summaryrefslogtreecommitdiffstats
path: root/fs/debugfs/file.c
Commit message (Collapse)AuthorAgeFilesLines
* debugfs: remove return value of debugfs_create_u32()Greg Kroah-Hartman2020-04-171-12/+3
| | | | | | | | | | No one checks the return value of debugfs_create_u32(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20200416145448.GA1380878@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'linus' of ↵Linus Torvalds2020-04-011-0/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "API: - Fix out-of-sync IVs in self-test for IPsec AEAD algorithms Algorithms: - Use formally verified implementation of x86/curve25519 Drivers: - Enhance hwrng support in caam - Use crypto_engine for skcipher/aead/rsa/hash in caam - Add Xilinx AES driver - Add uacce driver - Register zip engine to uacce in hisilicon - Add support for OCTEON TX CPT engine in marvell" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits) crypto: af_alg - bool type cosmetics crypto: arm[64]/poly1305 - add artifact to .gitignore files crypto: caam - limit single JD RNG output to maximum of 16 bytes crypto: caam - enable prediction resistance in HRWNG bus: fsl-mc: add api to retrieve mc version crypto: caam - invalidate entropy register during RNG initialization crypto: caam - check if RNG job failed crypto: caam - simplify RNG implementation crypto: caam - drop global context pointer and init_done crypto: caam - use struct hwrng's .init for initialization crypto: caam - allocate RNG instantiation descriptor with GFP_DMA crypto: ccree - remove duplicated include from cc_aead.c crypto: chelsio - remove set but not used variable 'adap' crypto: marvell - enable OcteonTX cpt options for build crypto: marvell - add the Virtual Function driver for CPT crypto: marvell - add support for OCTEON TX CPT engine crypto: marvell - create common Kconfig and Makefile for Marvell crypto: arm/neon - memzero_explicit aes-cbc key crypto: bcm - Use scnprintf() for avoiding potential buffer overflow crypto: atmel-i2c - Fix wakeup fail ...
| * debugfs: regset32: Add Runtime PM supportGeert Uytterhoeven2020-02-221-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hardware registers of devices under control of power management cannot be accessed at all times. If such a device is suspended, register accesses may lead to undefined behavior, like reading bogus values, or causing exceptions or system lock-ups. Extend struct debugfs_regset32 with an optional field to let device drivers specify the device the registers in the set belong to. This allows debugfs_show_regset32() to make sure the device is resumed while its registers are being read. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* | debugfs: Check module state before warning in {full/open}_proxy_open()Taehee Yoo2020-03-181-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the module is being removed, the module state is set to MODULE_STATE_GOING. At this point, try_module_get() fails. And when {full/open}_proxy_open() is being called, it calls try_module_get() to try to hold module reference count. If it fails, it warns about the possibility of debugfs file leak. If {full/open}_proxy_open() is called while the module is being removed, it fails to hold the module. So, It warns about debugfs file leak. But it is not the debugfs file leak case. So, this patch just adds module state checking routine in the {full/open}_proxy_open(). Test commands: #SHELL1 while : do modprobe netdevsim echo 1 > /sys/bus/netdevsim/new_device modprobe -rv netdevsim done #SHELL2 while : do cat /sys/kernel/debug/netdevsim/netdevsim1/ports/0/ipsec done Splat looks like: [ 298.766738][T14664] debugfs file owner did not clean up at exit: ipsec [ 298.766766][T14664] WARNING: CPU: 2 PID: 14664 at fs/debugfs/file.c:312 full_proxy_open+0x10f/0x650 [ 298.768595][T14664] Modules linked in: netdevsim(-) openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 n][ 298.771343][T14664] CPU: 2 PID: 14664 Comm: cat Tainted: G W 5.5.0+ #1 [ 298.772373][T14664] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 298.773545][T14664] RIP: 0010:full_proxy_open+0x10f/0x650 [ 298.774247][T14664] Code: 48 c1 ea 03 80 3c 02 00 0f 85 c1 04 00 00 49 8b 3c 24 e8 e4 b5 78 ff 84 c0 75 2d 4c 89 ee 48 [ 298.776782][T14664] RSP: 0018:ffff88805b7df9b8 EFLAGS: 00010282[ 298.777583][T14664] RAX: dffffc0000000008 RBX: ffff8880511725c0 RCX: 0000000000000000 [ 298.778610][T14664] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff8880540c5c14 [ 298.779637][T14664] RBP: 0000000000000000 R08: fffffbfff15235ad R09: 0000000000000000 [ 298.780664][T14664] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffffc06b5000 [ 298.781702][T14664] R13: ffff88804c234a88 R14: ffff88804c22dd00 R15: ffffffff8a1b5660 [ 298.782722][T14664] FS: 00007fafa13a8540(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000 [ 298.783845][T14664] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 298.784672][T14664] CR2: 00007fafa0e9cd10 CR3: 000000004b286005 CR4: 00000000000606e0 [ 298.785739][T14664] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 