Searched hist:2408 (Results 51 - 60 of 60) sorted by relevance

123

/linux-master/fs/fuse/
H A Dfile.cdiff 2408f6ef Fri Nov 25 08:14:30 MST 2011 Cong Wang <amwang@redhat.com> fuse: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>
/linux-master/drivers/gpu/drm/i915/
H A Di915_gem_gtt.cdiff 423a8a94 Mon Nov 06 14:11:28 MST 2017 Chris Wilson <chris@chris-wilson.co.uk> drm/i915: Deconstruct struct sgt_dma initialiser

gcc-4.4 complains about:

struct sgt_dma iter = {
.sg = vma->pages->sgl,
.dma = sg_dma_address(iter.sg),
.max = iter.dma + iter.sg->length,
};

drivers/gpu/drm/i915/i915_gem_gtt.c: In function ‘gen8_ppgtt_insert_4lvl’:
drivers/gpu/drm/i915/i915_gem_gtt.c:938: error: ‘iter.sg’ is used uninitialized in this function
drivers/gpu/drm/i915/i915_gem_gtt.c:939: error: ‘iter.dma’ is used uninitialized in this function

and worse generates invalid code that triggers a GPF:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: snd_aloop nf_conntrack_ipv6 nf_defrag_ipv6 nf_log_ipv6 ip6table_filter ip6_tables ctr ccm xt_state nf_log_ipv4
nf_log_common xt_LOG xt_limit xt_recent xt_owner xt_addrtype iptable_filter ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c ip_tables dm_mod vhost_net macvtap macvlan vhost tun kvm_intel kvm
irqbypass uas usb_storage hid_multitouch btusb btrtl uvcvideo videobuf2_v4l2 videobuf2_core videodev media videobuf2_vmalloc videobuf2_memops
sg ppdev dell_wmi sparse_keymap mei_wdt sd_mod iTCO_wdt iTCO_vendor_support rtsx_pci_ms memstick rtsx_pci_sdmmc mmc_core dell_smm_hwmon hwmon
dell_laptop dell_smbios dcdbas joydev input_leds hci_uart btintel btqca btbcm bluetooth parport_pc parport i2c_hid
intel_lpss_acpi intel_lpss pcspkr wmi int3400_thermal acpi_thermal_rel dell_rbtn mei_me mei snd_hda_codec_hdmi snd_hda_codec_realtek
snd_hda_codec_generic ahci libahci acpi_pad xhci_pci xhci_hcd snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device
snd_pcm snd_timer snd soundcore int3403_thermal arc4 e1000e ptp pps_core i2c_i801 iwlmvm mac80211 rtsx_pci iwlwifi cfg80211 rfkill
intel_pch_thermal processor_thermal_device int340x_thermal_zone intel_soc_dts_iosf i915 video fjes
CPU: 2 PID: 2408 Comm: X Not tainted 4.10.0-rc5+ #1
Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
task: ffff880219fe4740 task.stack: ffffc90005f98000
RIP: 0010:gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
RSP: 0018:ffffc90005f9b8c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8802167d8000 RCX: 0000000000000001
RDX: 00000000ffff7000 RSI: ffff880219f94140 RDI: ffff880228444000
RBP: ffffc90005f9b948 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000080
R13: 0000000000000001 R14: ffffc90005f9bcd7 R15: ffff88020c9a83c0
FS: 00007fb53e1ee920(0000) GS:ffff88024dd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000022ef95000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ppgtt_bind_vma+0x40/0x50 [i915]
i915_vma_bind+0xcb/0x1c0 [i915]
__i915_vma_do_pin+0x6e/0xd0 [i915]
i915_gem_execbuffer_reserve_vma+0x162/0x1d0 [i915]
i915_gem_execbuffer_reserve+0x4fc/0x510 [i915]
? __kmalloc+0x134/0x250
? i915_gem_wait_for_error+0x25/0x100 [i915]
? i915_gem_wait_for_error+0x25/0x100 [i915]
i915_gem_do_execbuffer+0x2df/0xa00 [i915]
? drm_malloc_gfp.clone.0+0x42/0x80 [i915]
? path_put+0x22/0x30
? __check_object_size+0x62/0x1f0
? terminate_walk+0x44/0x90
i915_gem_execbuffer2+0x95/0x1e0 [i915]
drm_ioctl+0x243/0x490
? handle_pte_fault+0x1d7/0x220
? i915_gem_do_execbuffer+0xa00/0xa00 [i915]
? handle_mm_fault+0x10d/0x2a0
vfs_ioctl+0x18/0x30
do_vfs_ioctl+0x14b/0x3f0
SyS_ioctl+0x92/0xa0
entry_SYSCALL_64_fastpath+0x1a/0xa9
RIP: 0033:0x7fb53b4fcb77
RSP: 002b:00007ffe0c572898 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb53e17c038 RCX: 00007fb53b4fcb77
RDX: 00007ffe0c572900 RSI: 0000000040406469 RDI: 000000000000000b
RBP: 00007fb5376d67e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000003246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055eecb314d00 R15: 000055eecb315460
Code: 0f 84 5d ff ff ff eb a2 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 58 0f 1f 44 00 00 31 c0 89 4d b0 <4c>
8b 60 10 44 8b 70 0c 48 89 d0 4c 8b 2e 48 c1 e8 27 25 ff 01
RIP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915] RSP: ffffc90005f9b8c8
CR2: 0000000000000010

