[OE-core] [PATCH] lttng-modules: Check the pid_ns before using it because it may be NULL
Jonathan Rajotte-Julien
jonathan.rajotte-julien at efficios.com
Thu Feb 20 14:47:35 UTC 2020
Hi,
Can we get more info on the kernel version and config?
Did you submit this on our mailing list?(lttng-dev). If not I would highly recommend that you do so in the future so we can eliminate *custom* patches and get to the bottom of the issue at hand so that the whole community benefit from it.
Cheers
----- Li Zhou <li.zhou at windriver.com> wrote:
> Check the pid_ns before using it because it may be NULL to fix below
> issue:
> <1>[ 22.637196] Unable to handle kernel NULL pointer dereference at
> virtual address 0000000000000080
> <1>[ 22.645982] Mem abort info:
> <1>[ 22.648769] ESR = 0x96000007
> <1>[ 22.651817] Exception class = DABT (current EL), IL = 32 bits
> <1>[ 22.657730] SET = 0, FnV = 0
> <1>[ 22.660777] EA = 0, S1PTW = 0
> <1>[ 22.663910] Data abort info:
> <1>[ 22.666784] ISV = 0, ISS = 0x00000007
> <1>[ 22.670611] CM = 0, WnR = 0
> <1>[ 22.673574] user pgtable: 4k pages, 39-bit VAs, pgdp =
> 0000000012378f78
> <1>[ 22.680180] [0000000000000080] pgd=000000007f023003,
> pud=000000007f023003, pmd=000000007f01f003, pte=0000000000000000
> <0>[ 22.690794] Internal error: Oops: 96000007 [#1] PREEMPT SMP
> <4>[ 22.690797] Modules linked in: adkNetD ncp
> lttng_ring_buffer_client_overwrite(C)
> lttng_ring_buffer_metadata_client(C) lttng_ring_buffer_client_discard(C)
> lttng_ring_buffer_client_mmap_overwrite(C)
> lttng_ring_buffer_client_mmap_discard(C)
> lttng_ring_buffer_metadata_mmap_client(C) lttng_probe_signal(C)
> lttng_probe_printk(C) lttng_probe_sched(C) lttng_probe_irq(C)
> lttng_tracer(C) lttng_statedump(C) lttng_ftrace(C)
> lttng_lib_ring_buffer(C) lttng_clock_plugin_arm_cntpct(C) lttng_clock(C)
> <0>[ 22.690823] Process lttng-sessiond (pid: 3093, stack limit =
> 0x000000005d27910f)
> <4>[ 22.690828] CPU: 1 PID: 3093 Comm: lttng-sessiond Tainted: G C
> 4.18.37-rt820-custom #1
> <4>[ 22.690830] Hardware name: DUS33 (CPM2-20) (DT)
> <4>[ 22.690833] pstate: 60000005 (nZCv daif -PAN -UAO)
> <4>[ 22.690845] pc : do_lttng_statedump+0xcc/0x8a8 [lttng_statedump]
> <4>[ 22.690849] lr : do_lttng_statedump+0xc4/0x8a8 [lttng_statedump]
> <4>[ 22.690851] sp : ffffffc07fe57ad0
> <4>[ 22.690852] x29: ffffffc07fe57ad0 x28: ffffffc008ae2700
> <4>[ 22.690856] x27: ffffff8000724000 x26: 0000000000000001
> <4>[ 22.690859] x25: ffffff80089c9620 x24: 0000000000000000
> <4>[ 22.690862] x23: ffffffc008ae2e10 x22: ffffff80089d3380
> <4>[ 22.690865] x21: ffffffc07f450000 x20: ffffffc008ae2700
> <4>[ 22.690869] x19: 0000000000000007 x18: 00000000fffffffe
> <4>[ 22.690871] x17: 0000000000000000 x16: ffffff800824b980
> <4>[ 22.690874] x15: 0000000000000000 x14: 736162203b656e6f
> <4>[ 22.690877] x13: 6e203d20676e6964 x12: 0000000000000000
> <4>[ 22.690880] x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f
> <4>[ 22.690882] x9 : 3c1f647968721eff x8 : ffffffc0877504c8
> <4>[ 22.690886] x7 : 09093a7c093a7c08 x6 : ffffff8010c4b317
> <4>[ 22.690888] x5 : 0000000000000000 x4 : 00000040a7575000
> <4>[ 22.690891] x3 : ffffffc008ae2e28 x2 : 0000000000000000