298.786769][T14664] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 298.787785][T14664] Call Trace: [ 298.788237][T14664] do_dentry_open+0x63c/0xf50 [ 298.788872][T14664] ? open_proxy_open+0x270/0x270 [ 298.789524][T14664] ? __x64_sys_fchdir+0x180/0x180 [ 298.790169][T14664] ? inode_permission+0x65/0x390 [ 298.790832][T14664] path_openat+0xc45/0x2680 [ 298.791425][T14664] ? save_stack+0x69/0x80 [ 298.791988][T14664] ? save_stack+0x19/0x80 [ 298.792544][T14664] ? path_mountpoint+0x2e0/0x2e0 [ 298.793233][T14664] ? check_chain_key+0x236/0x5d0 [ 298.793910][T14664] ? sched_clock_cpu+0x18/0x170 [ 298.794527][T14664] ? find_held_lock+0x39/0x1d0 [ 298.795153][T14664] do_filp_open+0x16a/0x260 [ ... ] Fixes: 9fd4dcece43a ("debugfs: prevent access to possibly dead file_operations at file open") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://lore.kernel.org/r/20200218043150.29447-1-ap420073@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | debugfs: remove return value of debugfs_create_regset32()Greg Kroah-Hartman2020-02-101-13/+4
|/ | | | | | | | | 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 <gregkh@linuxfoundation.org>
* debugfs: Return -EPERM when locked downEric Snowberg2020-01-141-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <eric.snowberg@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable <stable@vger.kernel.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20191207161603.35907-1-eric.snowberg@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Fix warnings when building documentationDaniel W. S. Almeida2020-01-061-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | 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 <dwlsalmeida@gmail.com> Link: https://lore.kernel.org/r/20191227010035.854913-1-dwlsalmeida@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_atomic_t()Greg Kroah-Hartman2019-11-031-5/+4
| | | | | | | | | 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 <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_x8()Greg Kroah-Hartman2019-11-021-3/+3
| | | | | | | | | 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 <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_x64()Greg Kroah-Hartman2019-10-161-3/+3
| | | | | | | | | 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 <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_x32()Greg Kroah-Hartman2019-10-161-3/+3
| | | | | | | | | No one checks the return value of debugfs_create_x32(), 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/20191011132931.1186197-7-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_x16()Greg Kroah-Hartman2019-10-161-3/+3
| | | | | | | | | No one checks the return value of debugfs_create_x16(), 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/20191011132931.1186197-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_size_t()Greg Kroah-Hartman2019-10-141-5/+4
| | | | | | | | | | No one checks the return value of debugfs_create_size_t(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_u64()Greg Kroah-Hartman2019-10-141-12/+3
| | | | | | | | | | No one checks the return value of debugfs_create_u64(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_u16()Greg Kroah-Hartman2019-10-141-12/+3
| | | | | | | | | | No one checks the return value of debugfs_create_u16(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: remove return value of debugfs_create_u8()Greg Kroah-Hartman2019-10-141-12/+3
| | | | | | | | | | No one checks the return value of debugfs_create_u8(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20191011132931.1186197-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'next-lockdown' of ↵Linus Torvalds2019-09-281-0/+30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
| * debugfs: Restrict debugfs when the kernel is locked downDavid Howells2019-08-191-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disallow opening of debugfs files that might be used to muck around when the kernel is locked down as various drivers give raw access to hardware through debugfs. Given the effort of auditing all 2000 or so files and manually fixing each one as necessary, I've chosen to apply a heuristic instead. The following changes are made: (1) chmod and chown are disallowed on debugfs objects (though the root dir can be modified by mount and remount, but I'm not worried about that). (2) When the kernel is locked down, only files with the following criteria are permitted to be opened: - The file must have mode 00444 - The file must not have ioctl methods - The file must not have mmap (3) When the kernel is locked down, files may only be opened for reading. Normal device interaction should be done through configfs, sysfs or a miscdev, not debugfs. Note that this makes it unnecessary to specifically lock down show_dsts(), show_devs() and show_call() in the asus-wmi driver. I would actually prefer to lock down all files by default and have the the files unlocked by the creator. This is tricky to manage correctly, though, as there are 19 creation functions and ~1600 call sites (some of them in loops scanning tables). Signed-off-by: David Howells <dhowells@redhat.com> cc: Andy Shevchenko <andy.shevchenko@gmail.com> cc: acpi4asus-user@lists.sourceforge.net cc: platform-driver-x86@vger.kernel.org cc: Matthew Garrett <mjg59@srcf.ucam.org> cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Matthew Garrett <matthewgarrett@google.com> Signed-off-by: James Morris <jmorris@namei.org>
