Hello Will,
Looks good to me =)
On 15 September 2015 at 18:20, Will Deacon <will.deacon@xxxxxxx> wrote:
> Hi Dmitri,
>
> On Fri, Sep 11, 2015 at 03:40:00PM +0100, Dimitri John Ledkov wrote:
>> If one typically only boots full disk-images, one wouldn't necessaraly
>> want to statically link glibc, for the guest-init feature of the
>> kvmtool. As statically linked glibc triggers haevy security
>> maintainance.
>>
>> Signed-off-by: Dimitri John Ledkov <dimitri.j.ledkov@xxxxxxxxx>
>> ---
>> Changes since v1:
>> - rename CONFIG_HAS_LIBC to CONFIG_GUEST_INIT for clarity
>> - use more ifdefs, instead of runtime check of _binary_guest_init_size==0
>
> The idea looks good, but I think we can tidy some of this up at the same
> time by moving all the guest_init code in builtin_setup.c.
>
> How about the patch below?
>
> Will
>
> --->8
>
> From cdce942c1a3a04635065a7972ca4e21386664756 Mon Sep 17 00:00:00 2001
> From: Dimitri John Ledkov <dimitri.j.ledkov@xxxxxxxxx>
> Date: Fri, 11 Sep 2015 15:40:00 +0100
> Subject: [PATCH] Make static libc and guest-init functionality optional.
>
> If one typically only boots full disk-images, one wouldn't necessaraly
> want to statically link glibc, for the guest-init feature of the
> kvmtool. As statically linked glibc triggers haevy security
> maintainance.
>
> Signed-off-by: Dimitri John Ledkov <dimitri.j.ledkov@xxxxxxxxx>
> [will: moved all the guest_init handling into builtin_setup.c]
> Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
> ---
> Makefile | 12 +++++++-----
> builtin-run.c | 29 +----------------------------
> builtin-setup.c | 19 ++++++++++++++-----
> include/kvm/builtin-setup.h | 1 +
> 4 files changed, 23 insertions(+), 38 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 7b17d529d13b..f1701aa7b8ec 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -34,8 +34,6 @@ bindir_SQ = $(subst ','\'',$(bindir))
> PROGRAM := lkvm
> PROGRAM_ALIAS := vm
>
> -GUEST_INIT := guest/init
> -
> OBJS += builtin-balloon.o
> OBJS += builtin-debug.o
> OBJS += builtin-help.o
> @@ -279,8 +277,13 @@ ifeq ($(LTO),1)
> endif
> endif
>
> -ifneq ($(call try-build,$(SOURCE_STATIC),,-static),y)
> - $(error No static libc found. Please install glibc-static package.)
> +ifeq ($(call try-build,$(SOURCE_STATIC),,-static),y)
> + CFLAGS += -DCONFIG_GUEST_INIT
> + GUEST_INIT := guest/init
> + GUEST_OBJS = guest/guest_init.o
> +else
> + $(warning No static libc found. Skipping guest init)
> + NOTFOUND += static-libc
> endif
>
> ifeq (y,$(ARCH_WANT_LIBFDT))
> @@ -356,7 +359,6 @@ c_flags = -Wp,-MD,$(depfile) $(CFLAGS)
> # $(OTHEROBJS) are things that do not get substituted like this.
