linux.git/kernel/trace, branch v5.4-rc2 Linux kernel source tree Merge tag 'trace-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 2019-09-30T16:29:53+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-09-30T16:29:53+00:00 cf4f493b102399adea3cf65cdde7161c17fb605c Pull tracing fixes from Steven Rostedt: "A few more tracing fixes: - Fix a buffer overflow by checking nr_args correctly in probes - Fix a warning that is reported by clang - Fix a possible memory leak in error path of filter processing - Fix the selftest that checks for failures, but wasn't failing - Minor clean up on call site output of a memory trace event" * tag 'trace-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: selftests/ftrace: Fix same probe error test mm, tracing: Print symbol name for call_site in trace events tracing: Have error path in predicate_parse() free its allocated memory tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro tracing/probe: Fix to check the difference of nr_args before adding probe 
Pull tracing fixes from Steven Rostedt:
 "A few more tracing fixes:

   - Fix a buffer overflow by checking nr_args correctly in probes

   - Fix a warning that is reported by clang

   - Fix a possible memory leak in error path of filter processing

   - Fix the selftest that checks for failures, but wasn't failing

   - Minor clean up on call site output of a memory trace event"

* tag 'trace-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests/ftrace: Fix same probe error test
  mm, tracing: Print symbol name for call_site in trace events
  tracing: Have error path in predicate_parse() free its allocated memory
  tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro
  tracing/probe: Fix to check the difference of nr_args before adding probe
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-29T00:47:33+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-09-29T00:47:33+00:00 02dc96ef6c25f990452c114c59d75c368a1f4c8f Pull networking fixes from David Miller: 1) Sanity check URB networking device parameters to avoid divide by zero, from Oliver Neukum. 2) Disable global multicast filter in NCSI, otherwise LLDP and IPV6 don't work properly. Longer term this needs a better fix tho. From Vijay Khemka. 3) Small fixes to selftests (use ping when ping6 is not present, etc.) from David Ahern. 4) Bring back rt_uses_gateway member of struct rtable, it's semantics were not well understood and trying to remove it broke things. From David Ahern. 5) Move usbnet snaity checking, ignore endpoints with invalid wMaxPacketSize. From Bjørn Mork. 6) Missing Kconfig deps for sja1105 driver, from Mao Wenan. 7) Various small fixes to the mlx5 DR steering code, from Alaa Hleihel, Alex Vesker, and Yevgeny Kliteynik 8) Missing CAP_NET_RAW checks in various places, from Ori Nimron. 9) Fix crash when removing sch_cbs entry while offloading is enabled, from Vinicius Costa Gomes. 10) Signedness bug fixes, generally in looking at the result given by of_get_phy_mode() and friends. From Dan Crapenter. 11) Disable preemption around BPF_PROG_RUN() calls, from Eric Dumazet. 12) Don't create VRF ipv6 rules if ipv6 is disabled, from David Ahern. 13) Fix quantization code in tcp_bbr, from Kevin Yang. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (127 commits) net: tap: clean up an indentation issue nfp: abm: fix memory leak in nfp_abm_u32_knode_replace tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state sk_buff: drop all skb extensions on free and skb scrubbing tcp_bbr: fix quantization code to not raise cwnd if not probing bandwidth mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions Documentation: Clarify trap's description mlxsw: spectrum: Clear VLAN filters during port initialization net: ena: clean up indentation issue NFC: st95hf: clean up indentation issue net: phy: micrel: add Asym Pause workaround for KSZ9021 net: socionext: ave: Avoid using netdev_err() before calling register_netdev() ptp: correctly disable flags on old ioctls lib: dimlib: fix help text typos net: dsa: microchip: Always set regmap stride to 1 nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs net/sched: Set default of CONFIG_NET_TC_SKB_EXT to N vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled net: sched: sch_sfb: don't call qdisc_put() while holding tree lock ... 
Pull networking fixes from David Miller:

 1) Sanity check URB networking device parameters to avoid divide by
    zero, from Oliver Neukum.

 2) Disable global multicast filter in NCSI, otherwise LLDP and IPV6
    don't work properly. Longer term this needs a better fix tho. From
    Vijay Khemka.