Recent gccs, such as 4.9, 6.3 or 7.2, do not generate the warning nor do
they explode on use. If we manually create the struct using locals from
the stack, this should eliminate this issue, and does not alter code
generation with gcc-7.2.

Fixes: 894ccebee2b0 ("drm/i915: Micro-optimise gen8_ppgtt_insert_entries()")
Reported-by: Kelly French <kfrench@federalhill.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kelly French <kfrench@federalhill.net>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106211128.12538-1-chris@chris-wilson.co.uk
Tested-by: Kelly French <kfrench@federalhill.net>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
(cherry picked from commit 5684514ba9dc6d7aa932cc53d97d866b2386221f)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
diff 5684514b Mon Nov 06 14:11:28 MST 2017 Chris Wilson <chris@chris-wilson.co.uk> drm/i915: Deconstruct struct sgt_dma initialiser

gcc-4.4 complains about:

struct sgt_dma iter = {
.sg = vma->pages->sgl,
.dma = sg_dma_address(iter.sg),
.max = iter.dma + iter.sg->length,
};

drivers/gpu/drm/i915/i915_gem_gtt.c: In function ‘gen8_ppgtt_insert_4lvl’:
drivers/gpu/drm/i915/i915_gem_gtt.c:938: error: ‘iter.sg’ is used uninitialized in this function
drivers/gpu/drm/i915/i915_gem_gtt.c:939: error: ‘iter.dma’ is used uninitialized in this function

and worse generates invalid code that triggers a GPF:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: snd_aloop nf_conntrack_ipv6 nf_defrag_ipv6 nf_log_ipv6 ip6table_filter ip6_tables ctr ccm xt_state nf_log_ipv4
nf_log_common xt_LOG xt_limit xt_recent xt_owner xt_addrtype iptable_filter ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c ip_tables dm_mod vhost_net macvtap macvlan vhost tun kvm_intel kvm
irqbypass uas usb_storage hid_multitouch btusb btrtl uvcvideo videobuf2_v4l2 videobuf2_core videodev media videobuf2_vmalloc videobuf2_memops
sg ppdev dell_wmi sparse_keymap mei_wdt sd_mod iTCO_wdt iTCO_vendor_support rtsx_pci_ms memstick rtsx_pci_sdmmc mmc_core dell_smm_hwmon hwmon
dell_laptop dell_smbios dcdbas joydev input_leds hci_uart btintel btqca btbcm bluetooth parport_pc parport i2c_hid
intel_lpss_acpi intel_lpss pcspkr wmi int3400_thermal acpi_thermal_rel dell_rbtn mei_me mei snd_hda_codec_hdmi snd_hda_codec_realtek
snd_hda_codec_generic ahci libahci acpi_pad xhci_pci xhci_hcd snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device
snd_pcm snd_timer snd soundcore int3403_thermal arc4 e1000e ptp pps_core i2c_i801 iwlmvm mac80211 rtsx_pci iwlwifi cfg80211 rfkill
intel_pch_thermal processor_thermal_device int340x_thermal_zone intel_soc_dts_iosf i915 video fjes
CPU: 2 PID: 2408 Comm: X Not tainted 4.10.0-rc5+ #1
Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
task: ffff880219fe4740 task.stack: ffffc90005f98000
RIP: 0010:gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
RSP: 0018:ffffc90005f9b8c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8802167d8000 RCX: 0000000000000001
RDX: 00000000ffff7000 RSI: ffff880219f94140 RDI: ffff880228444000
RBP: ffffc90005f9b948 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000080
R13: 0000000000000001 R14: ffffc90005f9bcd7 R15: ffff88020c9a83c0
FS: 00007fb53e1ee920(0000) GS:ffff88024dd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000022ef95000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ppgtt_bind_vma+0x40/0x50 [i915]
i915_vma_bind+0xcb/0x1c0 [i915]
__i915_vma_do_pin+0x6e/0xd0 [i915]
i915_gem_execbuffer_reserve_vma+0x162/0x1d0 [i915]
i915_gem_execbuffer_reserve+0x4fc/0x510 [i915]
? __kmalloc+0x134/0x250
? i915_gem_wait_for_error+0x25/0x100 [i915]
? i915_gem_wait_for_error+0x25/0x100 [i915]
i915_gem_do_execbuffer+0x2df/0xa00 [i915]
? drm_malloc_gfp.clone.0+0x42/0x80 [i915]
? path_put+0x22/0x30
? __check_object_size+0x62/0x1f0
? terminate_walk+0x44/0x90
i915_gem_execbuffer2+0x95/0x1e0 [i915]
drm_ioctl+0x243/0x490
? handle_pte_fault+0x1d7/0x220
? i915_gem_do_execbuffer+0xa00/0xa00 [i915]
? handle_mm_fault+0x10d/0x2a0
vfs_ioctl+0x18/0x30
do_vfs_ioctl+0x14b/0x3f0
SyS_ioctl+0x92/0xa0
entry_SYSCALL_64_fastpath+0x1a/0xa9
RIP: 0033:0x7fb53b4fcb77
RSP: 002b:00007ffe0c572898 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb53e17c038 RCX: 00007fb53b4fcb77
RDX: 00007ffe0c572900 RSI: 0000000040406469 RDI: 000000000000000b
RBP: 00007fb5376d67e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000003246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055eecb314d00 R15: 000055eecb315460
Code: 0f 84 5d ff ff ff eb a2 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 58 0f 1f 44 00 00 31 c0 89 4d b0 <4c>
8b 60 10 44 8b 70 0c 48 89 d0 4c 8b 2e 48 c1 e8 27 25 ff 01
RIP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915] RSP: ffffc90005f9b8c8
CR2: 0000000000000010

Recent gccs, such as 4.9, 6.3 or 7.2, do not generate the warning nor do
they explode on use. If we manually create the struct using locals from
the stack, this should eliminate this issue, and does not alter code
generation with gcc-7.2.

Fixes: 894ccebee2b0 ("drm/i915: Micro-optimise gen8_ppgtt_insert_entries()")
Reported-by: Kelly French <kfrench@federalhill.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kelly French <kfrench@federalhill.net>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106211128.12538-1-chris@chris-wilson.co.uk
Tested-by: Kelly French <kfrench@federalhill.net>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
/linux-master/net/ipv6/
H A Dtcp_ipv6.cdiff eba20811 Mon Jul 17 08:44:45 MDT 2023 Eric Dumazet <edumazet@google.com> tcp: annotate data-races around tcp_rsk(req)->ts_recent

TCP request sockets are lockless, tcp_rsk(req)->ts_recent
can change while being read by another cpu as syzbot noticed.

This is harmless, but we should annotate the known races.

Note that tcp_check_req() changes req->ts_recent a bit early,
we might change this in the future.

