The kheaders archive consisting of the kernel headers used for compiling
bpf programs is in /proc. However there is concern that moving it here
will make it permanent. Let us move it to /sys/kernel as discussed [1].
[1] https://lore.kernel.org/patchwork/patch/1067310/#1265969
Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: Joel Fernandes (Google) <[email protected]>
---
This patch applies on top of the previous patch that was applied to the
driver tree:
https://lore.kernel.org/patchwork/patch/1067310/
v2->v3: Fixed sysfs file mode nit (Greg).
v1->v2: Fixed some kconfig nits.
init/Kconfig | 16 ++++-----
kernel/Makefile | 4 +--
kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +-
kernel/kheaders.c | 40 +++++++++------------
4 files changed, 26 insertions(+), 36 deletions(-)
rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%)
diff --git a/init/Kconfig b/init/Kconfig
index 26a364a95b57..c3661991b089 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -579,15 +579,13 @@ config IKCONFIG_PROC
This option enables access to the kernel configuration file
through /proc/config.gz.
-config IKHEADERS_PROC
- tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
- depends on PROC_FS
- help
- This option enables access to the kernel header and other artifacts that
- are generated during the build process. These can be used to build eBPF
- tracing programs, or similar programs. If you build the headers as a
- module, a module called kheaders.ko is built which can be loaded on-demand
- to get access to the headers.
+config IKHEADERS
+ tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
+ help
+ This option enables access to the in-kernel headers that are generated during
+ the build process. These can be used to build eBPF tracing programs,
+ or similar programs. If you build the headers as a module, a module called
+ kheaders.ko is built which can be loaded on-demand to get access to headers.
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
diff --git a/kernel/Makefile b/kernel/Makefile
index 12399614c350..b32a558fae2f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,7 +70,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
obj-$(CONFIG_IKCONFIG) += configs.o
-obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
+obj-$(CONFIG_IKHEADERS) += kheaders.o
obj-$(CONFIG_SMP) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -126,7 +126,7 @@ $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
$(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
quiet_cmd_genikh = CHK $(obj)/kheaders_data.tar.xz
-cmd_genikh = $(srctree)/kernel/gen_ikh_data.sh $@
+cmd_genikh = $(srctree)/kernel/gen_kheaders.sh $@
$(obj)/kheaders_data.tar.xz: FORCE
$(call cmd,genikh)
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_kheaders.sh
similarity index 98%
rename from kernel/gen_ikh_data.sh
rename to kernel/gen_kheaders.sh
index 591a94f7b387..581b83534587 100755
--- a/kernel/gen_ikh_data.sh
+++ b/kernel/gen_kheaders.sh
@@ -2,7 +2,7 @@
# SPDX-License-Identifier: GPL-2.0
# This script generates an archive consisting of kernel headers
-# for CONFIG_IKHEADERS_PROC.
+# for CONFIG_IKHEADERS.
set -e
spath="$(dirname "$(readlink -f "$0")")"
kroot="$spath/.."
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
index 70ae6052920d..8f69772af77b 100644
--- a/kernel/kheaders.c
+++ b/kernel/kheaders.c
@@ -8,9 +8,8 @@
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/proc_fs.h>
+#include <linux/kobject.h>
#include <linux/init.h>
-#include <linux/uaccess.h>
/*
* Define kernel_headers_data and kernel_headers_data_end, within which the
@@ -31,39 +30,32 @@ extern char kernel_headers_data;
extern char kernel_headers_data_end;
static ssize_t
-ikheaders_read_current(struct file *file, char __user *buf,
- size_t len, loff_t *offset)
+ikheaders_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t off, size_t len)
{
- return simple_read_from_buffer(buf, len, offset,
- &kernel_headers_data,
- &kernel_headers_data_end -
- &kernel_headers_data);
+ memcpy(buf, &kernel_headers_data + off, len);
+ return len;
}
-static const struct file_operations ikheaders_file_ops = {
- .read = ikheaders_read_current,
- .llseek = default_llseek,
+static struct bin_attribute kheaders_attr __ro_after_init = {
+ .attr = {
+ .name = "kheaders.tar.xz",
+ .mode = 0444,
+ },
+ .read = &ikheaders_read,
};
static int __init ikheaders_init(void)
{
- struct proc_dir_entry *entry;
-
- /* create the current headers file */
- entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
- &ikheaders_file_ops);
- if (!entry)
- return -ENOMEM;
-
- proc_set_size(entry,
- &kernel_headers_data_end -
- &kernel_headers_data);
- return 0;
+ kheaders_attr.size = (&kernel_headers_data_end -
+ &kernel_headers_data);
+ return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
}
static void __exit ikheaders_cleanup(void)
{
- remove_proc_entry("kheaders.tar.xz", NULL);
+ sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
}
module_init(ikheaders_init);
--
2.21.0.1020.gf2820cf01a-goog
On Mon, May 6, 2019 at 10:37 AM Joel Fernandes (Google)
<[email protected]> wrote:
>
> The kheaders archive consisting of the kernel headers used for compiling
> bpf programs is in /proc. However there is concern that moving it here
> will make it permanent. Let us move it to /sys/kernel as discussed [1].