* | debugfs: make debugfs_create_u32_array() return voidGreg Kroah-Hartman2019-06-031-10/+4
|/ | | | | | | | The single user of debugfs_create_u32_array() does not care about the return value of it, so make it return void as there is no need to do anything with the return value. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: update documented return values of debugfs helpersRonald Tschalär2019-04-251-42/+35
| | | | | | | | | | Since commit ff9fb72bc077 ("debugfs: return error values, not NULL") these helper functions do not return NULL anymore (with the exception of debugfs_create_u32_array()). Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Signed-off-by: Ronald Tschalär <ronald@innovation.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Re-use kstrtobool_from_user()Andy Shevchenko2018-05-141-8/+2
| | | | | | | Re-use kstrtobool_from_user() instead of open coded variant. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds2018-02-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use linux/poll.h instead of asm/poll.hAl Viro2018-02-011-1/+1
| | | | | | | | | The only place that has any business including asm/poll.h is linux/poll.h. Fortunately, asm/poll.h had only been included in 3 places beyond that one, and all of them are trivial to switch to using linux/poll.h. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: annotate ->poll() instancesAl Viro2017-11-271-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* anntotate the places where ->poll() return values goAl Viro2017-11-271-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* debugfs: Remove redundant license textGreg Kroah-Hartman2017-11-071-5/+0
| | | | | | | | | | | | | | | | Now that the SPDX tag is in all debugfs files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: add SPDX identifiers to all debugfs filesGreg Kroah-Hartman2017-11-071-0/+1
| | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the debugfs files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: defer debugfs_fsdata allocation to first usageNicolai Stange2017-11-071-9/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, __debugfs_create_file allocates one struct debugfs_fsdata instance for every file created. However, there are potentially many debugfs file around, most of which are never touched by userspace. Thus, defer the allocations to the first usage, i.e. to the first debugfs_file_get(). A dentry's ->d_fsdata starts out to point to the "real", user provided fops. After a debugfs_fsdata instance has been allocated (and the real fops pointer has been moved over into its ->real_fops member), ->d_fsdata is changed to point to it from then on. The two cases are distinguished by setting BIT(0) for the real fops case. struct debugfs_fsdata's foremost purpose is to track active users and to make debugfs_remove() block until they are done. Since no debugfs_fsdata instance means no active users, make debugfs_remove() return immediately in this case. Take care of possible races between debugfs_file_get() and debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata instance and thus wait for possible active users or debugfs_file_get() must see a dead dentry and return immediately. Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether ->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it. Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually a debugfs_fsdata instance before returning it, otherwise emit a warning. The set of possible error codes returned from debugfs_file_get() has grown from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open() pass the -ENOMEM onwards to their callers. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: call debugfs_real_fops() only after debugfs_file_get()Nicolai Stange2017-11-071-3/+4
| | | | | | | | | | | | | | | | | | | The current implementation of debugfs_real_fops() relies on a debugfs_fsdata instance to be installed at ->d_fsdata. With future patches introducing lazy allocation of these, this requirement will be guaranteed to be fullfilled only inbetween a debugfs_file_get()/debugfs_file_put() pair. The full proxies' fops implemented by debugfs happen to be the only offenders. Fix them up by moving their debugfs_real_fops() calls past those to debugfs_file_get(). full_proxy_release() is special as it doesn't invoke debugfs_file_get() at all. Leave it alone for now. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: purge obsolete SRCU based removal protectionNicolai Stange2017-11-071-48/+0