BUG: KCSAN: data-race in tcp_check_req / tcp_check_req

write to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 1:
tcp_check_req+0x694/0xc70 net/ipv4/tcp_minisocks.c:762
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
do_softirq+0x7e/0xb0 kernel/softirq.c:472
__local_bh_enable_ip+0x64/0x70 kernel/softirq.c:396
local_bh_enable+0x1f/0x20 include/linux/bottom_half.h:33
rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline]
__dev_queue_xmit+0xabb/0x1d10 net/core/dev.c:4271
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
neigh_hh_output include/net/neighbour.h:528 [inline]
neigh_output include/net/neighbour.h:542 [inline]
ip_finish_output2+0x700/0x840 net/ipv4/ip_output.c:229
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:431
dst_output include/net/dst.h:458 [inline]
ip_local_out net/ipv4/ip_output.c:126 [inline]
__ip_queue_xmit+0xa4d/0xa70 net/ipv4/ip_output.c:533
ip_queue_xmit+0x38/0x40 net/ipv4/ip_output.c:547
__tcp_transmit_skb+0x1194/0x16e0 net/ipv4/tcp_output.c:1399
tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline]
tcp_write_xmit+0x13ff/0x2fd0 net/ipv4/tcp_output.c:2693
__tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:2877
tcp_push_pending_frames include/net/tcp.h:1952 [inline]
__tcp_sock_set_cork net/ipv4/tcp.c:3336 [inline]
tcp_sock_set_cork+0xe8/0x100 net/ipv4/tcp.c:3343
rds_tcp_xmit_path_complete+0x3b/0x40 net/rds/tcp_send.c:52
rds_send_xmit+0xf8d/0x1420 net/rds/send.c:422
rds_send_worker+0x42/0x1d0 net/rds/threads.c:200
process_one_work+0x3e6/0x750 kernel/workqueue.c:2408
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 0:
tcp_check_req+0x32a/0xc70 net/ipv4/tcp_minisocks.c:622
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
run_ksoftirqd+0x17/0x20 kernel/softirq.c:939
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x1cd237f1 -> 0x1cd237f2

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230717144445.653164-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
H A Daddrconf.cdiff e669b869 Mon Oct 30 23:47:09 MDT 2017 Eric Dumazet <edumazet@google.com> ipv6: addrconf: increment ifp refcount before ipv6_del_addr()

In the (unlikely) event fixup_permanent_addr() returns a failure,
addrconf_permanent_addr() calls ipv6_del_addr() without the
mandatory call to in6_ifa_hold(), leading to a refcount error,
spotted by syzkaller :

WARNING: CPU: 1 PID: 3142 at lib/refcount.c:227 refcount_dec+0x4c/0x50
lib/refcount.c:227
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3142 Comm: ip Not tainted 4.14.0-rc4-next-20171009+ #33
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:52
panic+0x1e4/0x41c kernel/panic.c:181
__warn+0x1c4/0x1e0 kernel/panic.c:544
report_bug+0x211/0x2d0 lib/bug.c:183
fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:refcount_dec+0x4c/0x50 lib/refcount.c:227
RSP: 0018:ffff8801ca49e680 EFLAGS: 00010286
RAX: 000000000000002c RBX: ffff8801d07cfcdc RCX: 0000000000000000
RDX: 000000000000002c RSI: 1ffff10039493c90 RDI: ffffed0039493cc4
RBP: ffff8801ca49e688 R08: ffff8801ca49dd70 R09: 0000000000000000
R10: ffff8801ca49df58 R11: 0000000000000000 R12: 1ffff10039493cd9
R13: ffff8801ca49e6e8 R14: ffff8801ca49e7e8 R15: ffff8801d07cfcdc
__in6_ifa_put include/net/addrconf.h:369 [inline]
ipv6_del_addr+0x42b/0xb60 net/ipv6/addrconf.c:1208
addrconf_permanent_addr net/ipv6/addrconf.c:3327 [inline]
addrconf_notify+0x1c66/0x2190 net/ipv6/addrconf.c:3393
notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
__raw_notifier_call_chain kernel/notifier.c:394 [inline]
raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1697
call_netdevice_notifiers net/core/dev.c:1715 [inline]
__dev_notify_flags+0x15d/0x430 net/core/dev.c:6843
dev_change_flags+0xf5/0x140 net/core/dev.c:6879
do_setlink+0xa1b/0x38e0 net/core/rtnetlink.c:2113
rtnl_newlink+0xf0d/0x1a40 net/core/rtnetlink.c:2661
rtnetlink_rcv_msg+0x733/0x1090 net/core/rtnetlink.c:4301
netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2408
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4313
netlink_unicast_kernel net/netlink/af_netlink.c:1273 [inline]
netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1299
netlink_sendmsg+0xa4a/0xe70 net/netlink/af_netlink.c:1862
sock_sendmsg_nosec net/socket.c:633 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:643
___sys_sendmsg+0x75b/0x8a0 net/socket.c:2049
__sys_sendmsg+0xe5/0x210 net/socket.c:2083
SYSC_sendmsg net/socket.c:2094 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2090
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x7fa9174d3320
RSP: 002b:00007ffe302ae9e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffe302b2ae0 RCX: 00007fa9174d3320
RDX: 0000000000000000 RSI: 00007ffe302aea20 RDI: 0000000000000016
RBP: 0000000000000082 R08: 0000000000000000 R09: 000000000000000f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe302b32a0
R13: 0000000000000000 R14: 00007ffe302b2ab8 R15: 00007ffe302b32b8

Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
/linux-master/net/ipv4/
H A Droute.cdiff dbd2915c Tue Jan 17 22:58:01 MST 2006 Andrew Morton <akpm@osdl.org> [IPV4]: RT_CACHE_STAT_INC() warning fix

BUG: using smp_processor_id() in preemptible [00000001] code: rpc.statd/2408

And it _is_ a bug, but I guess we don't care enough to add preempt_disable().

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
H A Dtcp_ipv4.cdiff eba20811 Mon Jul 17 08:44:45 MDT 2023 Eric Dumazet <edumazet@google.com> tcp: annotate data-races around tcp_rsk(req)->ts_recent

TCP request sockets are lockless, tcp_rsk(req)->ts_recent
can change while being read by another cpu as syzbot noticed.

This is harmless, but we should annotate the known races.

Note that tcp_check_req() changes req->ts_recent a bit early,
we might change this in the future.

BUG: KCSAN: data-race in tcp_check_req / tcp_check_req

write to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 1:
tcp_check_req+0x694/0xc70 net/ipv4/tcp_minisocks.c:762
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
do_softirq+0x7e/0xb0 kernel/softirq.c:472
__local_bh_enable_ip+0x64/0x70 kernel/softirq.c:396
local_bh_enable+0x1f/0x20 include/linux/bottom_half.h:33
rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline]
__dev_queue_xmit+0xabb/0x1d10 net/core/dev.c:4271
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
neigh_hh_output include/net/neighbour.h:528 [inline]
neigh_output include/net/neighbour.h:542 [inline]
ip_finish_output2+0x700/0x840 net/ipv4/ip_output.c:229
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:431
dst_output include/net/dst.h:458 [inline]
ip_local_out net/ipv4/ip_output.c:126 [inline]
__ip_queue_xmit+0xa4d/0xa70 net/ipv4/ip_output.c:533
ip_queue_xmit+0x38/0x40 net/ipv4/ip_output.c:547
__tcp_transmit_skb+0x1194/0x16e0 net/ipv4/tcp_output.c:1399
tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline]
tcp_write_xmit+0x13ff/0x2fd0 net/ipv4/tcp_output.c:2693
__tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:2877
tcp_push_pending_frames include/net/tcp.h:1952 [inline]
__tcp_sock_set_cork net/ipv4/tcp.c:3336 [inline]
tcp_sock_set_cork+0xe8/0x100 net/ipv4/tcp.c:3343
rds_tcp_xmit_path_complete+0x3b/0x40 net/rds/tcp_send.c:52
rds_send_xmit+0xf8d/0x1420 net/rds/send.c:422
rds_send_worker+0x42/0x1d0 net/rds/threads.c:200
process_one_work+0x3e6/0x750 kernel/workqueue.c:2408
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 0:
tcp_check_req+0x32a/0xc70 net/ipv4/tcp_minisocks.c:622
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
run_ksoftirqd+0x17/0x20 kernel/softirq.c:939
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x1cd237f1 -> 0x1cd237f2

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230717144445.653164-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
H A Dtcp_output.cdiff eba20811 Mon Jul 17 08:44:45 MDT 2023 Eric Dumazet <edumazet@google.com> tcp: annotate data-races around tcp_rsk(req)->ts_recent

TCP request sockets are lockless, tcp_rsk(req)->ts_recent
can change while being read by another cpu as syzbot noticed.

This is harmless, but we should annotate the known races.

Note that tcp_check_req() changes req->ts_recent a bit early,
we might change this in the future.

