kernel/linux.git/include/linux/syscalls.h, branch v6.12.80

fhandle: expose u64 mount id to name_to_handle_at(2)

2024-09-05T09:39:17+00:00

Now that we provide a unique 64-bit mount ID interface in statx(2), we can now provide a race-free way for name_to_handle_at(2) to provide a file handle and corresponding mount without needing to worry about racing with /proc/mountinfo parsing or having to open a file just to do statx(2). While this is not necessary if you are using AT_EMPTY_PATH and don't care about an extra statx(2) call, users that pass full paths into name_to_handle_at(2) need to know which mount the file handle comes from (to make sure they don't try to open_by_handle_at a file handle from a different filesystem) and switching to AT_EMPTY_PATH would require allocating a file for every name_to_handle_at(2) call, turning err = name_to_handle_at(-EBADF, "/foo/bar/baz", &handle, &mntid, AT_HANDLE_MNT_ID_UNIQUE); into int fd = openat(-EBADF, "/foo/bar/baz", O_PATH | O_CLOEXEC); err1 = name_to_handle_at(fd, "", &handle, &unused_mntid, AT_EMPTY_PATH); err2 = statx(fd, "", AT_EMPTY_PATH, STATX_MNT_ID_UNIQUE, &statxbuf); mntid = statxbuf.stx_mnt_id; close(fd); Reviewed-by: Jeff Layton Signed-off-by: Aleksa Sarai Link: https://lore.kernel.org/r/20240828-exportfs-u64-mount-id-v3-2-10c2c4c16708@cyphar.com Reviewed-by: Jan Kara Reviewed-by: Josef Bacik Signed-off-by: Christian Brauner

Merge tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-07-18T19:19:20+00:00

Pull probes updates from Masami Hiramatsu: "Uprobes: - x86/shstk: Make return uprobe work with shadow stack - Add uretprobe syscall which speeds up the uretprobe 10-30% faster. This syscall is automatically used from user-space trampolines which are generated by the uretprobe. If this syscall is used by normal user program, it will cause SIGILL. Note that this is currently only implemented on x86_64. (This also has two fixes for adjusting the syscall number to avoid conflict with new *attrat syscalls.) - uprobes/perf: fix user stack traces in the presence of pending uretprobe. This corrects the uretprobe's trampoline address in the stacktrace with correct return address - selftests/x86: Add a return uprobe with shadow stack test - selftests/bpf: Add uretprobe syscall related tests. - test case for register integrity check - test case with register changing case - test case for uretprobe syscall without uprobes (expected to fail) - test case for uretprobe with shadow stack - selftests/bpf: add test validating uprobe/uretprobe stack traces - MAINTAINERS: Add uprobes entry. This does not specify the tree but to clarify who maintains and reviews the uprobes Kprobes: - tracing/kprobes: Test case cleanups. Replace redundant WARN_ON_ONCE() + pr_warn() with WARN_ONCE() and remove unnecessary code from selftest - tracing/kprobes: Add symbol counting check when module loads. This checks the uniqueness of the probed symbol on modules. The same check has already done for kernel symbols (This also has a fix for build error with CONFIG_MODULES=n) Cleanup: - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples" * tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: MAINTAINERS: Add uprobes entry selftests/bpf: Change uretprobe syscall number in uprobe_syscall test uprobe: Change uretprobe syscall scope and number tracing/kprobes: Fix build error when find_module() is not available tracing/kprobes: Add symbol counting check when module loads selftests/bpf: add test validating uprobe/uretprobe stack traces perf,uprobes: fix user stack traces in the presence of pending uretprobes tracing/kprobe: Remove cleanup code unrelated to selftest tracing/kprobe: Integrate test warnings into WARN_ONCE selftests/bpf: Add uretprobe shadow stack test selftests/bpf: Add uretprobe syscall call from user space test selftests/bpf: Add uretprobe syscall test for regs changes selftests/bpf: Add uretprobe syscall test for regs integrity selftests/x86: Add return uprobe shadow stack test uprobe: Add uretprobe syscall to speed up return probe uprobe: Wire up uretprobe system call x86/shstk: Make return uprobe work with shadow stack samples: kprobes: add missing MODULE_DESCRIPTION() macros fprobe: add missing MODULE_DESCRIPTION() macro

syscalls: fix sys_fanotify_mark prototype

2024-07-01T12:52:12+00:00

My earlier fix missed an incorrect function prototype that shows up on native 32-bit builds: In file included from fs/notify/fanotify/fanotify_user.c:14: include/linux/syscalls.h:248:25: error: conflicting types for 'sys_fanotify_mark'; have 'long int(int, unsigned int, u32, u32, int, const char *)' {aka 'long int(int, unsigned int, unsigned int, unsigned int, int, const char *)'} 1924 | SYSCALL32_DEFINE6(fanotify_mark, | ^~~~~~~~~~~~~~~~~ include/linux/syscalls.h:862:17: note: previous declaration of 'sys_fanotify_mark' with type 'long int(int, unsigned int, u64, int, const char *)' {aka 'long int(int, unsigned int, long long unsigned int, int, const char *)'} On x86 and powerpc, the prototype is also wrong but hidden in an #ifdef, so it never caused problems. Add another alternative declaration that matches the conditional function definition. Fixes: 403f17a33073 ("parisc: use generic sys_fanotify_mark implementation") Cc: stable@vger.kernel.org Reported-by: Guenter Roeck Reported-by: Geert Uytterhoeven Reported-by: kernel test robot Signed-off-by: Arnd Bergmann