>
> [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969
>
> Suggested-by: Steven Rostedt <[email protected]>
> Signed-off-by: Joel Fernandes (Google) <[email protected]>
> ---
> This patch applies on top of the previous patch that was applied to the
> driver tree:
> https://lore.kernel.org/patchwork/patch/1067310/
>
> v2->v3: Fixed sysfs file mode nit (Greg).
> v1->v2: Fixed some kconfig nits.
>
> init/Kconfig | 16 ++++-----
> kernel/Makefile | 4 +--
> kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +-
> kernel/kheaders.c | 40 +++++++++------------
> 4 files changed, 26 insertions(+), 36 deletions(-)
> rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%)
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 26a364a95b57..c3661991b089 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -579,15 +579,13 @@ config IKCONFIG_PROC
> This option enables access to the kernel configuration file
> through /proc/config.gz.
>
> -config IKHEADERS_PROC
> - tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
> - depends on PROC_FS
> - help
> - This option enables access to the kernel header and other artifacts that
> - are generated during the build process. These can be used to build eBPF
> - tracing programs, or similar programs. If you build the headers as a
> - module, a module called kheaders.ko is built which can be loaded on-demand
> - to get access to the headers.
> +config IKHEADERS
> + tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
I suggested "depends on SYSFS" twice, both in v1 and v2.
https://lore.kernel.org/patchwork/patch/1069806/#1266147
https://lore.kernel.org/patchwork/patch/1070005/#1266279
> + help
> + This option enables access to the in-kernel headers that are generated during
> + the build process. These can be used to build eBPF tracing programs,
> + or similar programs. If you build the headers as a module, a module called
> + kheaders.ko is built which can be loaded on-demand to get access to headers.
>
> config LOG_BUF_SHIFT
> int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
--
Best Regards
Masahiro Yamada
On Wed, May 08, 2019 at 12:43:34PM +0900, Masahiro Yamada wrote:
> On Mon, May 6, 2019 at 10:37 AM Joel Fernandes (Google)
> <[email protected]> wrote:
> >
> > The kheaders archive consisting of the kernel headers used for compiling
> > bpf programs is in /proc. However there is concern that moving it here
> > will make it permanent. Let us move it to /sys/kernel as discussed [1].
> >
> > [1] https://lore.kernel.org/patchwork/patch/1067310/#1265969
> >
> > Suggested-by: Steven Rostedt <[email protected]>
> > Signed-off-by: Joel Fernandes (Google) <[email protected]>
> > ---
> > This patch applies on top of the previous patch that was applied to the
> > driver tree:
> > https://lore.kernel.org/patchwork/patch/1067310/
> >
> > v2->v3: Fixed sysfs file mode nit (Greg).
> > v1->v2: Fixed some kconfig nits.
> >
> > init/Kconfig | 16 ++++-----
> > kernel/Makefile | 4 +--
> > kernel/{gen_ikh_data.sh => gen_kheaders.sh} | 2 +-
> > kernel/kheaders.c | 40 +++++++++------------
> > 4 files changed, 26 insertions(+), 36 deletions(-)
> > rename kernel/{gen_ikh_data.sh => gen_kheaders.sh} (98%)
> >
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 26a364a95b57..c3661991b089 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -579,15 +579,13 @@ config IKCONFIG_PROC
> > This option enables access to the kernel configuration file
> > through /proc/config.gz.
> >
> > -config IKHEADERS_PROC
> > - tristate "Enable kernel header artifacts through /proc/kheaders.tar.xz"
> > - depends on PROC_FS
> > - help
> > - This option enables access to the kernel header and other artifacts that
> > - are generated during the build process. These can be used to build eBPF
> > - tracing programs, or similar programs. If you build the headers as a
> > - module, a module called kheaders.ko is built which can be loaded on-demand
> > - to get access to the headers.
> > +config IKHEADERS
> > + tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
>
>
> I suggested "depends on SYSFS" twice, both in v1 and v2.
>
> https://lore.kernel.org/patchwork/patch/1069806/#1266147
> https://lore.kernel.org/patchwork/patch/1070005/#1266279
Sorry about missing that. I have made a note of this, and can address it in a
later patch. There is a more pressing issue with allmodconfig regression
times so I will look into that first. Also a vacation is taking up some of my
time.
Needless to say I will get to it soon and the point has been duly noted!
thanks,
- Joel