BUG: KCSAN: data-race in tcp_check_req / tcp_check_req

write to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 1:
tcp_check_req+0x694/0xc70 net/ipv4/tcp_minisocks.c:762
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
do_softirq+0x7e/0xb0 kernel/softirq.c:472
__local_bh_enable_ip+0x64/0x70 kernel/softirq.c:396
local_bh_enable+0x1f/0x20 include/linux/bottom_half.h:33
rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline]
__dev_queue_xmit+0xabb/0x1d10 net/core/dev.c:4271
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
neigh_hh_output include/net/neighbour.h:528 [inline]
neigh_output include/net/neighbour.h:542 [inline]
ip_finish_output2+0x700/0x840 net/ipv4/ip_output.c:229
ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:431
dst_output include/net/dst.h:458 [inline]
ip_local_out net/ipv4/ip_output.c:126 [inline]
__ip_queue_xmit+0xa4d/0xa70 net/ipv4/ip_output.c:533
ip_queue_xmit+0x38/0x40 net/ipv4/ip_output.c:547
__tcp_transmit_skb+0x1194/0x16e0 net/ipv4/tcp_output.c:1399
tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline]
tcp_write_xmit+0x13ff/0x2fd0 net/ipv4/tcp_output.c:2693
__tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:2877
tcp_push_pending_frames include/net/tcp.h:1952 [inline]
__tcp_sock_set_cork net/ipv4/tcp.c:3336 [inline]
tcp_sock_set_cork+0xe8/0x100 net/ipv4/tcp.c:3343
rds_tcp_xmit_path_complete+0x3b/0x40 net/rds/tcp_send.c:52
rds_send_xmit+0xf8d/0x1420 net/rds/send.c:422
rds_send_worker+0x42/0x1d0 net/rds/threads.c:200
process_one_work+0x3e6/0x750 kernel/workqueue.c:2408
worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 0:
tcp_check_req+0x32a/0xc70 net/ipv4/tcp_minisocks.c:622
tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071
ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:468 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
run_ksoftirqd+0x17/0x20 kernel/softirq.c:939
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x1cd237f1 -> 0x1cd237f2

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230717144445.653164-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
/linux-master/net/core/
H A Dsock.cdiff 9709020c Fri May 18 05:47:55 MDT 2018 Eric Dumazet <edumazet@google.com> sock_diag: fix use-after-free read in __sk_free

We must not call sock_diag_has_destroy_listeners(sk) on a socket
that has no reference on net structure.

BUG: KASAN: use-after-free in sock_diag_has_destroy_listeners include/linux/sock_diag.h:75 [inline]
BUG: KASAN: use-after-free in __sk_free+0x329/0x340 net/core/sock.c:1609
Read of size 8 at addr ffff88018a02e3a0 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.17.0-rc5+ #54
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
sock_diag_has_destroy_listeners include/linux/sock_diag.h:75 [inline]
__sk_free+0x329/0x340 net/core/sock.c:1609
sk_free+0x42/0x50 net/core/sock.c:1623
sock_put include/net/sock.h:1664 [inline]
reqsk_free include/net/request_sock.h:116 [inline]
reqsk_put include/net/request_sock.h:124 [inline]
inet_csk_reqsk_queue_drop_and_put net/ipv4/inet_connection_sock.c:672 [inline]
reqsk_timer_handler+0xe27/0x10e0 net/ipv4/inet_connection_sock.c:739
call_timer_fn+0x230/0x940 kernel/time/timer.c:1326
expire_timers kernel/time/timer.c:1363 [inline]
__run_timers+0x79e/0xc50 kernel/time/timer.c:1666
run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
__do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
invoke_softirq kernel/softirq.c:365 [inline]
irq_exit+0x1d1/0x200 kernel/softirq.c:405
exiting_irq arch/x86/include/asm/apic.h:525 [inline]
smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffff8801d9ae7c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1003b35cf8a RCX: 0000000000000000
RDX: 1ffffffff11a30d0 RSI: 0000000000000001 RDI: ffffffff88d18680
RBP: ffff8801d9ae7c38 R08: ffffed003b5e46c3 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8801d9ae7cf0 R14: ffffffff897bef20 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
default_idle+0xc2/0x440 arch/x86/kernel/process.c:354
arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:345
default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x395/0x560 kernel/sched/idle.c:262
cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368
start_secondary+0x426/0x5b0 arch/x86/kernel/smpboot.c:269
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