 3) Small fixes to selftests (use ping when ping6 is not present, etc.)
    from David Ahern.

 4) Bring back rt_uses_gateway member of struct rtable, it's semantics
    were not well understood and trying to remove it broke things. From
    David Ahern.

 5) Move usbnet snaity checking, ignore endpoints with invalid
    wMaxPacketSize. From Bjørn Mork.

 6) Missing Kconfig deps for sja1105 driver, from Mao Wenan.

 7) Various small fixes to the mlx5 DR steering code, from Alaa Hleihel,
    Alex Vesker, and Yevgeny Kliteynik

 8) Missing CAP_NET_RAW checks in various places, from Ori Nimron.

 9) Fix crash when removing sch_cbs entry while offloading is enabled,
    from Vinicius Costa Gomes.

10) Signedness bug fixes, generally in looking at the result given by
    of_get_phy_mode() and friends. From Dan Crapenter.

11) Disable preemption around BPF_PROG_RUN() calls, from Eric Dumazet.

12) Don't create VRF ipv6 rules if ipv6 is disabled, from David Ahern.

13) Fix quantization code in tcp_bbr, from Kevin Yang.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (127 commits)
  net: tap: clean up an indentation issue
  nfp: abm: fix memory leak in nfp_abm_u32_knode_replace
  tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state
  sk_buff: drop all skb extensions on free and skb scrubbing
  tcp_bbr: fix quantization code to not raise cwnd if not probing bandwidth
  mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions
  Documentation: Clarify trap's description
  mlxsw: spectrum: Clear VLAN filters during port initialization
  net: ena: clean up indentation issue
  NFC: st95hf: clean up indentation issue
  net: phy: micrel: add Asym Pause workaround for KSZ9021
  net: socionext: ave: Avoid using netdev_err() before calling register_netdev()
  ptp: correctly disable flags on old ioctls
  lib: dimlib: fix help text typos
  net: dsa: microchip: Always set regmap stride to 1
  nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs
  nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs
  net/sched: Set default of CONFIG_NET_TC_SKB_EXT to N
  vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled
  net: sched: sch_sfb: don't call qdisc_put() while holding tree lock
  ...
tracing: Have error path in predicate_parse() free its allocated memory 2019-09-28T21:13:39+00:00 Navid Emamdoost navid.emamdoost@gmail.com 2019-09-20T22:57:59+00:00 96c5c6e6a5b6db592acae039fed54b5c8844cd35 In predicate_parse, there is an error path that is not going to out_free instead it returns directly which leads to a memory leak. Link: http://lkml.kernel.org/r/20190920225800.3870-1-navid.emamdoost@gmail.com Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
In predicate_parse, there is an error path that is not going to
out_free instead it returns directly which leads to a memory leak.

Link: http://lkml.kernel.org/r/20190920225800.3870-1-navid.emamdoost@gmail.com

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro 2019-09-28T21:13:39+00:00 Nathan Chancellor natechancellor@gmail.com 2019-09-26T16:22:59+00:00 968e5170939662341242812b9c82ef51cf140a33 After r372664 in clang, the IF_ASSIGN macro causes a couple hundred warnings along the lines of: kernel/trace/trace_output.c:1331:2: warning: converting the enum constant to a boolean [-Wint-in-bool-context] kernel/trace/trace.h:409:3: note: expanded from macro 'trace_assign_type' IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, ^ kernel/trace/trace.h:371:14: note: expanded from macro 'IF_ASSIGN' WARN_ON(id && (entry)->type != id); \ ^ 264 warnings generated. This warning can catch issues with constructs like: if (state == A || B) where the developer really meant: if (state == A || state == B) This is currently the only occurrence of the warning in the kernel tree across defconfig, allyesconfig, allmodconfig for arm32, arm64, and x86_64. Add the implicit '!= 0' to the WARN_ON statement to fix the warnings and find potential issues in the future. Link: https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd962f070b Link: https://github.com/ClangBuiltLinux/linux/issues/686 Link: http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
After r372664 in clang, the IF_ASSIGN macro causes a couple hundred
warnings along the lines of:

kernel/trace/trace_output.c:1331:2: warning: converting the enum
constant to a boolean [-Wint-in-bool-context]
kernel/trace/trace.h:409:3: note: expanded from macro
'trace_assign_type'
                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,
                ^
kernel/trace/trace.h:371:14: note: expanded from macro 'IF_ASSIGN'
                WARN_ON(id && (entry)->type != id);     \
                           ^
264 warnings generated.

