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    Subject[PATCH v3 07/10] mm: use mm->exe_file instead of first VM_EXECUTABLE vma->vm_file
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    Date
    Some security modules and oprofile still uses VM_EXECUTABLE for retrieving
    task's executable file, after this patch they will use mm->exe_file directly.
    mm->exe_file protected with mm->mmap_sem, so locking stays the same.

    Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
    Acked-by: Chris Metcalf <cmetcalf@tilera.com> #arch/tile
    Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> #security/tomoyo
    Cc: Robert Richter <robert.richter@amd.com>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Eric Paris <eparis@redhat.com>
    Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
    Cc: James Morris <james.l.morris@oracle.com>
    Cc: linux-security-module@vger.kernel.org
    Cc: oprofile-list@lists.sf.net
    ---
    arch/powerpc/oprofile/cell/spu_task_sync.c | 15 ++++-----------
    arch/tile/mm/elf.c | 19 +++++++------------
    drivers/oprofile/buffer_sync.c | 17 +++--------------
    kernel/auditsc.c | 13 ++-----------
    kernel/fork.c | 3 +--
    security/tomoyo/util.c | 9 ++-------
    6 files changed, 19 insertions(+), 57 deletions(-)

    diff --git a/arch/powerpc/oprofile/cell/spu_task_sync.c b/arch/powerpc/oprofile/cell/spu_task_sync.c
    index 642fca1..28f1af2 100644
    --- a/arch/powerpc/oprofile/cell/spu_task_sync.c
    +++ b/arch/powerpc/oprofile/cell/spu_task_sync.c
    @@ -304,7 +304,7 @@ static inline unsigned long fast_get_dcookie(struct path *path)
    return cookie;
    }

    -/* Look up the dcookie for the task's first VM_EXECUTABLE mapping,
    +/* Look up the dcookie for the task's mm->exe_file,
    * which corresponds loosely to "application name". Also, determine
    * the offset for the SPU ELF object. If computed offset is
    * non-zero, it implies an embedded SPU object; otherwise, it's a
    @@ -321,7 +321,6 @@ get_exec_dcookie_and_offset(struct spu *spu, unsigned int *offsetp,
    {
    unsigned long app_cookie = 0;
    unsigned int my_offset = 0;
    - struct file *app = NULL;
    struct vm_area_struct *vma;
    struct mm_struct *mm = spu->mm;

    @@ -330,16 +329,10 @@ get_exec_dcookie_and_offset(struct spu *spu, unsigned int *offsetp,

    down_read(&mm->mmap_sem);

    - for (vma = mm->mmap; vma; vma = vma->vm_next) {
    - if (!vma->vm_file)
    - continue;
    - if (!(vma->vm_flags & VM_EXECUTABLE))
    - continue;
    - app_cookie = fast_get_dcookie(&vma->vm_file->f_path);
    + if (mm->exe_file) {
    + app_cookie = fast_get_dcookie(&mm->exe_file->f_path);
    pr_debug("got dcookie for %s\n",
    - vma->vm_file->f_dentry->d_name.name);
    - app = vma->vm_file;
    - break;
    + mm->exe_file->f_dentry->d_name.name);
    }

    for (vma = mm->mmap; vma; vma = vma->vm_next) {
    diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
    index 758b603..3cfa98b 100644
    --- a/arch/tile/mm/elf.c
    +++ b/arch/tile/mm/elf.c
    @@ -36,19 +36,14 @@ static void sim_notify_exec(const char *binary_name)
    } while (c);
    }

    -static int notify_exec(void)
    +static int notify_exec(struct mm_struct *mm)
    {
    int retval = 0; /* failure */
    - struct vm_area_struct *vma = current->mm->mmap;
    - while (vma) {
    - if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
    - break;
    - vma = vma->vm_next;
    - }
    - if (vma) {
    +
    + if (mm->exe_file) {
    char *buf = (char *) __get_free_page(GFP_KERNEL);
    if (buf) {
    - char *path = d_path(&vma->vm_file->f_path,
    + char *path = d_path(&mm->exe_file->f_path,
    buf, PAGE_SIZE);
    if (!IS_ERR(path)) {
    sim_notify_exec(path);
    @@ -106,16 +101,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
    unsigned long vdso_base;
    int retval = 0;

