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Switch to SPDX tags #37

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lategoodbye opened this issue Sep 2, 2018 · 5 comments
Open

Switch to SPDX tags #37

lategoodbye opened this issue Sep 2, 2018 · 5 comments

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@lategoodbye
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Most of the BCM2835/Raspberry Pi drivers doesn't use SPDX tags.

Current list:

./drivers/dma/bcm2835-dma.c
./drivers/mailbox/bcm2835-mailbox.c
./drivers/spi/spi-bcm2835.c
./drivers/spi/spi-bcm2835aux.c
./drivers/mmc/host/bcm2835.c
./drivers/pinctrl/bcm/pinctrl-bcm2835.c
./drivers/pwm/pwm-bcm2835.c
./drivers/clk/bcm/clk-bcm2835-aux.c
./drivers/clk/bcm/clk-bcm2835.c
./drivers/thermal/broadcom/bcm2835_thermal.c
./drivers/i2c/busses/i2c-bcm2835.c
./drivers/clocksource/bcm2835_timer.c
./drivers/irqchip/irq-bcm2835.c
./drivers/char/hw_random/bcm2835-rng.c
./arch/arm/mach-bcm/board_bcm2835.c
./sound/soc/bcm/bcm2835-i2s.c
./drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
./drivers/firmware/raspberrypi.c
./drivers/soc/bcm/raspberrypi-power.c

Notes:
Do not forget the header files. Do not send a single for all changes, instead one for each topic.

@lategoodbye
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Here is the first version (without the panel driver):
https://github.com/lategoodbye/rpi-zero/tree/bcm2835-spdx

@lategoodbye
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While we are at this, we should make sure that MODULE_LICENSE match SPDX identifier:
GPL-2.0+ => GPL
GPL-2.0 => GPL v2

@lategoodbye
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First patch series is out:
https://marc.info/?l=linux-arm-kernel&m=154029287612664&w=2

@lategoodbye
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The first series has been applied, the second is here:
https://marc.info/?l=linux-arm-kernel&m=154185962726576&w=2

@lategoodbye
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Most of these patches has been applied. So send a new version to address Mark Brown comments for spi and ASoC patches.

lategoodbye pushed a commit that referenced this issue Sep 1, 2019
Donald reported this sequence:
  ip next add id 1 blackhole
  ip next add id 2 blackhole
  ip ro add 1.1.1.1/32 nhid 1
  ip ro add 1.1.1.2/32 nhid 2

would cause a crash. Backtrace is:

[  151.302790] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  151.304043] CPU: 1 PID: 277 Comm: ip Not tainted 5.3.0-rc5+ #37
[  151.305078] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
[  151.306526] RIP: 0010:fib_add_nexthop+0x8b/0x2aa
[  151.307343] Code: 35 f7 81 48 8d 14 01 c7 02 f1 f1 f1 f1 c7 42 04 01 f4 f4 f4 48 89 f2 48 c1 ea 03 65 48 8b 0c 25 28 00 00 00 48 89 4d d0 31 c9 <80> 3c 02 00 74 08 48 89 f7 e8 1a e8 53 ff be 08 00 00 00 4c 89 e7
[  151.310549] RSP: 0018:ffff888116c27340 EFLAGS: 00010246
[  151.311469] RAX: dffffc0000000000 RBX: ffff8881154ece00 RCX: 0000000000000000
[  151.312713] RDX: 0000000000000004 RSI: 0000000000000020 RDI: ffff888115649b40
[  151.313968] RBP: ffff888116c273d8 R08: ffffed10221e3757 R09: ffff888110f1bab8
[  151.315212] R10: 0000000000000001 R11: ffff888110f1bab3 R12: ffff888115649b40
[  151.316456] R13: 0000000000000020 R14: ffff888116c273b0 R15: ffff888115649b40
[  151.317707] FS:  00007f60b4d8d800(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000
[  151.319113] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  151.320119] CR2: 0000555671ffdc00 CR3: 00000001136ba005 CR4: 0000000000020ee0
[  151.321367] Call Trace:
[  151.321820]  ? fib_nexthop_info+0x635/0x635
[  151.322572]  fib_dump_info+0xaa4/0xde0
[  151.323247]  ? fib_create_info+0x2431/0x2431
[  151.324008]  ? napi_alloc_frag+0x2a/0x2a
[  151.324711]  rtmsg_fib+0x2c4/0x3be
[  151.325339]  fib_table_insert+0xe2f/0xeee
...

fib_dump_info incorrectly has nhs = 0 for blackhole nexthops, so it
believes the nexthop object is a multipath group (nhs != 1) and ends
up down the nexthop_mpath_fill_node() path which is wrong for a
blackhole.

The blackhole check in nexthop_num_path is leftover from early days
of the blackhole implementation which did not initialize the device.
In the end the design was simpler (fewer special case checks) to set
the device to loopback in nh_info, so the check in nexthop_num_path
should have been removed.