This warning can catch issues with constructs like:

    if (state == A || B)

where the developer really meant:

    if (state == A || state == B)

This is currently the only occurrence of the warning in the kernel
tree across defconfig, allyesconfig, allmodconfig for arm32, arm64,
and x86_64. Add the implicit '!= 0' to the WARN_ON statement to fix
the warnings and find potential issues in the future.

Link: https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd962f070b
Link: https://github.com/ClangBuiltLinux/linux/issues/686
Link: http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
tracing/probe: Fix to check the difference of nr_args before adding probe 2019-09-28T21:07:53+00:00 Masami Hiramatsu mhiramat@kernel.org 2019-09-28T09:53:29+00:00 d2aea95a1a4d195d939d16303700921be318a2b9 Steven reported that a test triggered: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 Call Trace: dump_stack+0x7c/0xc0 ? trace_kprobe_create+0xa9e/0xe40 print_address_description+0x6c/0x332 ? trace_kprobe_create+0xa9e/0xe40 ? trace_kprobe_create+0xa9e/0xe40 __kasan_report.cold.6+0x1a/0x3b ? trace_kprobe_create+0xa9e/0xe40 kasan_report+0xe/0x12 trace_kprobe_create+0xa9e/0xe40 ? print_kprobe_event+0x280/0x280 ? match_held_lock+0x1b/0x240 ? find_held_lock+0xac/0xd0 ? fs_reclaim_release.part.112+0x5/0x20 ? lock_downgrade+0x350/0x350 ? kasan_unpoison_shadow+0x30/0x40 ? __kasan_kmalloc.constprop.6+0xc1/0xd0 ? trace_kprobe_create+0xe40/0xe40 ? trace_kprobe_create+0xe40/0xe40 create_or_delete_trace_kprobe+0x2e/0x60 trace_run_command+0xc3/0xe0 ? trace_panic_handler+0x20/0x20 ? kasan_unpoison_shadow+0x30/0x40 trace_parse_run_command+0xdc/0x163 vfs_write+0xe1/0x240 ksys_write+0xba/0x150 ? __ia32_sys_read+0x50/0x50 ? tracer_hardirqs_on+0x61/0x180 ? trace_hardirqs_off_caller+0x43/0x110 ? mark_held_locks+0x29/0xa0 ? do_syscall_64+0x14/0x260 do_syscall_64+0x68/0x260 Fix to check the difference of nr_args before adding probe on existing probes. This also may set the error log index bigger than the number of command parameters. In that case it sets the error position is next to the last parameter. Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2 Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support") Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
Steven reported that a test triggered:

==================================================================
 BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40
 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798

 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 Call Trace:
  dump_stack+0x7c/0xc0
  ? trace_kprobe_create+0xa9e/0xe40
  print_address_description+0x6c/0x332
  ? trace_kprobe_create+0xa9e/0xe40
  ? trace_kprobe_create+0xa9e/0xe40
  __kasan_report.cold.6+0x1a/0x3b
  ? trace_kprobe_create+0xa9e/0xe40
  kasan_report+0xe/0x12
  trace_kprobe_create+0xa9e/0xe40
  ? print_kprobe_event+0x280/0x280
  ? match_held_lock+0x1b/0x240
  ? find_held_lock+0xac/0xd0
  ? fs_reclaim_release.part.112+0x5/0x20
  ? lock_downgrade+0x350/0x350
  ? kasan_unpoison_shadow+0x30/0x40
  ? __kasan_kmalloc.constprop.6+0xc1/0xd0
  ? trace_kprobe_create+0xe40/0xe40
  ? trace_kprobe_create+0xe40/0xe40
  create_or_delete_trace_kprobe+0x2e/0x60
  trace_run_command+0xc3/0xe0
  ? trace_panic_handler+0x20/0x20
  ? kasan_unpoison_shadow+0x30/0x40
  trace_parse_run_command+0xdc/0x163
  vfs_write+0xe1/0x240
  ksys_write+0xba/0x150
  ? __ia32_sys_read+0x50/0x50
  ? tracer_hardirqs_on+0x61/0x180
  ? trace_hardirqs_off_caller+0x43/0x110
  ? mark_held_locks+0x29/0xa0
  ? do_syscall_64+0x14/0x260
  do_syscall_64+0x68/0x260

Fix to check the difference of nr_args before adding probe
on existing probes. This also may set the error log index
bigger than the number of command parameters. In that case
it sets the error position is next to the last parameter.

Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2

Fixes: ca89bc071d5e ("tracing/kprobe: Add multi-probe per event support")
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28T15:14:15+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-09-28T15:14:15+00:00 aefcf2f4b58155d27340ba5f9ddbe9513da8286d Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ... 
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
bpf: Fix bpf_event_output re-entry issue 2019-09-27T09:24:29+00:00 Allan Zhang allanzhang@google.com 2019-09-25T23:43:12+00:00 768fb61fcc13b2acaca758275d54c09a65e2968b BPF_PROG_TYPE_SOCK_OPS program can reenter bpf_event_output because it can be called from atomic and non-atomic contexts since we don't have bpf_prog_active to prevent it happen. This patch enables 3 levels of nesting to support normal, irq and nmi context. We can easily reproduce the issue by running netperf crr mode with 100 flows and 10 threads from netperf client side. Here is the whole stack dump: [ 515.228898] WARNING: CPU: 20 PID: 14686 at kernel/trace/bpf_trace.c:549 bpf_event_output+0x1f9/0x220 [ 515.228903] CPU: 20 PID: 14686 Comm: tcp_crr Tainted: G W 4.15.0-smp-fixpanic #44 [ 515.228904] Hardware name: Intel TBG,ICH10/Ikaria_QC_1b, BIOS 1.22.0 06/04/2018 [ 515.228905] RIP: 0010:bpf_event_output+0x1f9/0x220 [ 515.228906] RSP: 0018:ffff9a57ffc03938 EFLAGS: 00010246 [ 515.228907] RAX: 0000000000000012 RBX: 0000000000000001 RCX: 0000000000000000 [ 515.228907] RDX: 0000000000000000 RSI: 0000000000000096 RDI: ffffffff836b0f80 [ 515.228908] RBP: ffff9a57ffc039c8 R08: 0000000000000004 R09: 0000000000000012 [ 515.228908] R10: ffff9a57ffc1de40 R11: 0000000000000000 R12: 0000000000000002 [ 515.228909] R13: ffff9a57e13bae00 R14: 00000000ffffffff R15: ffff9a57ffc1e2c0 [ 515.228910] FS: 00007f5a3e6ec700(0000) GS:ffff9a57ffc00000(0000) knlGS:0000000000000000 [ 515.228910] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 515.228911] CR2: 0000537082664fff CR3: 000000061fed6002 CR4: 00000000000226f0 [ 515.228911] Call Trace: [ 515.228913] <IRQ> [ 515.228919] [<ffffffff82c6c6cb>] bpf_sockopt_event_output+0x3b/0x50 [ 515.228923] [<ffffffff8265daee>] ? bpf_ktime_get_ns+0xe/0x10 [ 515.228927] [<ffffffff8266fda5>] ? __cgroup_bpf_run_filter_sock_ops+0x85/0x100 [ 515.228930] [<ffffffff82cf90a5>] ? tcp_init_transfer+0x125/0x150 [ 515.228933] [<ffffffff82cf9159>] ? tcp_finish_connect+0x89/0x110 [ 515.228936] [<ffffffff82cf98e4>] ? tcp_rcv_state_process+0x704/0x1010 [ 515.228939] [<ffffffff82c6e263>] ? sk_filter_trim_cap+0x53/0x2a0 [ 515.228942] [<ffffffff82d90d1f>] ? tcp_v6_inbound_md5_hash+0x6f/0x1d0 [ 515.228945] [<ffffffff82d92160>] ? tcp_v6_do_rcv+0x1c0/0x460 [ 515.228947] [<ffffffff82d93558>] ? tcp_v6_rcv+0x9f8/0xb30 [ 515.228951] [<ffffffff82d737c0>] ? ip6_route_input+0x190/0x220 [ 