| | | | | | | | | Purge the SRCU based file removal race protection in favour of the new, refcount based debugfs_file_get()/debugfs_file_put() API. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: convert to debugfs_file_get() and -put()Nicolai Stange2017-11-071-56/+50
| | | | | | | | | | Convert all calls to the now obsolete debugfs_use_file_start() and debugfs_use_file_finish() from the debugfs core itself to the new debugfs_file_get() and debugfs_file_put() API. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: debugfs_real_fops(): drop __must_hold sparse annotationNicolai Stange2017-11-071-5/+1
| | | | | | | | | | | | | | Currently, debugfs_real_fops() is annotated with a __must_hold(&debugfs_srcu) sparse annotation. With the conversion of the SRCU based protection of users against concurrent file removals to a per-file refcount based scheme, this becomes wrong. Drop this annotation. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: implement per-file removal protectionNicolai Stange2017-11-071-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 49d200deaa68 ("debugfs: prevent access to removed files' private data"), accesses to a file's private data are protected from concurrent removal by covering all file_operations with a SRCU read section and sychronizing with those before returning from debugfs_remove() by means of synchronize_srcu(). As pointed out by Johannes Berg, there are debugfs files with forever blocking file_operations. Their corresponding SRCU read side sections would block any debugfs_remove() forever as well, even unrelated ones. This results in a livelock. Because a remover can't cancel any indefinite blocking within foreign files, this is a problem. Resolve this by introducing support for more granular protection on a per-file basis. This is implemented by introducing an 'active_users' refcount_t to the per-file struct debugfs_fsdata state. At file creation time, it is set to one and a debugfs_remove() will drop that initial reference. The new debugfs_file_get() and debugfs_file_put(), intended to be used in place of former debugfs_use_file_start() and debugfs_use_file_finish(), increment and decrement it respectively. Once the count drops to zero, debugfs_file_put() will signal a completion which is possibly being waited for from debugfs_remove(). Thus, as long as there is a debugfs_file_get() not yet matched by a corresponding debugfs_file_put() around, debugfs_remove() will block. Actual users of debugfs_use_file_start() and -finish() will get converted to the new debugfs_file_get() and debugfs_file_put() by followup patches. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: add support for more elaborate ->d_fsdataNicolai Stange2017-11-071-0/+12
| | | | | | | | | | | | | | | | | | | Currently, the user provided fops, "real_fops", are stored directly into ->d_fsdata. In order to be able to store more per-file state and thus prepare for more granular file removal protection, wrap the real_fops into a dynamically allocated container struct, debugfs_fsdata. A struct debugfs_fsdata gets allocated at file creation and freed from the newly intoduced ->d_release(). Finally, move the implementation of debugfs_real_fops() out of the public debugfs header such that struct debugfs_fsdata's declaration can be kept private. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: update location of filesystems documentationMauro Carvalho Chehab2017-05-161-1/+1
| | | | | | | The filesystem documentation was moved from DocBook to Documentation/filesystems/. Update it at the sources. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
* debugfs: propagate release() call resultEric Engestrom2016-09-271-1/+1
| | | | | | | | The result was being ignored and 0 was always returned. Return the actual result instead. Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: introduce a public file_operations accessorChristian Lamparter2016-09-211-8/+5
| | | | | | | | | | | | | | | | | | | | This patch introduces an accessor which can be used by the users of debugfs (drivers, fs, ...) to get the original file_operations struct. It also removes the REAL_FOPS_DEREF macro in file.c and converts the code to use the public version. Previously, REAL_FOPS_DEREF was only available within the file.c of debugfs. But having a public getter available for debugfs users is important as some drivers (carl9170 and b43) use the pointer of the original file_operations in conjunction with container_of() within their debugfs implementations. Reviewed-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Cc: stable <stable@vger.kernel.org> # 4.7+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: open_proxy_open(): avoid double fops releaseNicolai Stange2016-06-151-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Debugfs' open_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file_unsafe(), - grabs a reference to the original file_operations instance passed to debugfs_create_file_unsafe() via fops_get(), - installs it at the file's ->f_op by means of replace_fops() - and calls fops_put() on it. Since the semantics of replace_fops() are such that the reference's ownership is