Fixes: 430a049 ("nexthop: Add support for nexthop groups")
Reported-by: Donald Sharp <[email protected]>
Signed-off-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
lategoodbye pushed a commit that referenced this issue May 7, 2022
We received a report[1] of kernel crashes when Cilium is used in XDP
mode with virtio_net after updating to newer kernels. After
investigating the reason it turned out that when using mergeable bufs
with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf()
calculates the build_skb address wrong because the offset can become less
than the headroom so it gets the address of the previous page (-X bytes
depending on how lower offset is):
 page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256

This is a pr_err() I added in the beginning of page_to_skb which clearly
shows offset that is less than headroom by adding 4 bytes of metadata
via an xdp prog. The calculations done are:
 receive_mergeable():
 headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes
 offset = xdp.data - page_address(xdp_page) -
          vi->hdr_len - metasize;

 page_to_skb():
 p = page_address(page) + offset;
 ...
 buf = p - headroom;

Now buf goes -4 bytes from the page's starting address as can be seen
above which is set as skb->head and skb->data by build_skb later. Depending
on what's done with the skb (when it's freed most often) we get all kinds
of corruptions and BUG_ON() triggers in mm[2]. We have to recalculate
the new headroom after the xdp program has run, similar to how offset
and len are recalculated. Headroom is directly related to
data_hard_start, data and data_meta, so we use them to get the new size.
The result is correct (similar pr_err() in page_to_skb, one case of
xdp_page and one case of virtnet buf):
 a) Case with 4 bytes of metadata
 [  115.949641] page_to_skb: page addr ffff8b4dcfad2000 offset 252 headroom 252
 [  121.084105] page_to_skb: page addr ffff8b4dcf018000 offset 20732 headroom 252
 b) Case of pushing data +32 bytes
 [  153.181401] page_to_skb: page addr ffff8b4dd0c4d000 offset 288 headroom 288
 [  158.480421] page_to_skb: page addr ffff8b4dd00b0000 offset 24864 headroom 288
 c) Case of pushing data -33 bytes
 [  835.906830] page_to_skb: page addr ffff8b4dd3270000 offset 223 headroom 223
 [  840.839910] page_to_skb: page addr ffff8b4dcdd68000 offset 12511 headroom 223

Offset and headroom are equal because offset points to the start of
reserved bytes for the virtio_net header which are at buf start +
headroom, while data points at buf start + vnet hdr size + headroom so
when data or data_meta are adjusted by the xdp prog both the headroom size
and the offset change equally. We can use data_hard_start to compute the
new headroom after the xdp prog (linearized / page start case, the
virtnet buf case is similar just with bigger base offset):
 xdp.data_hard_start = page_address + vnet_hdr
 xdp.data = page_address + vnet_hdr + headroom
 new headroom after xdp prog = xdp.data - xdp.data_hard_start - metasize

An example reproducer xdp prog[3] is below.

[1] cilium/cilium#19453

[2] Two of the many traces:
 [   40.437400] BUG: Bad page state in process swapper/0  pfn:14940
 [   40.916726] BUG: Bad page state in process systemd-resolve  pfn:053b7
 [   41.300891] kernel BUG at include/linux/mm.h:720!
 [   41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
 [   41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G    B   W         5.18.0-rc1+ #37
 [   41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
 [   41.306018] RIP: 0010:page_frag_free+0x79/0xe0
 [   41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6
 [   41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292
 [   41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000
 [   41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff
 [   41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff
 [   41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600
 [   41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c
 [   41.317700] FS:  00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000
 [   41.319150] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [   41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0
 [   41.321387] Call Trace:
 [   41.321819]  <TASK>
 [   41.322193]  skb_release_data+0x13f/0x1c0
 [   41.322902]  __kfree_skb+0x20/0x30
 [   41.343870]  tcp_recvmsg_locked+0x671/0x880
 [   41.363764]  tcp_recvmsg+0x5e/0x1c0
 [   41.384102]  inet_recvmsg+0x42/0x100
 [   41.406783]  ? sock_recvmsg+0x1d/0x70
 [   41.428201]  sock_read_iter+0x84/0xd0
 [   41.445592]  ? 0xffffffffa3000000
 [   41.462442]  new_sync_read+0x148/0x160
 [   41.479314]  ? 0xffffffffa3000000
 [   41.496937]  vfs_read+0x138/0x190
 [   41.517198]  ksys_read+0x87/0xc0
 [   41.535336]  do_syscall_64+0x3b/0x90
 [   41.551637]  entry_SYSCALL_64_after_hwframe+0x44/0xae
 [   41.568050] RIP: 0033:0x48765b
 [   41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
 [   41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000
 [   41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b
 [   41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016
 [   41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4
 [   41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9
 [   41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff
 [   41.744254]  </TASK>
 [   41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net

 and

 [   33.524802] BUG: Bad page state in process systemd-network  pfn:11e60
 [   33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e
 [   33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60
 [   33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
 [   33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000
 [   33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000
 [   33.532471] page dumped because: nonzero mapcount
 [   33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net
 [   33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37
 [   33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
 [   33.532484] Call Trace:
 [   33.532496]  <TASK>
 [   33.532500]  dump_stack_lvl+0x45/0x5a
 [   33.532506]  bad_page.cold+0x63/0x94
 [   33.532510]  free_pcp_prepare+0x290/0x420
 [   33.532515]  free_unref_page+0x1b/0x100
 [   33.532518]  skb_release_data+0x13f/0x1c0
 [   33.532524]  kfree_skb_reason+0x3e/0xc0
 [   33.532527]  ip6_mc_input+0x23c/0x2b0
 [   33.532531]  ip6_sublist_rcv_finish+0x83/0x90
 [   33.532534]  ip6_sublist_rcv+0x22b/0x2b0

[3] XDP program to reproduce(xdp_pass.c):
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>

 SEC("xdp_pass")
 int xdp_pkt_pass(struct xdp_md *ctx)
 {
          bpf_xdp_adjust_head(ctx, -(int)32);
          return XDP_PASS;
 }

 char _license[] SEC("license") = "GPL";

 compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o
 load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass

CC: [email protected]
CC: Jason Wang <[email protected]>
CC: Xuan Zhuo <[email protected]>
CC: Daniel Borkmann <[email protected]>
CC: "Michael S. Tsirkin" <[email protected]>
CC: [email protected]
Fixes: 8fb7da9 ("virtio_net: get build_skb() buf by data ptr")
Signed-off-by: Nikolay Aleksandrov <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Acked-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
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