Allocated by task 4557:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
kmem_cache_zalloc include/linux/slab.h:691 [inline]
net_alloc net/core/net_namespace.c:383 [inline]
copy_net_ns+0x159/0x4c0 net/core/net_namespace.c:423
create_new_namespaces+0x69d/0x8f0 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206
ksys_unshare+0x708/0xf90 kernel/fork.c:2408
__do_sys_unshare kernel/fork.c:2476 [inline]
__se_sys_unshare kernel/fork.c:2474 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2474
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 69:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
net_free net/core/net_namespace.c:399 [inline]
net_drop_ns.part.14+0x11a/0x130 net/core/net_namespace.c:406
net_drop_ns net/core/net_namespace.c:405 [inline]
cleanup_net+0x6a1/0xb20 net/core/net_namespace.c:541
process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
kthread+0x345/0x410 kernel/kthread.c:240
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

The buggy address belongs to the object at ffff88018a02c140
which belongs to the cache net_namespace of size 8832
The buggy address is located 8800 bytes inside of
8832-byte region [ffff88018a02c140, ffff88018a02e3c0)
The buggy address belongs to the page:
page:ffffea0006280b00 count:1 mapcount:0 mapping:ffff88018a02c140 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff88018a02c140 0000000000000000 0000000100000001
raw: ffffea00062a1320 ffffea0006268020 ffff8801d9bdde40 0000000000000000
page dumped because: kasan: bad access detected

Fixes: b922622ec6ef ("sock_diag: don't broadcast kernel sockets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Craig Gallek <kraig@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
/linux-master/kernel/bpf/
H A Dverifier.cdiff be2ef816 Fri Nov 04 10:36:46 MDT 2022 Andrii Nakryiko <andrii@kernel.org> bpf: allow precision tracking for programs with subprogs

Stop forcing precise=true for SCALAR registers when BPF program has any
subprograms. Current restriction means that any BPF program, as soon as
it uses subprograms, will end up not getting any of the precision
tracking benefits in reduction of number of verified states.

This patch keeps the fallback mark_all_scalars_precise() behavior if
precise marking has to cross function frames. E.g., if subprogram
requires R1 (first input arg) to be marked precise, ideally we'd need to
backtrack to the parent function and keep marking R1 and its
dependencies as precise. But right now we give up and force all the
SCALARs in any of the current and parent states to be forced to
precise=true. We can lift that restriction in the future.

But this patch fixes two issues identified when trying to enable
precision tracking for subprogs.

First, prevent "escaping" from top-most state in a global subprog. While
with entry-level BPF program we never end up requesting precision for
R1-R5 registers, because R2-R5 are not initialized (and so not readable
in correct BPF program), and R1 is PTR_TO_CTX, not SCALAR, and so is
implicitly precise. With global subprogs, though, it's different, as
global subprog a) can have up to 5 SCALAR input arguments, which might
get marked as precise=true and b) it is validated in isolation from its
main entry BPF program. b) means that we can end up exhausting parent
state chain and still not mark all registers in reg_mask as precise,
which would lead to verifier bug warning.

To handle that, we need to consider two cases. First, if the very first
state is not immediately "checkpointed" (i.e., stored in state lookup
hashtable), it will get correct first_insn_idx and last_insn_idx
instruction set during state checkpointing. As such, this case is
already handled and __mark_chain_precision() already handles that by
just doing nothing when we reach to the very first parent state.
st->parent will be NULL and we'll just stop. Perhaps some extra check
for reg_mask and stack_mask is due here, but this patch doesn't address
that issue.

More problematic second case is when global function's initial state is
immediately checkpointed before we manage to process the very first
instruction. This is happening because when there is a call to global
subprog from the main program the very first subprog's instruction is
marked as pruning point, so before we manage to process first
instruction we have to check and checkpoint state. This patch adds
a special handling for such "empty" state, which is identified by having
st->last_insn_idx set to -1. In such case, we check that we are indeed
validating global subprog, and with some sanity checking we mark input
args as precise if requested.

Note that we also initialize state->first_insn_idx with correct start
insn_idx offset. For main program zero is correct value, but for any
subprog it's quite confusing to not have first_insn_idx set. This
doesn't have any functional impact, but helps with debugging and state
printing. We also explicitly initialize state->last_insns_idx instead of
relying on is_state_visited() to do this with env->prev_insns_idx, which
will be -1 on the very first instruction. This concludes necessary
changes to handle specifically global subprog's precision tracking.