transferred, the subsequent fops_put() will result in a double release when the file is eventually closed. Currently, this is not an issue since fops_put() basically does a module_put() on the file_operations' ->owner only and there don't exist any modules calling debugfs_create_file_unsafe() yet. This is expected to change in the future though, c.f. commit c64688081490 ("debugfs: add support for self-protecting attribute file fops"). Remove the call to fops_put() from open_proxy_open(). Fixes: 9fd4dcece43a ("debugfs: prevent access to possibly dead file_operations at file open") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: full_proxy_open(): free proxy on ->open() failureNicolai Stange2016-06-151-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Debugfs' full_proxy_open(), the ->open() installed at all inodes created through debugfs_create_file(), - grabs a reference to the original struct file_operations instance passed to debugfs_create_file(), - dynamically allocates a proxy struct file_operations instance wrapping the original - and installs this at the file's ->f_op. Afterwards, it calls the original ->open() and passes its return value back to the VFS layer. Now, if that return value indicates failure, the VFS layer won't ever call ->release() and thus, neither the reference to the original file_operations nor the memory for the proxy file_operations will get released, i.e. both are leaked. Upon failure of the original fops' ->open(), undo the proxy installation. That is: - Set the struct file ->f_op to what it had been when full_proxy_open() was entered. - Drop the reference to the original file_operations. - Free the memory holding the proxy file_operations. Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: unproxify files created through debugfs_create_u32_array()Nicolai Stange2016-04-121-1/+2
| | | | | | | | | | | | | | | | | The struct file_operations u32_array_fops associated with files created through debugfs_create_u32_array() has been lifetime aware already: everything needed for subsequent operation is copied to a ->f_private buffer at file opening time in u32_array_open(). Now, ->open() is always protected against file removal issues by the debugfs core. There is no need for the debugfs core to wrap the u32_array_fops with a file lifetime managing proxy. Make debugfs_create_u32_array() create its files in non-proxying operation mode by means of debugfs_create_file_unsafe(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: unproxify files created through debugfs_create_blob()Nicolai Stange2016-04-121-3/+10
| | | | | | | | | | | | | | | | | | | Currently, the struct file_operations fops_blob associated with files created through the debugfs_create_blob() helpers are not file lifetime aware. Thus, a lifetime managing proxy is created around fops_blob each time such a file is opened which is an unnecessary waste of resources. Implement file lifetime management for the fops_bool file_operations. Namely, make read_file_blob() safe gainst file removals by means of debugfs_use_file_start() and debugfs_use_file_finish(). Make debugfs_create_blob() create its files in non-proxying operation mode by means of debugfs_create_file_unsafe(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: unproxify files created through debugfs_create_bool()Nicolai Stange2016-04-121-21/+20
| | | | | | | | | | | | | | | | | | | | | | | Currently, the struct file_operations fops_bool associated with files created through the debugfs_create_bool() helpers are not file lifetime aware. Thus, a lifetime managing proxy is created around fops_bool each time such a file is opened which is an unnecessary waste of resources. Implement file lifetime management for the fops_bool file_operations. Namely, make debugfs_read_file_bool() and debugfs_write_file_bool() safe against file removals by means of debugfs_use_file_start() and debugfs_use_file_finish(). Make debugfs_create_bool() create its files in non-proxying operation mode through debugfs_create_mode_unsafe(). Finally, purge debugfs_create_mode() as debugfs_create_bool() had been its last user. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: unproxify integer attribute filesNicolai Stange2016-04-121-48/+75
| | | | | | | | | | | | | | | | | | | | | | | Currently, the struct file_operations associated with the integer attribute style files created through the debugfs_create_*() helpers are not file lifetime aware as they are defined by means of DEFINE_SIMPLE_ATTRIBUTE(). Thus, a lifetime managing proxy is created around the original fops each time such a file is opened which is an unnecessary waste of resources. Migrate all usages of DEFINE_SIMPLE_ATTRIBUTE() within debugfs itself to DEFINE_DEBUGFS_ATTRIBUTE() in order to implement file lifetime managing within the struct file_operations thus defined. Introduce the debugfs_create_mode_unsafe() helper, analogous to debugfs_create_mode(), but distinct in that it creates the files in non-proxying operation mode through debugfs_create_file_unsafe(). Feed all