linux/fs/debugfs, branch v5.6

debugfs: remove return value of debugfs_create_regset32()

2020-02-10T21:00:06Z

No one checks the return value of debugfs_create_regset32(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191122104453.GA2017837@kroah.com Signed-off-by: Greg Kroah-Hartman

Merge branch 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-02-05T05:09:46Z

Pull vfs recursive removal updates from Al Viro: "We have quite a few places where synthetic filesystems do an equivalent of 'rm -rf', with varying amounts of code duplication, wrong locking, etc. That really ought to be a library helper. Only debugfs (and very similar tracefs) are converted here - I have more conversions, but they'd never been in -next, so they'll have to wait" * 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems

debugfs: Return -EPERM when locked down

2020-01-14T15:14:48Z

When lockdown is enabled, debugfs_is_locked_down returns 1. It will then trigger the following: WARNING: CPU: 48 PID: 3747 CPU: 48 PID: 3743 Comm: bash Not tainted 5.4.0-1946.x86_64 #1 Hardware name: Oracle Corporation ORACLE SERVER X7-2/ASM, MB, X7-2, BIOS 41060400 05/20/2019 RIP: 0010:do_dentry_open+0x343/0x3a0 Code: 00 40 08 00 45 31 ff 48 c7 43 28 40 5b e7 89 e9 02 ff ff ff 48 8b 53 28 4c 8b 72 70 4d 85 f6 0f 84 10 fe ff ff e9 f5 fd ff ff <0f> 0b 41 bf ea ff ff ff e9 3b ff ff ff 41 bf e6 ff ff ff e9 b4 fe RSP: 0018:ffffb8740dde7ca0 EFLAGS: 00010202 RAX: ffffffff89e88a40 RBX: ffff928c8e6b6f00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff928dbfd97778 RDI: ffff9285cff685c0 RBP: ffffb8740dde7cc8 R08: 0000000000000821 R09: 0000000000000030 R10: 0000000000000057 R11: ffffb8740dde7a98 R12: ffff926ec781c900 R13: ffff928c8e6b6f10 R14: ffffffff8936e190 R15: 0000000000000001 FS: 00007f45f6777740(0000) GS:ffff928dbfd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff95e0d5d8 CR3: 0000001ece562006 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: vfs_open+0x2d/0x30 path_openat+0x2d4/0x1680 ? tty_mode_ioctl+0x298/0x4c0 do_filp_open+0x93/0x100 ? strncpy_from_user+0x57/0x1b0 ? __alloc_fd+0x46/0x150 do_sys_open+0x182/0x230 __x64_sys_openat+0x20/0x30 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x170/0x1d5 RIP: 0033:0x7f45f5e5ce02 Code: 25 00 00 41 00 3d 00 00 41 00 74 4c 48 8d 05 25 59 2d 00 8b 00 85 c0 75 6d 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 0f 87 a2 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 RSP: 002b:00007fff95e0d2e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000561178c069b0 RCX: 00007f45f5e5ce02 RDX: 0000000000000241 RSI: 0000561178c08800 RDI: 00000000ffffff9c RBP: 00007fff95e0d3e0 R08: 0000000000000020 R09: 0000000000000005 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000001 R15: 0000561178c08800 Change the return type to int and return -EPERM when lockdown is enabled to remove the warning above. Also rename debugfs_is_locked_down to debugfs_locked_down to make it sound less like it returns a boolean. Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down") Signed-off-by: Eric Snowberg Reviewed-by: Matthew Wilcox (Oracle) Cc: stable Acked-by: James Morris Link: https://lore.kernel.org/r/20191207161603.35907-1-eric.snowberg@oracle.com Signed-off-by: Greg Kroah-Hartman

debugfs: Fix warnings when building documentation

2020-01-06T19:35:37Z

Fix the following warnings: fs/debugfs/inode.c:423: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:502: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:534: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:627: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:496: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:502: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:581: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:587: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:846: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:852: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:899: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:905: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:1091: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:1097: WARNING: Inline literal start-string without end-string By replacing %ERR_PTR with ERR_PTR. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/20191227010035.854913-1-dwlsalmeida@gmail.com Signed-off-by: Greg Kroah-Hartman

simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems

2019-12-11T03:29:58Z

two requirements: no file creations in IS_DEADDIR and no cross-directory renames whatsoever. Signed-off-by: Al Viro

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2019-12-06T17:06:58Z

Pull vfs d_inode/d_flags memory ordering fixes from Al Viro: "Fallout from tree-wide audit for ->d_inode/->d_flags barriers use. Basically, the problem is that negative pinned dentries require careful treatment - unless ->d_lock is locked or parent is held at least shared, another thread can make them positive right under us. Most of the uses turned out to be safe - the main surprises as far as filesystems are concerned were - race in dget_parent() fastpath, that might end up with the caller observing the returned dentry _negative_, due to insufficient barriers. It is positive in memory, but we could end up seeing the wrong value of ->d_inode in CPU cache. Fixed. - manual checks that result of lookup_one_len_unlocked() is positive (and rejection of negatives). Again, insufficient barriers (we might end up with inconsistent observed values of ->d_inode and ->d_flags). Fixed by switching to a new primitive that does the checks itself and returns ERR_PTR(-ENOENT) instead of a negative dentry. That way we get rid of boilerplate converting negatives into ERR_PTR(-ENOENT) in the callers and have a single place to deal with the barrier-related mess - inside fs/namei.c rather than in every caller out there. The guts of pathname resolution *do* need to be careful - the race found by Ritesh is real, as well as several similar races. Fortunately, it turns out that we can take care of that with fairly local changes in there. The tree-wide audit had not been fun, and I hate the idea of repeating it. I think the right approach would be to annotate the places where we are _not_ guaranteed ->d_inode/->d_flags stability and have sparse catch regressions. But I'm still not sure what would be the least invasive way of doing that and it's clearly the next cycle fodder" * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/namei.c: fix missing barriers when checking positivity fix dget_parent() fastpath race new helper: lookup_positive_unlocked() fs/namei.c: pull positivity check into follow_managed()

new helper: lookup_positive_unlocked()

2019-11-15T18:49:04Z

Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway. Signed-off-by: Al Viro

debugfs: remove return value of debugfs_create_atomic_t()

2019-11-03T13:03:01Z

No one checks the return value of debugfs_create_atomic_t(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191016130332.GA28240@kroah.com Signed-off-by: Greg Kroah-Hartman

debugfs: remove return value of debugfs_create_x8()

2019-11-02T17:09:12Z

No one checks the return value of debugfs_create_x8(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

debugfs: remove return value of debugfs_create_x64()

2019-10-16T13:07:56Z

No one checks the return value of debugfs_create_x64(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20191011132931.1186197-8-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman