diff options
| -rw-r--r-- | fs/coredump.c | 4 | ||||
| -rw-r--r-- | fs/exec.c | 2 | ||||
| -rw-r--r-- | fs/pidfs.c | 7 | ||||
| -rw-r--r-- | fs/proc/base.c | 8 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 12 | ||||
| -rw-r--r-- | include/linux/sched/coredump.h | 18 |
6 files changed, 43 insertions, 8 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index 5dce257c67fc..f9d82ffc4b88 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -1103,8 +1103,10 @@ void vfs_coredump(const kernel_siginfo_t *siginfo) * We must use the same mm->flags while dumping core to avoid * inconsistency of bit flags, since this flag is not protected * by any locks. + * + * Note that we only care about MMF_DUMP* flags. */ - .mm_flags = mm->flags, + .mm_flags = __mm_flags_get_dumpable(mm), .vma_meta = NULL, .cpu = raw_smp_processor_id(), }; diff --git a/fs/exec.c b/fs/exec.c index 2a1e5e4042a1..dbac0e84cc3e 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1999,7 +1999,7 @@ void set_dumpable(struct mm_struct *mm, int value) if (WARN_ON((unsigned)value > SUID_DUMP_ROOT)) return; - set_mask_bits(&mm->flags, MMF_DUMPABLE_MASK, value); + __mm_flags_set_mask_dumpable(mm, value); } SYSCALL_DEFINE3(execve, diff --git a/fs/pidfs.c b/fs/pidfs.c index 108e7527f837..9913c5268fef 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -357,8 +357,11 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg) if ((kinfo.mask & PIDFD_INFO_COREDUMP) && !(kinfo.coredump_mask)) { task_lock(task); - if (task->mm) - kinfo.coredump_mask = pidfs_coredump_mask(task->mm->flags); + if (task->mm) { + unsigned long flags = __mm_flags_get_dumpable(task->mm); + + kinfo.coredump_mask = pidfs_coredump_mask(flags); + } task_unlock(task); } diff --git a/fs/proc/base.c b/fs/proc/base.c index 62d35631ba8c..f0c093c58aaf 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2962,8 +2962,10 @@ static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf, ret = 0; mm = get_task_mm(task); if (mm) { + unsigned long flags = __mm_flags_get_dumpable(mm); + len = snprintf(buffer, sizeof(buffer), "%08lx\n", - ((mm->flags & MMF_DUMP_FILTER_MASK) >> + ((flags & MMF_DUMP_FILTER_MASK) >> MMF_DUMP_FILTER_SHIFT)); mmput(mm); ret = simple_read_from_buffer(buf, count, ppos, buffer, len); @@ -3002,9 +3004,9 @@ static ssize_t proc_coredump_filter_write(struct file *file, for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) { if (val & mask) - set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); + mm_flags_set(i + MMF_DUMP_FILTER_SHIFT, mm); else - clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags); + mm_flags_clear(i + MMF_DUMP_FILTER_SHIFT, mm); } mmput(mm); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 0e001dbad455..9d224075d895 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1255,6 +1255,18 @@ static inline unsigned long __mm_flags_get_word(const struct mm_struct *mm) return bitmap_read(bitmap, 0, BITS_PER_LONG); } +/* + * Update the first system word of mm flags ONLY, applying the specified mask to + * it, then setting all flags specified by bits. + */ +static inline void __mm_flags_set_mask_bits_word(struct mm_struct *mm, + unsigned long mask, unsigned long bits) +{ + unsigned long *bitmap = ACCESS_PRIVATE(&mm->_flags, __mm_flags); + + set_mask_bits(bitmap, mask, bits); +} + #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ MT_FLAGS_USE_RCU) extern struct mm_struct init_mm; diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h index 6eb65ceed213..b7fafe999073 100644 --- a/include/linux/sched/coredump.h +++ b/include/linux/sched/coredump.h @@ -8,6 +8,20 @@ #define SUID_DUMP_USER 1 /* Dump as user of process */ #define SUID_DUMP_ROOT 2 /* Dump as root */ +static inline unsigned long __mm_flags_get_dumpable(struct mm_struct *mm) +{ + /* + * By convention, dumpable bits are contained in first 32 bits of the + * bitmap, so we can simply access this first unsigned long directly. + */ + return __mm_flags_get_word(mm); +} + +static inline void __mm_flags_set_mask_dumpable(struct mm_struct *mm, int value) +{ + __mm_flags_set_mask_bits_word(mm, MMF_DUMPABLE_MASK, value); +} + extern void set_dumpable(struct mm_struct *mm, int value); /* * This returns the actual value of the suid_dumpable flag. For things @@ -22,7 +36,9 @@ static inline int __get_dumpable(unsigned long mm_flags) static inline int get_dumpable(struct mm_struct *mm) { - return __get_dumpable(mm->flags); + unsigned long flags = __mm_flags_get_dumpable(mm); + + return __get_dumpable(flags); } #endif /* _LINUX_SCHED_COREDUMP_H */ |