struct file_operations migrated to DEFINE_DEBUGFS_ATTRIBUTE() into debugfs_create_mode_unsafe() instead of former debugfs_create_mode(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: add support for self-protecting attribute file fopsNicolai Stange2016-04-121-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to protect them against file removal issues, debugfs_create_file() creates a lifetime managing proxy around each struct file_operations handed in. In cases where this struct file_operations is able to manage file lifetime by itself already, the proxy created by debugfs is a waste of resources. The most common class of struct file_operations given to debugfs are those defined by means of the DEFINE_SIMPLE_ATTRIBUTE() macro. Introduce a DEFINE_DEBUGFS_ATTRIBUTE() macro to allow any struct file_operations of this class to be easily made file lifetime aware and thus, to be operated unproxied. Specifically, introduce debugfs_attr_read() and debugfs_attr_write() which wrap simple_attr_read() and simple_attr_write() under the protection of a debugfs_use_file_start()/debugfs_use_file_finish() pair. Make DEFINE_DEBUGFS_ATTRIBUTE() set the defined struct file_operations' ->read() and ->write() members to these wrappers. Export debugfs_create_file_unsafe() in order to allow debugfs users to create their files in non-proxying operation mode. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: prevent access to removed files' private dataNicolai Stange2016-04-121-2/+155
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Upon return of debugfs_remove()/debugfs_remove_recursive(), it might still be attempted to access associated private file data through previously opened struct file objects. If that data has been freed by the caller of debugfs_remove*() in the meanwhile, the reading/writing process would either encounter a fault or, if the memory address in question has been reassigned again, unrelated data structures could get overwritten. However, since debugfs files are seldomly removed, usually from module exit handlers only, the impact is very low. Currently, there are ~1000 call sites of debugfs_create_file() spread throughout the whole tree and touching all of those struct file_operations in order to make them file removal aware by means of checking the result of debugfs_use_file_start() from within their methods is unfeasible. Instead, wrap the struct file_operations by a lifetime managing proxy at file open: - In debugfs_create_file(), the original fops handed in has got stashed away in ->d_fsdata already. - In debugfs_create_file(), install a proxy file_operations factory, debugfs_full_proxy_file_operations, at ->i_fop. This proxy factory has got an ->open() method only. It carries out some lifetime checks and if successful, dynamically allocates and sets up a new struct file_operations proxy at ->f_op. Afterwards, it forwards to the ->open() of the original struct file_operations in ->d_fsdata, if any. The dynamically set up proxy at ->f_op has got a lifetime managing wrapper set for each of the methods defined in the original struct file_operations in ->d_fsdata. Its ->release()er frees the proxy again and forwards to the original ->release(), if any. In order not to mislead the VFS layer, it is strictly necessary to leave those fields blank in the proxy that have been NULL in the original struct file_operations also, i.e. aren't supported. This is why there is a need for dynamically allocated proxies. The choice made not to allocate a proxy instance for every dentry at file creation, but for every struct file object instantiated thereof is justified by the expected usage pattern of debugfs, namely that in general very few files get opened more than once at a time. The wrapper methods set in the struct file_operations implement lifetime managing by means of the SRCU protection facilities already in place for debugfs: They set up a SRCU read side critical section and check whether the dentry is still alive by means of debugfs_use_file_start(). If so, they forward the call to the original struct file_operation stored in ->d_fsdata, still under the protection of the SRCU read side critical section. This SRCU read side critical section prevents any pending debugfs_remove() and friends to return to their callers. Since a file's private data must only be freed after the return of debugfs_remove(), the ongoing proxied call is guarded against any file removal race. If, on the other hand, the initial call to debugfs_use_file_start() detects that the dentry is dead, the wrapper simply returns -EIO and does not forward the call. Note that the ->poll() wrapper is special in that its signature does not allow for the return of arbitrary -EXXX values and thus, POLLHUP is returned here. In order not to pollute debugfs with wrapper definitions that aren't ever needed, I chose not to define a wrapper for every struct file_operations method possible. Instead, a wrapper is defined only for the subset of methods which are actually set by any debugfs users. Currently, these are: ->llseek() ->read() ->write() ->unlocked_ioctl() ->poll() The ->release() wrapper is special in that it does not protect the original ->release() in any way from dead files in order not to leak resources. Thus, any ->release() handed to debugfs must implement file lifetime management manually, if needed. For only 33 out of a total of 434 releasers handed in to debugfs, it could not be verified immediately whether they access data structures that might have been freed upon a debugfs_remove() return in the meanwhile. Export debugfs_use_file_start() and debugfs_use_file_finish() in order to allow any ->release() to manually implement file lifetime management. For a set of common cases of struct file_operations implemented by the debugfs_core itself, future patches will incorporate file lifetime management directly within those in order to allow for their unproxied operation. Rename the original, non-proxying "debugfs_create_file()" to "debugfs_create_file_unsafe()" and keep it for future internal use by debugfs itself. Factor out code common to both into the new __debugfs_create_file(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: prevent access to possibly dead file_operations at file openNicolai Stange2016-04-121-1/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nothing prevents a dentry found by path lookup before a return of __debugfs_remove() to actually get opened after that return. Now, after the return of __debugfs_remove(), there are no guarantees whatsoever regarding the memory the corresponding inode's file_operations object had been kept in. Since __debugfs_remove() is seldomly invoked, usually from module exit handlers only, the race is hard to trigger and the impact is very low. A discussion of the problem outlined above as well as a suggested solution can be found in the (sub-)thread rooted at http://lkml.kernel.org/g/20130401203445.GA20862@ZenIV.linux.org.uk ("Yet another pipe related oops.") Basically, Greg KH suggests to introduce an intermediate fops and Al Viro points out that a pointer to the original ones may be stored in ->d_fsdata. Follow this line of reasoning: - Add SRCU as a reverse dependency of DEBUG_FS. - Introduce a srcu_struct object for the debugfs subsystem. - In debugfs_create_file(), store a pointer to the original file_operations object in ->d_fsdata. - Make debugfs_remove() and debugfs_remove_recursive() wait for a SRCU grace period after the dentry has been delete()'d and before they return to their callers. - Introduce an intermediate file_operations object named "debugfs_open_proxy_file_operations". It's ->open() functions checks, under the protection of a SRCU read lock, whether the dentry is still alive, i.e. has not been d_delete()'d and if so, tries to acquire a reference on the owning module. On success, it sets the file object's ->f_op to the original file_operations and forwards the ongoing open() call to the original ->open(). - For clarity, rename the former debugfs_file_operations to debugfs_noop_file_operations -- they are in no way canonical. The choice of SRCU over "normal" RCU is justified by the fact, that the former may also be used to protect ->i_private data from going away during the execution of a file's readers and writers which may (and do) sleep. Finally, introduce the fs/debugfs/internal.h header containing some declarations internal to the debugfs implementation. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Add debugfs_create_ulong()Viresh Kumar2015-10-181-0/+48
| | | | | | | | | Add debugfs_create_ulong() for the users of type 'unsigned long'. These will be 32 bits long on a 32 bit machine and 64 bits long on a 64 bit machine. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Add read-only/write-only bool file opsStephen Boyd2015-10-171-1/+14
| | | | | | | | | | | | There aren't any read-only or write-only bool file ops, but there is a caller of debugfs_create_bool() that calls it with mode equal to 0400. This leads to the possibility of userspace modifying the file, so let's use the newly created debugfs_create_mode() helper here to fix this. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Add read-only/write-only size_t file opsStephen Boyd2015-10-171-1/+4
| | | | | | | | | | | | There aren't any read-only or write-only size_t file ops, but there is a caller of debugfs_create_size_t() that calls it with mode equal to 0400. This leads to the possibility of userspace modifying the file, so let's use the newly created debugfs_create_mode() helper here to fix this. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* debugfs: Add read-only/write-only x64 file opsStephen Boyd2015-10-171-1/+4
| | | | | | | | | | | | There aren't any read-only or write-only x64 file ops, but there is a caller of debugfs_create_x64() that calls it with mode equal to S_IRUGO. This leads to the possibility of userspace modifying the file, so let's use the newly created debugfs_create_mode() helper here to fix this. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-28 19:46:32 +0000