lkml.org 
[lkml]   [2012]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCHv4 2/3] fs: Make core dump functionality optional
    Quoting Alex Kelly (alex.page.kelly@gmail.com):
    > Adds an expert Kconfig option, CONFIG_COREDUMP, which allows disabling of core dump.
    > This saves approximately 2.6k in the compiled kernel, and complements CONFIG_ELF_CORE,
    > which now depends on it.

    Is there another reason than the 2.6k to do this? My kernels range
    between 4.8 and 5M, so that's .05% size savings?

    I'm not saying nack (it's not my area anyway), just seem to be missing
    the point.

    > CONFIG_COREDUMP also disables coredump-related sysctls, except for suid_dumpable and
    > related functions, which are necessary for ptrace.
    >
    > Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com>
    > Reviewed-by: Josh Triplett <josh@joshtriplett.org>
    > ---
    > fs/Kconfig.binfmt | 8 ++++++++
    > fs/Makefile | 3 ++-
    > include/linux/binfmts.h | 4 ++++
    > init/Kconfig | 1 +
    > kernel/sysctl.c | 6 +++++-
    > 5 files changed, 20 insertions(+), 2 deletions(-)
    >
    > diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
    > index 0225742..0efd152 100644
    > --- a/fs/Kconfig.binfmt
    > +++ b/fs/Kconfig.binfmt
    > @@ -164,3 +164,11 @@ config BINFMT_MISC
    > You may say M here for module support and later load the module when
    > you have use for it; the module is called binfmt_misc. If you
    > don't know what to answer at this point, say Y.
    > +
    > +config COREDUMP
    > + bool "Enable core dump support" if EXPERT
    > + default y
    > + help
    > + This option enables support for performing core dumps. You almost
    > + certainly want to say Y here. Not necessary on systems that never
    > + need debugging or only ever run flawless code.
    > diff --git a/fs/Makefile b/fs/Makefile
    > index 8938f82..1d7af79 100644
    > --- a/fs/Makefile
    > +++ b/fs/Makefile
    > @@ -11,7 +11,7 @@ obj-y := open.o read_write.o file_table.o super.o \
    > attr.o bad_inode.o file.o filesystems.o namespace.o \
    > seq_file.o xattr.o libfs.o fs-writeback.o \
    > pnode.o drop_caches.o splice.o sync.o utimes.o \
    > - stack.o fs_struct.o statfs.o coredump.o
    > + stack.o fs_struct.o statfs.o
    >
    > ifeq ($(CONFIG_BLOCK),y)
    > obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
    > @@ -48,6 +48,7 @@ obj-$(CONFIG_FS_MBCACHE) += mbcache.o
    > obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o xattr_acl.o
    > obj-$(CONFIG_NFS_COMMON) += nfs_common/
    > obj-$(CONFIG_GENERIC_ACL) += generic_acl.o
    > +obj-$(CONFIG_COREDUMP) += coredump.o
    >
    > obj-$(CONFIG_FHANDLE) += fhandle.o
    >
    > diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
    > index 366422b..00e2e89 100644
    > --- a/include/linux/binfmts.h
    > +++ b/include/linux/binfmts.h
    > @@ -132,7 +132,11 @@ extern int copy_strings_kernel(int argc, const char *const *argv,
    > struct linux_binprm *bprm);
    > extern int prepare_bprm_creds(struct linux_binprm *bprm);
    > extern void install_exec_creds(struct linux_binprm *bprm);
    > +#ifdef CONFIG_COREDUMP
    > extern void do_coredump(long signr, int exit_code, struct pt_regs *regs);
    > +#else
    > +static inline void do_coredump(long signr, int exit_code, struct pt_regs *regs) {}
    > +#endif
    > extern void set_binfmt(struct linux_binfmt *new);
    > extern void free_bprm(struct linux_binprm *);
    >
    > diff --git a/init/Kconfig b/init/Kconfig
    > index af6c7f8..0e75056 100644
    > --- a/init/Kconfig
    > +++ b/init/Kconfig
    > @@ -1230,6 +1230,7 @@ config BUG
    > Just say Y.
    >
    > config ELF_CORE
    > + depends on COREDUMP
    > default y
    > bool "Enable ELF core dumps" if EXPERT
    > help
    > diff --git a/kernel/sysctl.c b/kernel/sysctl.c
    > index 87174ef..af57e84 100644
    > --- a/kernel/sysctl.c
    > +++ b/kernel/sysctl.c
    > @@ -97,10 +97,12 @@
    > extern int sysctl_overcommit_memory;
    > extern int sysctl_overcommit_ratio;
    > extern int max_threads;
    > -extern int core_uses_pid;
    > extern int suid_dumpable;
    > +#ifdef CONFIG_COREDUMP
    > +extern int core_uses_pid;
    > extern char core_pattern[];
    > extern unsigned int core_pipe_limit;
    > +#endif
    > extern int pid_max;
    > extern int min_free_kbytes;
    > extern int pid_max_min, pid_max_max;
    > @@ -404,6 +406,7 @@ static struct ctl_table kern_table[] = {
    > .mode = 0644,
    > .proc_handler = proc_dointvec,
    > },
    > +#ifdef CONFIG_COREDUMP
    > {
    > .procname = "core_uses_pid",
    > .data = &core_uses_pid,
    > @@ -425,6 +428,7 @@ static struct ctl_table kern_table[] = {
    > .mode = 0644,
    > .proc_handler = proc_dointvec,
    > },
    > +#endif
    > #ifdef CONFIG_PROC_SYSCTL
    > {
    > .procname = "tainted",
    > --
    > 1.7.11.2
    >


    \
     
     \ /
      Last update: 2012-08-10 16:02    [W:0.030 / U:0.048 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site