not completely prevent from oopses in u_audio_iso_complete(),
because the proper protection scheme must be implemented in PCM
library functions.

An example of *not fixed* oops due to substream->runtime->*
dereference by snd_pcm_running(substream) from
snd_pcm_period_elapsed(), where substream->runtime is gone while
waiting the substream lock:

    Unable to handle kernel paging request at virtual address 6b6b6b6b
    pgd = db7e4000
    [6b6b6b6b] *pgd=00000000
    CPU: 0 PID: 193 Comm: klogd Tainted: G         C   3.14.54+ #118
    task: db5ac500 ti: db60c000 task.ti: db60c000
    PC is at snd_pcm_period_elapsed+0x48/0xd8 [snd_pcm]
    LR is at snd_pcm_period_elapsed+0x40/0xd8 [snd_pcm]
    pc : [<>]    lr : [<>]    psr: 60000193
    Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
    Control: 10c5387d  Table: 2b7e404a  DAC: 00000015
    Process klogd (pid: 193, stack limit = 0xdb60c238)
    [<>] (snd_pcm_period_elapsed [snd_pcm]) from [<>] (udc_irq+0x500/0xbbc)
    [<>] (udc_irq) from [<>] (ci_irq+0x280/0x304)
    [<>] (ci_irq) from [<>] (handle_irq_event_percpu+0xa4/0x40c)
    [<>] (handle_irq_event_percpu) from [<>] (handle_irq_event+0x3c/0x5c)
    [<>] (handle_irq_event) from [<>] (handle_fasteoi_irq+0xc4/0x110)
    [<>] (handle_fasteoi_irq) from [<>] (generic_handle_irq+0x20/0x30)
    [<>] (generic_handle_irq) from [<>] (handle_IRQ+0x80/0xc0)
    [<>] (handle_IRQ) from [<>] (gic_handle_irq+0x3c/0x60)
    [<>] (gic_handle_irq) from [<>] (__irq_svc+0x44/0x78)

Change-Id: I0b0e20f1aaf7c093c7fc198128186cfb637bdbf4
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
[erosca: W/o this patch, with minimal instrumentation [1], I can
         consistently reproduce BUG: KASAN: use-after-free [2]]
[1] Instrumentation to reproduce issue [2]:
 diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
 index a72295c953bb..bd0b308024fe 100644
 --- a/drivers/usb/gadget/function/u_audio.c
 +++ b/drivers/usb/gadget/function/u_audio.c
 @@ -16,6 +16,7 @@
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
 +#include <linux/delay.h>
  #include "u_audio.h"
 @@ -147,6 +148,8 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
 	spin_unlock_irqrestore(&prm->lock, flags);
 +	udelay(500); //delay here to increase probability of parallel activities
 +
 	/* Pack USB load in ALSA ring buffer */
 	pending = prm->dma_bytes - hw_ptr;
[2] After applying [1], below BUG occurs on Rcar-H3-Salvator-X board:
==================================================================
BUG: KASAN: use-after-free in u_audio_iso_complete+0x24c/0x520 [u_audio]
Read of size 8 at addr ffff8006cafcc248 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        WC      4.14.47+ #160
Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
Call trace:
[<ffff2000080925ac>] dump_backtrace+0x0/0x364
[<ffff200008092924>] show_stack+0x14/0x1c
[<ffff200008f8dbcc>] dump_stack+0x108/0x174
[<ffff2000083c71b8>] print_address_description+0x7c/0x32c
[<ffff2000083c78e8>] kasan_report+0x324/0x354
[<ffff2000083c6114>] __asan_load8+0x24/0x94
[<ffff2000021d1b34>] u_audio_iso_complete+0x24c/0x520 [u_audio]
[<ffff20000152fe50>] usb_gadget_giveback_request+0x480/0x4d0 [udc_core]
[<ffff200001860ab8>] usbhsg_queue_done+0x100/0x130 [renesas_usbhs]
[<ffff20000185f814>] usbhsf_pkt_handler+0x1a4/0x298 [renesas_usbhs]
[<ffff20000185fb38>] usbhsf_irq_ready+0x128/0x178 [renesas_usbhs]
[<ffff200001859cc8>] usbhs_interrupt+0x440/0x490 [renesas_usbhs]
[<ffff2000081a0288>] __handle_irq_event_percpu+0x594/0xa58
[<ffff2000081a07d0>] handle_irq_event_percpu+0x84/0x12c
[<ffff2000081a0928>] handle_irq_event+0xb0/0x10c
[<ffff2000081a8384>] handle_fasteoi_irq+0x1e0/0x2ec
[<ffff20000819e5f8>] generic_handle_irq+0x2c/0x44
[<ffff20000819f0d0>] __handle_domain_irq+0x190/0x194
[<ffff20000808177c>] gic_handle_irq+0x80/0xac
Exception stack(0xffff200009e97c80 to 0xffff200009e97dc0)
7c80: 0000000000000000 0000000000000000 0000000000000003 ffff200008179298
7ca0: ffff20000ae1c180 dfff200000000000 0000000000000000 ffff2000081f9a88
7cc0: ffff200009eb5960 ffff200009e97cf0 0000000000001600 ffff0400041b064b
7ce0: 0000000000000000 0000000000000002 0000000200000001 0000000000000001
7d00: ffff20000842197c 0000ffff958c4970 0000000000000000 ffff8006da0d5b80
7d20: ffff8006d4678498 0000000000000000 000000126bde0a8b ffff8006d4678480
7d40: 0000000000000000 000000126bdbea64 ffff200008fd0000 ffff8006fffff980
7d60: 00000000495f0018 ffff200009e97dc0 ffff200008b6c4ec ffff200009e97dc0
7d80: ffff200008b6c4f0 0000000020000145 ffff8006da0d5b80 ffff8006d4678498
7da0: ffffffffffffffff ffff8006d4678498 ffff200009e97dc0 ffff200008b6c4f0
[<ffff200008084034>] el1_irq+0xb4/0x12c
[<ffff200008b6c4f0>] cpuidle_enter_state+0x818/0x844
[<ffff200008b6c59c>] cpuidle_enter+0x18/0x20
[<ffff20000815f2e4>] call_cpuidle+0x98/0x9c
[<ffff20000815f674>] do_idle+0x214/0x264
[<ffff20000815facc>] cpu_startup_entry+0x20/0x24
[<ffff200008fb09d8>] rest_init+0x30c/0x320
[<ffff2000095f1338>] start_kernel+0x570/0x5b0
---<-snip->---
Fixes: 132fcb4 ("usb: gadget: Add Audio Class 2.0 Driver")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: William Wu <william.wu@rock-chips.com>
(cherry picked from commit 56bc615)
scpcom pushed a commit to scpcom/linux that referenced this issue Apr 30, 2020
…ream spinlock

The change protects almost the whole body of u_audio_iso_complete()
function by PCM stream lock, this is mainly sufficient to avoid a race
between USB request completion and stream termination, the change
prevents a possibility of invalid memory access in interrupt context
by memcpy():

    Unable to handle kernel paging request at virtual address 00004e80
    pgd = c0004000
    [00004e80] *pgd=00000000
    Internal error: Oops: 817 [#1] PREEMPT SMP ARM
    CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G         C   3.14.54+ rockchip-linux#117
    task: da180b80 ti: da192000 task.ti: da192000
    PC is at memcpy+0x50/0x330
    LR is at 0xcdd92b0e
    pc : [<c029ef30>]    lr : [<cdd92b0e>]    psr: 20000193
    sp : da193ce4  ip : dd86ae26  fp : 0000b180
    r10: daf81680  r9 : 00000000  r8 : d58a01ea
    r7 : 2c0b43e4  r6 : acdfb08b  r5 : 01a271cf  r4 : 87389377
    r3 : 69469782  r2 : 00000020  r1 : daf82fe0  r0 : 00004e80
    Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
    Control: 10c5387d  Table: 2b70804a  DAC: 00000015
    Process ksoftirqd/0 (pid: 3, stack limit = 0xda192238)

Also added a check for potential !runtime condition, commonly it is
done by PCM_RUNTIME_CHECK(substream) in the beginning, however this
does not completely prevent from oopses in u_audio_iso_complete(),
because the proper protection scheme must be implemented in PCM
library functions.

An example of *not fixed* oops due to substream->runtime->*
dereference by snd_pcm_running(substream) from
snd_pcm_period_elapsed(), where substream->runtime is gone while
waiting the substream lock:

    Unable to handle kernel paging request at virtual address 6b6b6b6b
    pgd = db7e4000
    [6b6b6b6b] *pgd=00000000
    CPU: 0 PID: 193 Comm: klogd Tainted: G         C   3.14.54+ rockchip-linux#118
    task: db5ac500 ti: db60c000 task.ti: db60c000
    PC is at snd_pcm_period_elapsed+0x48/0xd8 [snd_pcm]
    LR is at snd_pcm_period_elapsed+0x40/0xd8 [snd_pcm]
    pc : [<>]    lr : [<>]    psr: 60000193
    Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
    Control: 10c5387d  Table: 2b7e404a  DAC: 00000015
    Process klogd (pid: 193, stack limit = 0xdb60c238)
    [<>] (snd_pcm_period_elapsed [snd_pcm]) from [<>] (udc_irq+0x500/0xbbc)
    [<>] (udc_irq) from [<>] (ci_irq+0x280/0x304)
    [<>] (ci_irq) from [<>] (handle_irq_event_percpu+0xa4/0x40c)
    [<>] (handle_irq_event_percpu) from [<>] (handle_irq_event+0x3c/0x5c)
    [<>] (handle_irq_event) from [<>] (handle_fasteoi_irq+0xc4/0x110)
    [<>] (handle_fasteoi_irq) from [<>] (generic_handle_irq+0x20/0x30)
    [<>] (generic_handle_irq) from [<>] (handle_IRQ+0x80/0xc0)
    [<>] (handle_IRQ) from [<>] (gic_handle_irq+0x3c/0x60)
    [<>] (gic_handle_irq) from [<>] (__irq_svc+0x44/0x78)

Change-Id: I0b0e20f1aaf7c093c7fc198128186cfb637bdbf4
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
[erosca: W/o this patch, with minimal instrumentation [1], I can
         consistently reproduce BUG: KASAN: use-after-free [2]]
[1] Instrumentation to reproduce issue [2]:
 diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
 index a72295c953bb..bd0b308024fe 100644
 --- a/drivers/usb/gadget/function/u_audio.c
 +++ b/drivers/usb/gadget/function/u_audio.c
 @@ -16,6 +16,7 @@
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
 +#include <linux/delay.h>
  #include "u_audio.h"
 @@ -147,6 +148,8 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
 	spin_unlock_irqrestore(&prm->lock, flags);
 +	udelay(500); //delay here to increase probability of parallel activities
 +
 	/* Pack USB load in ALSA ring buffer */
 	pending = prm->dma_bytes - hw_ptr;
[2] After applying [1], below BUG occurs on Rcar-H3-Salvator-X board:
==================================================================
BUG: KASAN: use-after-free in u_audio_iso_complete+0x24c/0x520 [u_audio]
Read of size 8 at addr ffff8006cafcc248 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        WC      4.14.47+ rockchip-linux#160
Hardware name: Renesas Salvator-X board based on r8a7795 ES2.0+ (DT)
Call trace:
[<ffff2000080925ac>] dump_backtrace+0x0/0x364
[<ffff200008092924>] show_stack+0x14/0x1c
[<ffff200008f8dbcc>] dump_stack+0x108/0x174
[<ffff2000083c71b8>] print_address_description+0x7c/0x32c
[<ffff2000083c78e8>] kasan_report+0x324/0x354
[<ffff2000083c6114>] __asan_load8+0x24/0x94
[<ffff2000021d1b34>] u_audio_iso_complete+0x24c/0x520 [u_audio]
[<ffff20000152fe50>] usb_gadget_giveback_request+0x480/0x4d0 [udc_core]
[<ffff200001860ab8>] usbhsg_queue_done+0x100/0x130 [renesas_usbhs]
[<ffff20000185f814>] usbhsf_pkt_handler+0x1a4/0x298 [renesas_usbhs]
[<ffff20000185fb38>] usbhsf_irq_ready+0x128/0x178 [renesas_usbhs]
[<ffff200001859cc8>] usbhs_interrupt+0x440/0x490 [renesas_usbhs]
[<ffff2000081a0288>] __handle_irq_event_percpu+0x594/0xa58
[<ffff2000081a07d0>] handle_irq_event_percpu+0x84/0x12c
[<ffff2000081a0928>] handle_irq_event+0xb0/0x10c
[<ffff2000081a8384>] handle_fasteoi_irq+0x1e0/0x2ec
[<ffff20000819e5f8>] generic_handle_irq+0x2c/0x44
[<ffff20000819f0d0>] __handle_domain_irq+0x190/0x194
[<ffff20000808177c>] gic_handle_irq+0x80/0xac
Exception stack(0xffff200009e97c80 to 0xffff200009e97dc0)
7c80: 0000000000000000 0000000000000000 0000000000000003 ffff200008179298
7ca0: ffff20000ae1c180 dfff200000000000 0000000000000000 ffff2000081f9a88
7cc0: ffff200009eb5960 ffff200009e97cf0 0000000000001600 ffff0400041b064b
7ce0: 0000000000000000 0000000000000002 0000000200000001 0000000000000001
7d00: ffff20000842197c 0000ffff958c4970 0000000000000000 ffff8006da0d5b80
7d20: ffff8006d4678498 0000000000000000 000000126bde0a8b ffff8006d4678480
7d40: 0000000000000000 000000126bdbea64 ffff200008fd0000 ffff8006fffff980
7d60: 00000000495f0018 ffff200009e97dc0 ffff200008b6c4ec ffff200009e97dc0
7d80: ffff200008b6c4f0 0000000020000145 ffff8006da0d5b80 ffff8006d4678498
7da0: ffffffffffffffff ffff8006d4678498 ffff200009e97dc0 ffff200008b6c4f0
[<ffff200008084034>] el1_irq+0xb4/0x12c
[<ffff200008b6c4f0>] cpuidle_enter_state+0x818/0x844
[<ffff200008b6c59c>] cpuidle_enter+0x18/0x20
[<ffff20000815f2e4>] call_cpuidle+0x98/0x9c
[<ffff20000815f674>] do_idle+0x214/0x264
[<ffff20000815facc>] cpu_startup_entry+0x20/0x24
[<ffff200008fb09d8>] rest_init+0x30c/0x320
[<ffff2000095f1338>] start_kernel+0x570/0x5b0
---<-snip->---
Fixes: 132fcb4 ("usb: gadget: Add Audio Class 2.0 Driver")
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: William Wu <william.wu@rock-chips.com>
(cherry picked from commit 56bc615)
friendlyarm pushed a commit to friendlyarm/kernel-rockchip that referenced this issue Jun 15, 2021
[ Upstream commit 0f20615 ]

Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable
bitfields. Missing breaks in a switch caused 8-byte reads always. This can
confuse libbpf because it does strict checks that memory load size corresponds
to the original size of the field, which in this case quite often would be
wrong.

After fixing that, we run into another problem, which quite subtle, so worth
documenting here. The issue is in Clang optimization and CO-RE relocation
interactions. Without that asm volatile construct (also known as
barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and
will apply BYTE_OFFSET 4 times for each switch case arm. This will result in
the same error from libbpf about mismatch of memory load size and original
field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *),
*(u32 *), and *(u64 *) memory loads, three of which will fail. Using
barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to
calculate p, after which value of p is used without relocation in each of
switch case arms, doing appropiately-sized memory load.

Here's the list of relevant relocations and pieces of generated BPF code
before and after this patch for test_core_reloc_bitfields_direct selftests.

BEFORE
=====
 rockchip-linux#45: core_reloc: insn rockchip-linux#160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32
 rockchip-linux#46: core_reloc: insn rockchip-linux#167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#47: core_reloc: insn rockchip-linux#174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#48: core_reloc: insn rockchip-linux#178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#49: core_reloc: insn rockchip-linux#182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32

     157:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     159:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     160:       b7 02 00 00 04 00 00 00 r2 = 4
; BYTE_SIZE relocation here                 ^^^
     161:       66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63>
     162:       16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65>
     163:       16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66>
     164:       05 00 12 00 00 00 00 00 goto +18 <LBB0_69>

0000000000000528 <LBB0_66>:
     165:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     167:       69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     168:       05 00 0e 00 00 00 00 00 goto +14 <LBB0_69>

0000000000000548 <LBB0_63>:
     169:       16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67>
     170:       16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68>
     171:       05 00 0b 00 00 00 00 00 goto +11 <LBB0_69>

0000000000000560 <LBB0_68>:
     172:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     174:       79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     175:       05 00 07 00 00 00 00 00 goto +7 <LBB0_69>

0000000000000580 <LBB0_65>:
     176:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     178:       71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     179:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

00000000000005a0 <LBB0_67>:
     180:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     182:       61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8)
; BYTE_OFFSET relo here w/ RIGHT size        ^^^^^^^^^^^^^^^^

00000000000005b8 <LBB0_69>:
     183:       67 01 00 00 20 00 00 00 r1 <<= 32
     184:       b7 02 00 00 00 00 00 00 r2 = 0
     185:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     186:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     187:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000005e0 <LBB0_71>:
     188:       77 01 00 00 20 00 00 00 r1 >>= 32

AFTER
=====

 rockchip-linux#30: core_reloc: insn rockchip-linux#132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 rockchip-linux#31: core_reloc: insn rockchip-linux#134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32

     129:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     131:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     132:       b7 01 00 00 08 00 00 00 r1 = 8
; BYTE_OFFSET relo here                     ^^^
; no size check for non-memory dereferencing instructions
     133:       0f 12 00 00 00 00 00 00 r2 += r1
     134:       b7 03 00 00 04 00 00 00 r3 = 4
; BYTE_SIZE relocation here                 ^^^
     135:       66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63>
     136:       16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65>
     137:       16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66>
     138:       05 00 0a 00 00 00 00 00 goto +10 <LBB0_69>

0000000000000458 <LBB0_66>:
     139:       69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     140:       05 00 08 00 00 00 00 00 goto +8 <LBB0_69>

0000000000000468 <LBB0_63>:
     141:       16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67>
     142:       16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68>
     143:       05 00 05 00 00 00 00 00 goto +5 <LBB0_69>

0000000000000480 <LBB0_68>:
     144:       79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     145:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

0000000000000490 <LBB0_65>:
     146:       71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     147:       05 00 01 00 00 00 00 00 goto +1 <LBB0_69>

00000000000004a0 <LBB0_67>:
     148:       61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^

00000000000004a8 <LBB0_69>:
     149:       67 01 00 00 20 00 00 00 r1 <<= 32
     150:       b7 02 00 00 00 00 00 00 r2 = 0
     151:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     152:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     153:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000004d0 <LBB0_71>:
     154:       77 01 00 00 20 00 00 00 r1 >>= 323

Fixes: ee26dad ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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