From: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
To: dev@dpdk.org
Cc: Anatoly Burakov <anatoly.burakov@intel.com>,
Lewis Donzis <lew@perftech.com>,
Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Subject: [PATCH v2 1/2] contigmem: support including mapped buffers in core dump
Date: Fri, 25 Oct 2024 23:26:14 +0300 [thread overview]
Message-ID: <20241025202615.2581513-2-dmitry.kozliuk@gmail.com> (raw)
In-Reply-To: <20241025202615.2581513-1-dmitry.kozliuk@gmail.com>
It was impossible to include mapped contigmem buffers in core dump.
Add hw.contigmem.coredump_enable tunable to control the inclusion.
Mappings backed by OBJ_FICTITIOUS are excluded from core dump.
While contigmem is a device and its OBJT_DEVICE mappings get this flag,
they are actually backed by memory.
Clear OBJ_FICTITIOUS mapping bit to include them in core dump.
Do this only if hw.contigmem.coredump_enable=1.
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---
doc/guides/freebsd_gsg/build_dpdk.rst | 27 ++++++++++++++++++++-------
kernel/freebsd/contigmem/contigmem.c | 8 ++++++++
2 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/doc/guides/freebsd_gsg/build_dpdk.rst b/doc/guides/freebsd_gsg/build_dpdk.rst
index 86e8e5a805..387ec52820 100644
--- a/doc/guides/freebsd_gsg/build_dpdk.rst
+++ b/doc/guides/freebsd_gsg/build_dpdk.rst
@@ -86,6 +86,22 @@ module loading using::
kenv hw.contigmem.num_buffers=n
kenv hw.contigmem.buffer_size=m
+Where n is the number of blocks and m is the size in bytes of each area of
+contiguous memory. A default of two buffers of size 1073741824 bytes (1 Gigabyte)
+each is set during module load if they are not specified in the environment.
+
+Buffers are excluded from core dump by default.
+Mapped buffers can be included in core dump using the following tunable:
+
+ hw.contigmem.coredump_enable=1
+
+.. note::
+
+ Including contigmem buffers in core dump file increases its size,
+ which may fill the storage or overload the transport.
+ Buffers typically hold data processed by the application,
+ like network packets, which may contain sensitive information.
+
The kernel environment variables can also be specified during boot by placing the
following in ``/boot/loader.conf``:
@@ -93,15 +109,12 @@ following in ``/boot/loader.conf``:
hw.contigmem.num_buffers=n
hw.contigmem.buffer_size=m
+ hw.contigmem.coredump_enable=1
The variables can be inspected using the following command::
sysctl -a hw.contigmem
-Where n is the number of blocks and m is the size in bytes of each area of
-contiguous memory. A default of two buffers of size 1073741824 bytes (1 Gigabyte)
-each is set during module load if they are not specified in the environment.
-
The module can then be loaded using kldload::
kldload contigmem
@@ -115,13 +128,13 @@ up time. This can be achieved by placing lines similar to the following into
hw.contigmem.num_buffers=1
hw.contigmem.buffer_size=1073741824
+ hw.contigmem.coredump_enable=1
contigmem_load="YES"
.. note::
- The contigmem_load directive should be placed after any definitions of
- ``hw.contigmem.num_buffers`` and ``hw.contigmem.buffer_size`` if the default values
- are not to be used.
+ The ``contigmem_load`` directive should be placed after any definitions
+ of ``hw.contigmem.*`` if the default values are not to be used.
An error such as::
diff --git a/kernel/freebsd/contigmem/contigmem.c b/kernel/freebsd/contigmem/contigmem.c
index 7dd87599d9..591e46dded 100644
--- a/kernel/freebsd/contigmem/contigmem.c
+++ b/kernel/freebsd/contigmem/contigmem.c
@@ -51,6 +51,7 @@ static d_close_t contigmem_close;
static int contigmem_num_buffers = RTE_CONTIGMEM_DEFAULT_NUM_BUFS;
static int64_t contigmem_buffer_size = RTE_CONTIGMEM_DEFAULT_BUF_SIZE;
+static bool contigmem_coredump_enable;
static eventhandler_tag contigmem_eh_tag;
static struct contigmem_buffer contigmem_buffers[RTE_CONTIGMEM_MAX_NUM_BUFS];
@@ -59,6 +60,7 @@ static int contigmem_refcnt;
TUNABLE_INT("hw.contigmem.num_buffers", &contigmem_num_buffers);
TUNABLE_QUAD("hw.contigmem.buffer_size", &contigmem_buffer_size);
+TUNABLE_BOOL("hw.contigmem.coredump_enable", &contigmem_coredump_enable);
static SYSCTL_NODE(_hw, OID_AUTO, contigmem, CTLFLAG_RD, 0, "contigmem");
@@ -68,6 +70,8 @@ SYSCTL_QUAD(_hw_contigmem, OID_AUTO, buffer_size, CTLFLAG_RD,
&contigmem_buffer_size, 0, "Size of each contiguous buffer");
SYSCTL_INT(_hw_contigmem, OID_AUTO, num_references, CTLFLAG_RD,
&contigmem_refcnt, 0, "Number of references to contigmem");
+SYSCTL_BOOL(_hw_contigmem, OID_AUTO, coredump_enable, CTLFLAG_RD,
+ &contigmem_coredump_enable, 0, "Include mapped buffers in core dump");
static SYSCTL_NODE(_hw_contigmem, OID_AUTO, physaddr, CTLFLAG_RD, 0,
"physaddr");
@@ -357,5 +361,9 @@ contigmem_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size,
*obj = cdev_pager_allocate(vmh, OBJT_DEVICE, &contigmem_cdev_pager_ops,
size, nprot, *offset, curthread->td_ucred);
+ /* Mappings backed by OBJ_FICTITIOUS are excluded from core dump. */
+ if (contigmem_coredump_enable)
+ (*obj)->flags &= ~OBJ_FICTITIOUS;
+
return 0;
}
--
2.38.4
next prev parent reply other threads:[~2024-10-25 20:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-23 23:18 [PATCH] eal: support including mapped memory " Dmitry Kozlyuk
2024-10-24 2:19 ` Stephen Hemminger
2024-10-24 2:31 ` Stephen Hemminger
2024-10-24 7:07 ` Morten Brørup
2024-10-24 7:22 ` Morten Brørup
2024-10-24 8:25 ` Dmitry Kozlyuk
2024-10-24 12:55 ` Lewis Donzis
2024-10-24 16:38 ` Stephen Hemminger
2024-10-24 20:54 ` Dmitry Kozlyuk
2024-10-25 0:22 ` Dmitry Kozlyuk
2024-10-25 20:26 ` [PATCH v2 0/2] Hugepage inclusion " Dmitry Kozlyuk
2024-10-25 20:26 ` Dmitry Kozlyuk [this message]
2024-10-25 20:26 ` [PATCH v2 2/2] doc: add instruction for including hugepages " Dmitry Kozlyuk
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