From f7b101d33046a837c2aa4526cef28a3c785d7af2 Mon Sep 17 00:00:00 2001 From: "Joel Fernandes (Google)" Date: Wed, 15 May 2019 17:35:51 -0400 Subject: kheaders: Move from proc to sysfs 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 Signed-off-by: Joel Fernandes (Google) Signed-off-by: Greg Kroah-Hartman --- init/Kconfig | 17 +++++----- kernel/Makefile | 4 +-- kernel/gen_ikh_data.sh | 89 -------------------------------------------------- kernel/gen_kheaders.sh | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/kheaders.c | 40 +++++++++-------------- 5 files changed, 115 insertions(+), 124 deletions(-) delete mode 100755 kernel/gen_ikh_data.sh create mode 100755 kernel/gen_kheaders.sh diff --git a/init/Kconfig b/init/Kconfig index 8b9ffe236e4f..16a7540d60c8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -579,15 +579,14 @@ 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" + depends on SYSFS + 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 33824f0385b3..a8d923b5481b 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -71,7 +71,7 @@ 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 @@ -127,7 +127,7 @@ $(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 = $(CONFIG_SHELL) $(srctree)/kernel/gen_ikh_data.sh $@ +cmd_genikh = $(CONFIG_SHELL) $(srctree)/kernel/gen_kheaders.sh $@ $(obj)/kheaders_data.tar.xz: FORCE $(call cmd,genikh) diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_ikh_data.sh deleted file mode 100755 index 591a94f7b387..000000000000 --- a/kernel/gen_ikh_data.sh +++ /dev/null @@ -1,89 +0,0 @@ -#!/bin/bash -# SPDX-License-Identifier: GPL-2.0 - -# This script generates an archive consisting of kernel headers -# for CONFIG_IKHEADERS_PROC. -set -e -spath="$(dirname "$(readlink -f "$0")")" -kroot="$spath/.." -outdir="$(pwd)" -tarfile=$1 -cpio_dir=$outdir/$tarfile.tmp - -# Script filename relative to the kernel source root -# We add it to the archive because it is small and any changes -# to this script will also cause a rebuild of the archive. -sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")" - -src_file_list=" -include/ -arch/$SRCARCH/include/ -$sfile -" - -obj_file_list=" -include/ -arch/$SRCARCH/include/ -" - -# Support incremental builds by skipping archive generation -# if timestamps of files being archived are not changed. - -# This block is useful for debugging the incremental builds. -# Uncomment it for debugging. -# iter=1 -# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter; -# else; iter=$(($(cat /tmp/iter) + 1)); fi -# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter -# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter - -# include/generated/compile.h is ignored because it is touched even when none -# of the source files changed. This causes pointless regeneration, so let us -# ignore them for md5 calculation. -pushd $kroot > /dev/null -src_files_md5="$(find $src_file_list -type f | - grep -v "include/generated/compile.h" | - xargs ls -lR | md5sum | cut -d ' ' -f1)" -popd > /dev/null -obj_files_md5="$(find $obj_file_list -type f | - grep -v "include/generated/compile.h" | - xargs ls -lR | md5sum | cut -d ' ' -f1)" - -if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi -if [ -f kernel/kheaders.md5 ] && - [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] && - [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] && - [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then - exit -fi - -if [ "${quiet}" != "silent_" ]; then - echo " GEN $tarfile" -fi - -rm -rf $cpio_dir -mkdir $cpio_dir - -pushd $kroot > /dev/null -for f in $src_file_list; - do find "$f" ! -name "*.cmd" ! -name ".*"; -done | cpio --quiet -pd $cpio_dir -popd > /dev/null - -# The second CPIO can complain if files already exist which can -# happen with out of tree builds. Just silence CPIO for now. -for f in $obj_file_list; - do find "$f" ! -name "*.cmd" ! -name ".*"; -done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1 - -# Remove comments except SDPX lines -find $cpio_dir -type f -print0 | - xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;' - -tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null - -echo "$src_files_md5" > kernel/kheaders.md5 -echo "$obj_files_md5" >> kernel/kheaders.md5 -echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5 - -rm -rf $cpio_dir diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh new file mode 100755 index 000000000000..581b83534587 --- /dev/null +++ b/kernel/gen_kheaders.sh @@ -0,0 +1,89 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +# This script generates an archive consisting of kernel headers +# for CONFIG_IKHEADERS. +set -e +spath="$(dirname "$(readlink -f "$0")")" +kroot="$spath/.." +outdir="$(pwd)" +tarfile=$1 +cpio_dir=$outdir/$tarfile.tmp + +# Script filename relative to the kernel source root +# We add it to the archive because it is small and any changes +# to this script will also cause a rebuild of the archive. +sfile="$(realpath --relative-to $kroot "$(readlink -f "$0")")" + +src_file_list=" +include/ +arch/$SRCARCH/include/ +$sfile +" + +obj_file_list=" +include/ +arch/$SRCARCH/include/ +" + +# Support incremental builds by skipping archive generation +# if timestamps of files being archived are not changed. + +# This block is useful for debugging the incremental builds. +# Uncomment it for debugging. +# iter=1 +# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter; +# else; iter=$(($(cat /tmp/iter) + 1)); fi +# find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter +# find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter + +# include/generated/compile.h is ignored because it is touched even when none +# of the source files changed. This causes pointless regeneration, so let us +# ignore them for md5 calculation. +pushd $kroot > /dev/null +src_files_md5="$(find $src_file_list -type f | + grep -v "include/generated/compile.h" | + xargs ls -lR | md5sum | cut -d ' ' -f1)" +popd > /dev/null +obj_files_md5="$(find $obj_file_list -type f | + grep -v "include/generated/compile.h" | + xargs ls -lR | md5sum | cut -d ' ' -f1)" + +if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi +if [ -f kernel/kheaders.md5 ] && + [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] && + [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] && + [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then + exit +fi + +if [ "${quiet}" != "silent_" ]; then + echo " GEN $tarfile" +fi + +rm -rf $cpio_dir +mkdir $cpio_dir + +pushd $kroot > /dev/null +for f in $src_file_list; + do find "$f" ! -name "*.cmd" ! -name ".*"; +done | cpio --quiet -pd $cpio_dir +popd > /dev/null + +# The second CPIO can complain if files already exist which can +# happen with out of tree builds. Just silence CPIO for now. +for f in $obj_file_list; + do find "$f" ! -name "*.cmd" ! -name ".*"; +done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1 + +# Remove comments except SDPX lines +find $cpio_dir -type f -print0 | + xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;' + +tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null + +echo "$src_files_md5" > kernel/kheaders.md5 +echo "$obj_files_md5" >> kernel/kheaders.md5 +echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5 + +rm -rf $cpio_dir 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 #include -#include +#include #include -#include /* * 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); -- cgit