> <4>[ 22.690894] x1 : 0000000000000000 x0 : 0000000000000000
> <4>[ 22.690896] Call trace:
> <4>[ 22.690902] do_lttng_statedump+0xcc/0x8a8 [lttng_statedump]
> <4>[ 22.690905] lttng_statedump_start+0x20/0x30 [lttng_statedump]
> <4>[ 22.690981] lttng_session_enable+0xf0/0x120 [lttng_tracer]
> <4>[ 22.691018] lttng_session_ioctl+0x22c/0x328 [lttng_tracer]
> <4>[ 22.691026] compat_sys_ioctl+0x110/0x778
>
> Signed-off-by: Li Zhou <li.zhou at windriver.com>
> ---
> ...es-Check-the-pid_ns-before-using-it-becau.patch | 86 ++++++++++++++++++++++
> meta/recipes-kernel/lttng/lttng-modules_2.11.1.bb | 2 +
> 2 files changed, 88 insertions(+)
> create mode 100644 meta/recipes-kernel/lttng/lttng-modules/0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch
>
> diff --git a/meta/recipes-kernel/lttng/lttng-modules/0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch b/meta/recipes-kernel/lttng/lttng-modules/0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch
> new file mode 100644
> index 0000000..5306c79
> --- /dev/null
> +++ b/meta/recipes-kernel/lttng/lttng-modules/0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch
> @@ -0,0 +1,86 @@
> +From 0c0072e005ce9d591518d1819a39264859132561 Mon Sep 17 00:00:00 2001
> +From: Li Zhou <li.zhou at windriver.com>
> +Date: Wed, 19 Feb 2020 11:14:38 +0800
> +Subject: [PATCH] lttng-modules: Check the pid_ns before using it because it
> + may be NULL
> +
> +<1>[ 22.637196] Unable to handle kernel NULL pointer dereference at
> +virtual address 0000000000000080
> +<1>[ 22.645982] Mem abort info:
> +<1>[ 22.648769] ESR = 0x96000007
> +<1>[ 22.651817] Exception class = DABT (current EL), IL = 32 bits
> +<1>[ 22.657730] SET = 0, FnV = 0
> +<1>[ 22.660777] EA = 0, S1PTW = 0
> +<1>[ 22.663910] Data abort info:
> +<1>[ 22.666784] ISV = 0, ISS = 0x00000007
> +<1>[ 22.670611] CM = 0, WnR = 0
> +<1>[ 22.673574] user pgtable: 4k pages, 39-bit VAs, pgdp =
> +0000000012378f78
> +<1>[ 22.680180] [0000000000000080] pgd=000000007f023003,
> +pud=000000007f023003, pmd=000000007f01f003, pte=0000000000000000
> +<0>[ 22.690794] Internal error: Oops: 96000007 [#1] PREEMPT SMP
> +<4>[ 22.690797] Modules linked in: adkNetD ncp
> +lttng_ring_buffer_client_overwrite(C)
> +lttng_ring_buffer_metadata_client(C) lttng_ring_buffer_client_discard(C)
> +lttng_ring_buffer_client_mmap_overwrite(C)
> +lttng_ring_buffer_client_mmap_discard(C)
> +lttng_ring_buffer_metadata_mmap_client(C) lttng_probe_signal(C)
> +lttng_probe_printk(C) lttng_probe_sched(C) lttng_probe_irq(C)
> +lttng_tracer(C) lttng_statedump(C) lttng_ftrace(C)
> +lttng_lib_ring_buffer(C) lttng_clock_plugin_arm_cntpct(C) lttng_clock(C)
> +<0>[ 22.690823] Process lttng-sessiond (pid: 3093, stack limit =
> +0x000000005d27910f)
> +<4>[ 22.690828] CPU: 1 PID: 3093 Comm: lttng-sessiond Tainted: G C
> +4.18.37-rt820-custom #1
> +<4>[ 22.690830] Hardware name: DUS33 (CPM2-20) (DT)
> +<4>[ 22.690833] pstate: 60000005 (nZCv daif -PAN -UAO)
> +<4>[ 22.690845] pc : do_lttng_statedump+0xcc/0x8a8 [lttng_statedump]
> +<4>[ 22.690849] lr : do_lttng_statedump+0xc4/0x8a8 [lttng_statedump]
> +<4>[ 22.690851] sp : ffffffc07fe57ad0
> +<4>[ 22.690852] x29: ffffffc07fe57ad0 x28: ffffffc008ae2700