515.228955] [<ffffffff82d5f7ad>] ? ip6_protocol_deliver_rcu+0x6d/0x450 [ 515.228958] [<ffffffff82d60246>] ? ip6_rcv_finish+0xb6/0x170 [ 515.228961] [<ffffffff82d5fb90>] ? ip6_protocol_deliver_rcu+0x450/0x450 [ 515.228963] [<ffffffff82d60361>] ? ipv6_rcv+0x61/0xe0 [ 515.228966] [<ffffffff82d60190>] ? ipv6_list_rcv+0x330/0x330 [ 515.228969] [<ffffffff82c4976b>] ? __netif_receive_skb_one_core+0x5b/0xa0 [ 515.228972] [<ffffffff82c497d1>] ? __netif_receive_skb+0x21/0x70 [ 515.228975] [<ffffffff82c4a8d2>] ? process_backlog+0xb2/0x150 [ 515.228978] [<ffffffff82c4aadf>] ? net_rx_action+0x16f/0x410 [ 515.228982] [<ffffffff830000dd>] ? __do_softirq+0xdd/0x305 [ 515.228986] [<ffffffff8252cfdc>] ? irq_exit+0x9c/0xb0 [ 515.228989] [<ffffffff82e02de5>] ? smp_call_function_single_interrupt+0x65/0x120 [ 515.228991] [<ffffffff82e020e1>] ? call_function_single_interrupt+0x81/0x90 [ 515.228992] </IRQ> [ 515.228996] [<ffffffff82a11ff0>] ? io_serial_in+0x20/0x20 [ 515.229000] [<ffffffff8259c040>] ? console_unlock+0x230/0x490 [ 515.229003] [<ffffffff8259cbaa>] ? vprintk_emit+0x26a/0x2a0 [ 515.229006] [<ffffffff8259cbff>] ? vprintk_default+0x1f/0x30 [ 515.229008] [<ffffffff8259d9f5>] ? vprintk_func+0x35/0x70 [ 515.229011] [<ffffffff8259d4bb>] ? printk+0x50/0x66 [ 515.229013] [<ffffffff82637637>] ? bpf_event_output+0xb7/0x220 [ 515.229016] [<ffffffff82c6c6cb>] ? bpf_sockopt_event_output+0x3b/0x50 [ 515.229019] [<ffffffff8265daee>] ? bpf_ktime_get_ns+0xe/0x10 [ 515.229023] [<ffffffff82c29e87>] ? release_sock+0x97/0xb0 [ 515.229026] [<ffffffff82ce9d6a>] ? tcp_recvmsg+0x31a/0xda0 [ 515.229029] [<ffffffff8266fda5>] ? __cgroup_bpf_run_filter_sock_ops+0x85/0x100 [ 515.229032] [<ffffffff82ce77c1>] ? tcp_set_state+0x191/0x1b0 [ 515.229035] [<ffffffff82ced10e>] ? tcp_disconnect+0x2e/0x600 [ 515.229038] [<ffffffff82cecbbb>] ? tcp_close+0x3eb/0x460 [ 515.229040] [<ffffffff82d21082>] ? inet_release+0x42/0x70 [ 515.229043] [<ffffffff82d58809>] ? inet6_release+0x39/0x50 [ 515.229046] [<ffffffff82c1f32d>] ? __sock_release+0x4d/0xd0 [ 515.229049] [<ffffffff82c1f3e5>] ? sock_close+0x15/0x20 [ 515.229052] [<ffffffff8273b517>] ? __fput+0xe7/0x1f0 [ 515.229055] [<ffffffff8273b66e>] ? ____fput+0xe/0x10 [ 515.229058] [<ffffffff82547bf2>] ? task_work_run+0x82/0xb0 [ 515.229061] [<ffffffff824086df>] ? exit_to_usermode_loop+0x7e/0x11f [ 515.229064] [<ffffffff82408171>] ? do_syscall_64+0x111/0x130 [ 515.229067] [<ffffffff82e0007c>] ? entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: a5a3a828cd00 ("bpf: add perf event notificaton support for sock_ops") Signed-off-by: Allan Zhang <allanzhang@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20190925234312.94063-2-allanzhang@google.com 
BPF_PROG_TYPE_SOCK_OPS program can reenter bpf_event_output because it
can be called from atomic and non-atomic contexts since we don't have
bpf_prog_active to prevent it happen.

