linux-imx/include/linux/sched/coredump.h
Florent Revest 2b00d1fd9a mm: add a NO_INHERIT flag to the PR_SET_MDWE prctl
[ Upstream commit 24e41bf8a6 ]

This extends the current PR_SET_MDWE prctl arg with a bit to indicate that
the process doesn't want MDWE protection to propagate to children.

To implement this no-inherit mode, the tag in current->mm->flags must be
absent from MMF_INIT_MASK.  This means that the encoding for "MDWE but
without inherit" is different in the prctl than in the mm flags.  This
leads to a bit of bit-mangling in the prctl implementation.

Link: https://lkml.kernel.org/r/20230828150858.393570-6-revest@chromium.org
Signed-off-by: Florent Revest <revest@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ayush Jain <ayush.jain3@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 793838138c ("prctl: Disable prctl(PR_SET_MDWE) on parisc")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-03 07:33:06 +01:00

105 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SCHED_COREDUMP_H
#define _LINUX_SCHED_COREDUMP_H
#include <linux/mm_types.h>
#define SUID_DUMP_DISABLE 0 /* No setuid dumping */
#define SUID_DUMP_USER 1 /* Dump as user of process */
#define SUID_DUMP_ROOT 2 /* Dump as root */
/* mm flags */
/* for SUID_DUMP_* above */
#define MMF_DUMPABLE_BITS 2
#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
extern void set_dumpable(struct mm_struct *mm, int value);
/*
* This returns the actual value of the suid_dumpable flag. For things
* that are using this for checking for privilege transitions, it must
* test against SUID_DUMP_USER rather than treating it as a boolean
* value.
*/
static inline int __get_dumpable(unsigned long mm_flags)
{
return mm_flags & MMF_DUMPABLE_MASK;
}
static inline int get_dumpable(struct mm_struct *mm)
{
return __get_dumpable(mm->flags);
}
/* coredump filter bits */
#define MMF_DUMP_ANON_PRIVATE 2
#define MMF_DUMP_ANON_SHARED 3
#define MMF_DUMP_MAPPED_PRIVATE 4
#define MMF_DUMP_MAPPED_SHARED 5
#define MMF_DUMP_ELF_HEADERS 6
#define MMF_DUMP_HUGETLB_PRIVATE 7
#define MMF_DUMP_HUGETLB_SHARED 8
#define MMF_DUMP_DAX_PRIVATE 9
#define MMF_DUMP_DAX_SHARED 10
#define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
#define MMF_DUMP_FILTER_BITS 9
#define MMF_DUMP_FILTER_MASK \
(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
#define MMF_DUMP_FILTER_DEFAULT \
((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
(1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
# define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
#else
# define MMF_DUMP_MASK_DEFAULT_ELF 0
#endif
/* leave room for more dump flags */
#define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
#define MMF_VM_HUGEPAGE 17 /* set when mm is available for
khugepaged */
/*
* This one-shot flag is dropped due to necessity of changing exe once again
* on NFS restore
*/
//#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
#define MMF_HAS_UPROBES 19 /* has uprobes */
#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
#define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */
#define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */
#define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */
#define MMF_DISABLE_THP 24 /* disable THP for all VMAs */
#define MMF_OOM_REAP_QUEUED 25 /* mm was queued for oom_reaper */
#define MMF_MULTIPROCESS 26 /* mm is shared between processes */
/*
* MMF_HAS_PINNED: Whether this mm has pinned any pages. This can be either
* replaced in the future by mm.pinned_vm when it becomes stable, or grow into
* a counter on its own. We're aggresive on this bit for now: even if the
* pinned pages were unpinned later on, we'll still keep this bit set for the
* lifecycle of this mm, just for simplicity.
*/
#define MMF_HAS_PINNED 27 /* FOLL_PIN has run, never cleared */
#define MMF_HAS_MDWE 28
#define MMF_HAS_MDWE_MASK (1 << MMF_HAS_MDWE)
#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP)
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK)
#define MMF_VM_MERGE_ANY 29
#define MMF_HAS_MDWE_NO_INHERIT 30
static inline unsigned long mmf_init_flags(unsigned long flags)
{
if (flags & (1UL << MMF_HAS_MDWE_NO_INHERIT))
flags &= ~((1UL << MMF_HAS_MDWE) |
(1UL << MMF_HAS_MDWE_NO_INHERIT));
return flags & MMF_INIT_MASK;
}
#endif /* _LINUX_SCHED_COREDUMP_H */