> +<4>[ 22.690856] x27: ffffff8000724000 x26: 0000000000000001
> +<4>[ 22.690859] x25: ffffff80089c9620 x24: 0000000000000000
> +<4>[ 22.690862] x23: ffffffc008ae2e10 x22: ffffff80089d3380
> +<4>[ 22.690865] x21: ffffffc07f450000 x20: ffffffc008ae2700
> +<4>[ 22.690869] x19: 0000000000000007 x18: 00000000fffffffe
> +<4>[ 22.690871] x17: 0000000000000000 x16: ffffff800824b980
> +<4>[ 22.690874] x15: 0000000000000000 x14: 736162203b656e6f
> +<4>[ 22.690877] x13: 6e203d20676e6964 x12: 0000000000000000
> +<4>[ 22.690880] x11: 0101010101010101 x10: 7f7f7f7f7f7f7f7f
> +<4>[ 22.690882] x9 : 3c1f647968721eff x8 : ffffffc0877504c8
> +<4>[ 22.690886] x7 : 09093a7c093a7c08 x6 : ffffff8010c4b317
> +<4>[ 22.690888] x5 : 0000000000000000 x4 : 00000040a7575000
> +<4>[ 22.690891] x3 : ffffffc008ae2e28 x2 : 0000000000000000
> +<4>[ 22.690894] x1 : 0000000000000000 x0 : 0000000000000000
> +<4>[ 22.690896] Call trace:
> +<4>[ 22.690902] do_lttng_statedump+0xcc/0x8a8 [lttng_statedump]
> +<4>[ 22.690905] lttng_statedump_start+0x20/0x30 [lttng_statedump]
> +<4>[ 22.690981] lttng_session_enable+0xf0/0x120 [lttng_tracer]
> +<4>[ 22.691018] lttng_session_ioctl+0x22c/0x328 [lttng_tracer]
> +<4>[ 22.691026] compat_sys_ioctl+0x110/0x778
> +
> +Signed-off-by: Liguang Li <liguang.li at windriver.com>
> +
> +Upstream-Status: Pending
> +
> +Signed-off-by: Li Zhou <li.zhou at windriver.com>
> +---
> + lttng-statedump-impl.c | 2 +-
> + 1 file changed, 1 insertion(+), 1 deletion(-)
> +
> +diff --git a/lttng-statedump-impl.c b/lttng-statedump-impl.c
> +index 1c09e51..fb609e3 100644
> +--- a/lttng-statedump-impl.c
> ++++ b/lttng-statedump-impl.c
> +@@ -397,7 +397,7 @@ void lttng_statedump_process_ns(struct lttng_session *session,
> + do {
> + trace_lttng_statedump_process_state(session,
> + p, type, mode, submode, status, pid_ns);
> +- pid_ns = pid_ns->parent;
> ++ pid_ns = pid_ns ? pid_ns->parent : NULL;
> + } while (pid_ns);
> + }
> +
> +--
> +1.9.1
> +
> diff --git a/meta/recipes-kernel/lttng/lttng-modules_2.11.1.bb b/meta/recipes-kernel/lttng/lttng-modules_2.11.1.bb
> index c833ff7..cbd43e3 100644
> --- a/meta/recipes-kernel/lttng/lttng-modules_2.11.1.bb
> +++ b/meta/recipes-kernel/lttng/lttng-modules_2.11.1.bb
> @@ -11,6 +11,7 @@ COMPATIBLE_HOST = '(x86_64|i.86|powerpc|aarch64|mips|nios2|arm|riscv).*-linux'
> SRC_URI = "https://lttng.org/files/${BPN}/${BPN}-${PV}.tar.bz2 \
> file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
> file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
> + file://0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch \
> "
>
> SRC_URI[md5sum] = "0d964723c8765b39835e5e6efc60a604"
> @@ -36,6 +37,7 @@ DEFAULT_PREFERENCE_class-devupstream = "-1"
> SRC_URI_class-devupstream = "git://git.lttng.org/lttng-modules;branch=stable-2.11 \
> file://Makefile-Do-not-fail-if-CONFIG_TRACEPOINTS-is-not-en.patch \
> file://BUILD_RUNTIME_BUG_ON-vs-gcc7.patch \
> + file://0001-lttng-modules-Check-the-pid_ns-before-using-it-becau.patch \
> "
> SRCREV_class-devupstream = "6ad0e68b43c3e52fcb3d47c4d823a7b84aeb443a"
> PV_class-devupstream = "2.11.1+git${SRCPV}"
> --
> 1.9.1
>
> --
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