This patch enables 3 levels of nesting to support normal, irq and nmi
context.

We can easily reproduce the issue by running netperf crr mode with 100
flows and 10 threads from netperf client side.

Here is the whole stack dump:

[  515.228898] WARNING: CPU: 20 PID: 14686 at kernel/trace/bpf_trace.c:549 bpf_event_output+0x1f9/0x220
[  515.228903] CPU: 20 PID: 14686 Comm: tcp_crr Tainted: G        W        4.15.0-smp-fixpanic #44
[  515.228904] Hardware name: Intel TBG,ICH10/Ikaria_QC_1b, BIOS 1.22.0 06/04/2018
[  515.228905] RIP: 0010:bpf_event_output+0x1f9/0x220
[  515.228906] RSP: 0018:ffff9a57ffc03938 EFLAGS: 00010246
[  515.228907] RAX: 0000000000000012 RBX: 0000000000000001 RCX: 0000000000000000
[  515.228907] RDX: 0000000000000000 RSI: 0000000000000096 RDI: ffffffff836b0f80
[  515.228908] RBP: ffff9a57ffc039c8 R08: 0000000000000004 R09: 0000000000000012
[  515.228908] R10: ffff9a57ffc1de40 R11: 0000000000000000 R12: 0000000000000002
[  515.228909] R13: ffff9a57e13bae00 R14: 00000000ffffffff R15: ffff9a57ffc1e2c0
[  515.228910] FS:  00007f5a3e6ec700(0000) GS:ffff9a57ffc00000(0000) knlGS:0000000000000000
[  515.228910] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  515.228911] CR2: 0000537082664fff CR3: 000000061fed6002 CR4: 00000000000226f0
[  515.228911] Call Trace:
[  515.228913]  <IRQ>
[  515.228919]  [<ffffffff82c6c6cb>] bpf_sockopt_event_output+0x3b/0x50
[  515.228923]  [<ffffffff8265daee>] ? bpf_ktime_get_ns+0xe/0x10
[  515.228927]  [<ffffffff8266fda5>] ? __cgroup_bpf_run_filter_sock_ops+0x85/0x100
[  515.228930]  [<ffffffff82cf90a5>] ? tcp_init_transfer+0x125/0x150
[  515.228933]  [<ffffffff82cf9159>] ? tcp_finish_connect+0x89/0x110
[  515.228936]  [<ffffffff82cf98e4>] ? tcp_rcv_state_process+0x704/0x1010
[  515.228939]  [<ffffffff82c6e263>] ? sk_filter_trim_cap+0x53/0x2a0
[  515.228942]  [<ffffffff82d90d1f>] ? tcp_v6_inbound_md5_hash+0x6f/0x1d0
[  515.228945]  [<ffffffff82d92160>] ? tcp_v6_do_rcv+0x1c0/0x460
[  515.228947]  [<ffffffff82d93558>] ? tcp_v6_rcv+0x9f8/0xb30
[  515.228951]  [<ffffffff82d737c0>] ? ip6_route_input+0x190/0x220
[  515.228955]  [<ffffffff82d5f7ad>] ? ip6_protocol_deliver_rcu+0x6d/0x450
[  515.228958]  [<ffffffff82d60246>] ? ip6_rcv_finish+0xb6/0x170
[  515.228961]  [<ffffffff82d5fb90>] ? ip6_protocol_deliver_rcu+0x450/0x450
[  515.228963]  [<ffffffff82d60361>] ? ipv6_rcv+0x61/0xe0
[  515.228966]  [<ffffffff82d60190>] ? ipv6_list_rcv+0x330/0x330
[  515.228969]  [<ffffffff82c4976b>] ? __netif_receive_skb_one_core+0x5b/0xa0
[  515.228972]  [<ffffffff82c497d1>] ? __netif_receive_skb+0x21/0x70
[  515.228975]  [<ffffffff82c4a8d2>] ? process_backlog+0xb2/0x150
[  515.228978]  [<ffffffff82c4aadf>] ? net_rx_action+0x16f/0x410