Second identified problem was missed handling of BPF helper functions
that call into subprogs (e.g., bpf_loop and few others). From precision
tracking and backtracking logic's standpoint those are effectively calls
into subprogs and should be called as BPF_PSEUDO_CALL calls.

This patch takes the least intrusive way and just checks against a short
list of current BPF helpers that do call subprogs, encapsulated in
is_callback_calling_function() function. But to prevent accidentally
forgetting to add new BPF helpers to this "list", we also do a sanity
check in __check_func_call, which has to be called for each such special
BPF helper, to validate that BPF helper is indeed recognized as
callback-calling one. This should catch any missed checks in the future.
Adding some special flags to be added in function proto definitions
seemed like an overkill in this case.

With the above changes, it's possible to remove forceful setting of
reg->precise to true in __mark_reg_unknown, which turns on precision
tracking both inside subprogs and entry progs that have subprogs. No
warnings or errors were detected across all the selftests, but also when
validating with veristat against internal Meta BPF objects and Cilium
objects. Further, in some BPF programs there are noticeable reduction in
number of states and instructions validated due to more effective
precision tracking, especially benefiting syncookie test.

$ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/subprog-precise-results.csv | grep -v '+0'
File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF)
---------------------------------------- -------------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------
pyperf600_bpf_loop.bpf.linked1.o on_event 3966 3678 -288 (-7.26%) 306 276 -30 (-9.80%)
pyperf_global.bpf.linked1.o on_event 7563 7530 -33 (-0.44%) 520 517 -3 (-0.58%)
pyperf_subprogs.bpf.linked1.o on_event 36358 36934 +576 (+1.58%) 2499 2531 +32 (+1.28%)
setget_sockopt.bpf.linked1.o skops_sockopt 3965 4038 +73 (+1.84%) 343 347 +4 (+1.17%)
test_cls_redirect_subprogs.bpf.linked1.o cls_redirect 64965 64901 -64 (-0.10%) 4619 4612 -7 (-0.15%)
test_misc_tcp_hdr_options.bpf.linked1.o misc_estab 1491 1307 -184 (-12.34%) 110 100 -10 (-9.09%)
test_pkt_access.bpf.linked1.o test_pkt_access 354 349 -5 (-1.41%) 25 24 -1 (-4.00%)
test_sock_fields.bpf.linked1.o egress_read_sock_fields 435 375 -60 (-13.79%) 22 20 -2 (-9.09%)
test_sysctl_loop2.bpf.linked1.o sysctl_tcp_mem 1508 1501 -7 (-0.46%) 29 28 -1 (-3.45%)
test_tc_dtime.bpf.linked1.o egress_fwdns_prio100 468 435 -33 (-7.05%) 45 41 -4 (-8.89%)
test_tc_dtime.bpf.linked1.o ingress_fwdns_prio100 398 408 +10 (+2.51%) 42 39 -3 (-7.14%)
test_tc_dtime.bpf.linked1.o ingress_fwdns_prio101 1096 842 -254 (-23.18%) 97 73 -24 (-24.74%)
test_tcp_hdr_options.bpf.linked1.o estab 2758 2408 -350 (-12.69%) 208 181 -27 (-12.98%)
test_urandom_usdt.bpf.linked1.o urand_read_with_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o urand_read_without_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o urandlib_read_with_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o urandlib_read_without_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%)
test_xdp_noinline.bpf.linked1.o balancer_ingress_v6 4302 4294 -8 (-0.19%) 257 256 -1 (-0.39%)
xdp_synproxy_kern.bpf.linked1.o syncookie_tc 583722 405757 -177965 (-30.49%) 35846 25735 -10111 (-28.21%)
xdp_synproxy_kern.bpf.linked1.o syncookie_xdp 609123 479055 -130068 (-21.35%) 35452 29145 -6307 (-17.79%)
---------------------------------------- -------------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
/linux-master/mm/
H A Dslub.cdiff 2408c550 Tue Oct 16 02:24:44 MDT 2007 Satyam Sharma <satyam@infradead.org> {slub, slob}: use unlikely() for kfree(ZERO_OR_NULL_PTR) check

Considering kfree(NULL) would normally occur only in error paths and
kfree(ZERO_SIZE_PTR) is uncommon as well, so let's use unlikely() for the
condition check in SLUB's and SLOB's kfree() to optimize for the common
case. SLAB has this already.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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