On Sat, May 4, 2019 at 9:26 PM Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> 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 <rostedt@xxxxxxxxxxx> > Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> > --- > This patch applies on top of the previous patch that was applied to the > driver tree: > https://lore.kernel.org/patchwork/patch/1067310/ > > v1->v2: Fixed some kconfig nits (Masami). My name is Masahiro, just in case. > > 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" In v1, I suggested to change "depends on PROC_FS" to "depends on SYSFS". fs/sysfs/ must be compiled to make this feature work. > + 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 While you are touching the help, could you make the number of spaces between sentences consistent? Thanks. > + 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..6a16f8f6898d 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 = S_IRUGO, > + }, > + .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 -- Best Regards Masahiro Yamada