    + down_write(&mm->mmap_sem);
    +
    /*
    * Notify the simulator that an exec just occurred.
    * If we can't find the filename of the mapping, just use
    * whatever was passed as the linux_binprm filename.
    */
    - if (!notify_exec())
    + if (!notify_exec(mm))
    sim_notify_exec(bprm->filename);

    - down_write(&mm->mmap_sem);
    -
    /*
    * MAYWRITE to allow gdb to COW and set breakpoints
    */
    diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
    index f34b5b2..d93b2b6 100644
    --- a/drivers/oprofile/buffer_sync.c
    +++ b/drivers/oprofile/buffer_sync.c
    @@ -216,7 +216,7 @@ static inline unsigned long fast_get_dcookie(struct path *path)
    }


    -/* Look up the dcookie for the task's first VM_EXECUTABLE mapping,
    +/* Look up the dcookie for the task's mm->exe_file,
    * which corresponds loosely to "application name". This is
    * not strictly necessary but allows oprofile to associate
    * shared-library samples with particular applications
    @@ -224,21 +224,10 @@ static inline unsigned long fast_get_dcookie(struct path *path)
    static unsigned long get_exec_dcookie(struct mm_struct *mm)
    {
    unsigned long cookie = NO_COOKIE;
    - struct vm_area_struct *vma;
    -
    - if (!mm)
    - goto out;

    - for (vma = mm->mmap; vma; vma = vma->vm_next) {
    - if (!vma->vm_file)
    - continue;
    - if (!(vma->vm_flags & VM_EXECUTABLE))
    - continue;
    - cookie = fast_get_dcookie(&vma->vm_file->f_path);
    - break;
    - }
    + if (mm && mm->exe_file)
    + cookie = fast_get_dcookie(&mm->exe_file->f_path);

    -out:
    return cookie;
    }

    diff --git a/kernel/auditsc.c b/kernel/auditsc.c
    index 4b96415..31cf885 100644
    --- a/kernel/auditsc.c
    +++ b/kernel/auditsc.c
    @@ -1158,7 +1158,6 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk
    {
    char name[sizeof(tsk->comm)];
    struct mm_struct *mm = tsk->mm;
    - struct vm_area_struct *vma;

    /* tsk == current */

    @@ -1168,16 +1167,8 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk

    if (mm) {
    down_read(&mm->mmap_sem);
    - vma = mm->mmap;
    - while (vma) {
    - if ((vma->vm_flags & VM_EXECUTABLE) &&
    - vma->vm_file) {
    - audit_log_d_path(ab, " exe=",
    - &vma->vm_file->f_path);
    - break;
    - }
    - vma = vma->vm_next;
    - }
    + if (mm->exe_file)
    + audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
    up_read(&mm->mmap_sem);
    }
    audit_log_task_context(ab);
    diff --git a/kernel/fork.c b/kernel/fork.c
    index 8efac1f..bd5c4c5 100644
    --- a/kernel/fork.c
    +++ b/kernel/fork.c
    @@ -659,8 +659,7 @@ struct file *get_mm_exe_file(struct mm_struct *mm)
    {
    struct file *exe_file;

    - /* We need mmap_sem to protect against races with removal of
    - * VM_EXECUTABLE vmas */
    + /* We need mmap_sem to protect against races with removal of exe_file */
    down_read(&mm->mmap_sem);
    exe_file = mm->exe_file;
    if (exe_file)
    diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
    index 867558c..2952ba5 100644
    --- a/security/tomoyo/util.c
    +++ b/security/tomoyo/util.c
    @@ -949,18 +949,13 @@ bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
    const char *tomoyo_get_exe(void)
    {
    struct mm_struct *mm = current->mm;
    - struct vm_area_struct *vma;
    const char *cp = NULL;

    if (!mm)
    return NULL;
    down_read(&mm->mmap_sem);
    - for (vma = mm->mmap; vma; vma = vma->vm_next) {
    - if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
    - cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
    - break;
    - }
    - }
    + if (mm->exe_file)
    + cp = tomoyo_realpath_from_path(&mm->exe_file->f_path);
    up_read(&mm->mmap_sem);
    return cp;
    }


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