> #
> STATIC_OBJS = $(patsubst %.o,%.static.o,$(OBJS) $(OBJS_STATOPT))
> -GUEST_OBJS = guest/guest_init.o
>
> $(PROGRAM)-static: $(STATIC_OBJS) $(OTHEROBJS) $(GUEST_INIT)
> $(E) " LINK " $@
> diff --git a/builtin-run.c b/builtin-run.c
> index 1ee75ad3f010..e0c87329e52b 100644
> --- a/builtin-run.c
> +++ b/builtin-run.c
> @@ -59,9 +59,6 @@ static int kvm_run_wrapper;
>
> bool do_debug_print = false;
>
> -extern char _binary_guest_init_start;
> -extern char _binary_guest_init_size;
> -
> static const char * const run_usage[] = {
> "lkvm run [<options>] [<kernel image>]",
> NULL
> @@ -345,30 +342,6 @@ void kvm_run_help(void)
> usage_with_options(run_usage, options);
> }
>
> -static int kvm_setup_guest_init(struct kvm *kvm)
> -{
> - const char *rootfs = kvm->cfg.custom_rootfs_name;
> - char tmp[PATH_MAX];
> - size_t size;
> - int fd, ret;
> - char *data;
> -
> - /* Setup /virt/init */
> - size = (size_t)&_binary_guest_init_size;
> - data = (char *)&_binary_guest_init_start;
> - snprintf(tmp, PATH_MAX, "%s%s/virt/init", kvm__get_dir(), rootfs);
> - remove(tmp);
> - fd = open(tmp, O_CREAT | O_WRONLY, 0755);
> - if (fd < 0)
> - die("Fail to setup %s", tmp);
> - ret = xwrite(fd, data, size);
> - if (ret < 0)
> - die("Fail to setup %s", tmp);
> - close(fd);
> -
> - return 0;
> -}
> -
> static int kvm_run_set_sandbox(struct kvm *kvm)
> {
> const char *guestfs_name = kvm->cfg.custom_rootfs_name;
> @@ -631,7 +604,7 @@ static struct kvm *kvm_cmd_run_init(int argc, const char **argv)
>
> if (!kvm->cfg.no_dhcp)
> strcat(real_cmdline, " ip=dhcp");
> - if (kvm_setup_guest_init(kvm))
> + if (kvm_setup_guest_init(kvm->cfg.custom_rootfs_name))
> die("Failed to setup init for guest.");
> }
> } else if (!strstr(real_cmdline, "root=")) {
> diff --git a/builtin-setup.c b/builtin-setup.c
> index 8b45c5645ad4..40fef15dbbe4 100644
> --- a/builtin-setup.c
> +++ b/builtin-setup.c
> @@ -16,9 +16,6 @@
> #include <sys/mman.h>
> #include <fcntl.h>
>
> -extern char _binary_guest_init_start;
> -extern char _binary_guest_init_size;
> -
> static const char *instance_name;
>
> static const char * const setup_usage[] = {
> @@ -124,7 +121,11 @@ static const char *guestfs_symlinks[] = {
> "/etc/ld.so.conf",
> };
>
> -static int copy_init(const char *guestfs_name)
> +#ifdef CONFIG_GUEST_INIT
> +extern char _binary_guest_init_start;
> +extern char _binary_guest_init_size;
> +
> +int kvm_setup_guest_init(const char *guestfs_name)
> {
> char path[PATH_MAX];
> size_t size;
> @@ -144,7 +145,15 @@ static int copy_init(const char *guestfs_name)
> close(fd);
>
> return 0;
> +
> +}
> +#else
> +int kvm_setup_guest_init(const char *guestfs_name)
> +{
> + die("Guest init image not compiled in");
> + return 0;
> }
> +#endif
>
> static int copy_passwd(const char *guestfs_name)
> {
> @@ -222,7 +231,7 @@ static int do_setup(const char *guestfs_name)
> make_guestfs_symlink(guestfs_name, guestfs_symlinks[i]);
> }
>
> - ret = copy_init(guestfs_name);
> + ret = kvm_setup_guest_init(guestfs_name);
> if (ret < 0)
> return ret;
>
> diff --git a/include/kvm/builtin-setup.h b/include/kvm/builtin-setup.h
> index 4a8d7ee39425..239bbbdce09e 100644
> --- a/include/kvm/builtin-setup.h
> +++ b/include/kvm/builtin-setup.h
> @@ -7,5 +7,6 @@ int kvm_cmd_setup(int argc, const char **argv, const char *prefix);
> void kvm_setup_help(void) NORETURN;
> int kvm_setup_create_new(const char *guestfs_name);
> void kvm_setup_resolv(const char *guestfs_name);
> +int kvm_setup_guest_init(const char *guestfs_name);
>
> #endif
> --
> 2.1.4
>
>
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--
Regards,
Dimitri.
101 sleeps till Christmas
https://clearlinux.org
Open Source Technology Center
Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ.
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