[  515.228982]  [<ffffffff830000dd>] ? __do_softirq+0xdd/0x305
[  515.228986]  [<ffffffff8252cfdc>] ? irq_exit+0x9c/0xb0
[  515.228989]  [<ffffffff82e02de5>] ? smp_call_function_single_interrupt+0x65/0x120
[  515.228991]  [<ffffffff82e020e1>] ? call_function_single_interrupt+0x81/0x90
[  515.228992]  </IRQ>
[  515.228996]  [<ffffffff82a11ff0>] ? io_serial_in+0x20/0x20
[  515.229000]  [<ffffffff8259c040>] ? console_unlock+0x230/0x490
[  515.229003]  [<ffffffff8259cbaa>] ? vprintk_emit+0x26a/0x2a0
[  515.229006]  [<ffffffff8259cbff>] ? vprintk_default+0x1f/0x30
[  515.229008]  [<ffffffff8259d9f5>] ? vprintk_func+0x35/0x70
[  515.229011]  [<ffffffff8259d4bb>] ? printk+0x50/0x66
[  515.229013]  [<ffffffff82637637>] ? bpf_event_output+0xb7/0x220
[  515.229016]  [<ffffffff82c6c6cb>] ? bpf_sockopt_event_output+0x3b/0x50
[  515.229019]  [<ffffffff8265daee>] ? bpf_ktime_get_ns+0xe/0x10
[  515.229023]  [<ffffffff82c29e87>] ? release_sock+0x97/0xb0
[  515.229026]  [<ffffffff82ce9d6a>] ? tcp_recvmsg+0x31a/0xda0
[  515.229029]  [<ffffffff8266fda5>] ? __cgroup_bpf_run_filter_sock_ops+0x85/0x100
[  515.229032]  [<ffffffff82ce77c1>] ? tcp_set_state+0x191/0x1b0
[  515.229035]  [<ffffffff82ced10e>] ? tcp_disconnect+0x2e/0x600
[  515.229038]  [<ffffffff82cecbbb>] ? tcp_close+0x3eb/0x460
[  515.229040]  [<ffffffff82d21082>] ? inet_release+0x42/0x70
[  515.229043]  [<ffffffff82d58809>] ? inet6_release+0x39/0x50
[  515.229046]  [<ffffffff82c1f32d>] ? __sock_release+0x4d/0xd0
[  515.229049]  [<ffffffff82c1f3e5>] ? sock_close+0x15/0x20
[  515.229052]  [<ffffffff8273b517>] ? __fput+0xe7/0x1f0
[  515.229055]  [<ffffffff8273b66e>] ? ____fput+0xe/0x10
[  515.229058]  [<ffffffff82547bf2>] ? task_work_run+0x82/0xb0
[  515.229061]  [<ffffffff824086df>] ? exit_to_usermode_loop+0x7e/0x11f
[  515.229064]  [<ffffffff82408171>] ? do_syscall_64+0x111/0x130
[  515.229067]  [<ffffffff82e0007c>] ? entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: a5a3a828cd00 ("bpf: add perf event notificaton support for sock_ops")
Signed-off-by: Allan Zhang <allanzhang@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20190925234312.94063-2-allanzhang@google.com
Merge tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 2019-09-26T20:07:38+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-09-26T20:07:38+00:00 7897c04ad09f815aea1f2dbb05825887d4494a74 Pull tracing fix from Steven Rostedt: "Srikar Dronamraju fixed a bug in the newmulti probe code" * tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/probe: Fix same probe event argument matching 
Pull tracing fix from Steven Rostedt:
 "Srikar Dronamraju fixed a bug in the newmulti probe code"

* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Fix same probe event argument matching
tracing/probe: Fix same probe event argument matching 2019-09-25T10:34:06+00:00 Srikar Dronamraju srikar@linux.vnet.ibm.com 2019-09-24T11:49:06+00:00 f8d7ab2bded897607bff6324d5c6ea6b4aecca0c Commit fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event") tries to reject a event which matches an already existing probe. However it currently continues to match arguments and rejects adding a probe even when the arguments don't match. Fix this by only rejecting a probe if and only if all the arguments match. Link: http://lkml.kernel.org/r/20190924114906.14038-1-srikar@linux.vnet.ibm.com Fixes: fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
Commit fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event")
tries to reject a event which matches an already existing probe.

However it currently continues to match arguments and rejects adding a
probe even when the arguments don't match. Fix this by only rejecting a
probe if and only if all the arguments match.

Link: http://lkml.kernel.org/r/20190924114906.14038-1-srikar@linux.vnet.ibm.com

Fixes: fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2019-09-20T18:48:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-09-20T18:48:06+00:00 45824fc0da6e46cc5d563105e1eaaf3098a686f9 Pull powerpc updates from Michael Ellerman: "This is a bit late, partly due to me travelling, and partly due to a power outage knocking out some of my test systems *while* I was travelling. - Initial support for running on a system with an Ultravisor, which is software that runs below the hypervisor and protects guests against some attacks by the hypervisor. - Support for building the kernel to run as a "Secure Virtual Machine", ie. as a guest capable of running on a system with an Ultravisor. - Some changes to our DMA code on bare metal, to allow devices with medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space. - Support for firmware assisted crash dumps on bare metal (powernv). - Two series fixing bugs in and refactoring our PCI EEH code. - A large series refactoring our exception entry code to use gas macros, both to make it more readable and also enable some future optimisations. As well as many cleanups and other minor features & fixups. Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar, Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde" * tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits) powerpc/mm/mce: Keep irqs disabled during lockless page table walk powerpc: Use ftrace_graph_ret_addr() when unwinding powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR ftrace: Look up the address of return_to_handler() using helpers powerpc: dump kernel log before carrying out fadump or kdump docs: powerpc: Add missing documentation reference powerpc/xmon: Fix output of XIVE IPI powerpc/xmon: Improve output of XIVE interrupts powerpc/mm/radix: remove useless kernel messages powerpc/fadump: support holes in kernel boot memory area powerpc/fadump: remove RMA_START and RMA_END macros powerpc/fadump: update documentation about option to release opalcore powerpc/fadump: consider f/w load area powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel powerpc/fadump: improve how crashed kernel's memory is reserved powerpc/fadump: consider reserved ranges while releasing memory powerpc/fadump: make crash memory ranges array allocation generic ... 
Pull powerpc updates from Michael Ellerman:
 "This is a bit late, partly due to me travelling, and partly due to a
  power outage knocking out some of my test systems *while* I was
  travelling.

   - Initial support for running on a system with an Ultravisor, which
     is software that runs below the hypervisor and protects guests
     against some attacks by the hypervisor.

   - Support for building the kernel to run as a "Secure Virtual
     Machine", ie. as a guest capable of running on a system with an
     Ultravisor.

   - Some changes to our DMA code on bare metal, to allow devices with
     medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
     DMA space.

   - Support for firmware assisted crash dumps on bare metal (powernv).

   - Two series fixing bugs in and refactoring our PCI EEH code.

   - A large series refactoring our exception entry code to use gas
     macros, both to make it more readable and also enable some future
     optimisations.

  As well as many cleanups and other minor features & fixups.

  Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
  Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
  JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
  Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
  Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
  Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
  Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
  Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
  Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
  Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
  Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
  Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
  Lendacky, Vasant Hegde"

* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
  powerpc/mm/mce: Keep irqs disabled during lockless page table walk
  powerpc: Use ftrace_graph_ret_addr() when unwinding
  powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  ftrace: Look up the address of return_to_handler() using helpers
  powerpc: dump kernel log before carrying out fadump or kdump
  docs: powerpc: Add missing documentation reference
  powerpc/xmon: Fix output of XIVE IPI
  powerpc/xmon: Improve output of XIVE interrupts
  powerpc/mm/radix: remove useless kernel messages
  powerpc/fadump: support holes in kernel boot memory area
  powerpc/fadump: remove RMA_START and RMA_END macros
  powerpc/fadump: update documentation about option to release opalcore
  powerpc/fadump: consider f/w load area
  powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
  powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
  powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
  powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
  powerpc/fadump: improve how crashed kernel's memory is reserved
  powerpc/fadump: consider reserved ranges while releasing memory
  powerpc/fadump: make crash memory ranges array allocation generic
  ...