linux/syscalls.h: add missing __user annotations

2024-06-25T13:57:38+00:00

A couple of declarations in linux/syscalls.h are missing __user annotations on their pointers, which can lead to warnings from sparse because these don't match the implementation that have the correct address space annotations. Signed-off-by: Arnd Bergmann

ftruncate: pass a signed offset

2024-06-24T16:29:20+00:00

The old ftruncate() syscall, using the 32-bit off_t misses a sign extension when called in compat mode on 64-bit architectures. As a result, passing a negative length accidentally succeeds in truncating to file size between 2GiB and 4GiB. Changing the type of the compat syscall to the signed compat_off_t changes the behavior so it instead returns -EINVAL. The native entry point, the truncate() syscall and the corresponding loff_t based variants are all correct already and do not suffer from this mistake. Fixes: 3f6d078d4acc ("fix compat truncate/ftruncate") Reviewed-by: Christian Brauner Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann

uprobe: Wire up uretprobe system call

2024-06-11T23:44:27+00:00

Wiring up uretprobe system call, which comes in following changes. We need to do the wiring before, because the uretprobe implementation needs the syscall number. Note at the moment uretprobe syscall is supported only for native 64-bit process. Link: https://lore.kernel.org/all/20240611112158.40795-3-jolsa@kernel.org/ Reviewed-by: Oleg Nesterov Reviewed-by: Masami Hiramatsu (Google) Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Masami Hiramatsu (Google)

mseal: add mseal syscall

2024-05-24T02:40:26+00:00

The new mseal() is an syscall on 64 bit CPU, and with following signature: int mseal(void addr, size_t len, unsigned long flags) addr/len: memory range. flags: reserved. mseal() blocks following operations for the given memory range. 1> Unmapping, moving to another location, and shrinking the size, via munmap() and mremap(), can leave an empty space, therefore can be replaced with a VMA with a new set of attributes. 2> Moving or expanding a different VMA into the current location, via mremap(). 3> Modifying a VMA via mmap(MAP_FIXED). 4> Size expansion, via mremap(), does not appear to pose any specific risks to sealed VMAs. It is included anyway because the use case is unclear. In any case, users can rely on merging to expand a sealed VMA. 5> mprotect() and pkey_mprotect(). 6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous memory, when users don't have write permission to the memory. Those behaviors can alter region contents by discarding pages, effectively a memset(0) for anonymous memory. Following input during RFC are incooperated into this patch: Jann Horn: raising awareness and providing valuable insights on the destructive madvise operations. Linus Torvalds: assisting in defining system call signature and scope. Liam R. Howlett: perf optimization. Theo de Raadt: sharing the experiences and insight gained from implementing mimmutable() in OpenBSD. Finally, the idea that inspired this patch comes from Stephen Röttger's work in Chrome V8 CFI. [jeffxu@chromium.org: add branch prediction hint, per Pedro] Link: https://lkml.kernel.org/r/20240423192825.1273679-2-jeffxu@chromium.org Link: https://lkml.kernel.org/r/20240415163527.626541-3-jeffxu@chromium.org Signed-off-by: Jeff Xu Reviewed-by: Kees Cook Reviewed-by: Liam R. Howlett Cc: Pedro Falcato Cc: Dave Hansen Cc: Greg Kroah-Hartman Cc: Guenter Roeck Cc: Jann Horn Cc: Jeff Xu Cc: Jonathan Corbet Cc: Jorge Lucangeli Obes Cc: Linus Torvalds Cc: Matthew Wilcox (Oracle) Cc: Muhammad Usama Anjum Cc: Pedro Falcato Cc: Stephen Röttger Cc: Suren Baghdasaryan Cc: Amer Al Shanawany Cc: Javier Carrasco Cc: Shuah Khan Signed-off-by: Andrew Morton

lsm: use 32-bit compatible data types in LSM syscalls

2024-03-14T15:31:26+00:00

Change the size parameters in lsm_list_modules(), lsm_set_self_attr() and lsm_get_self_attr() from size_t to u32. This avoids the need to have different interfaces for 32 and 64 bit systems. Cc: stable@vger.kernel.org Fixes: a04a1198088a ("LSM: syscalls for current process attributes") Fixes: ad4aff9ec25f ("LSM: Create lsm_list_modules system call") Signed-off-by: Casey Schaufler Reported-and-reviewed-by: Dmitry V. Levin [PM: subject and metadata tweaks, syscall.h fixes] Signed-off-by: Paul Moore

x86/entry/ia32: Ensure s32 is sign extended to s64

2024-01-24T10:49:19+00:00

Presently ia32 registers stored in ptregs are unconditionally cast to unsigned int by the ia32 stub. They are then cast to long when passed to __se_sys*, but will not be sign extended. This takes the sign of the syscall argument into account in the ia32 stub. It still casts to unsigned int to avoid implementation specific behavior. However then casts to int or unsigned int as necessary. So that the following cast to long sign extends the value. This fixes the io_pgetevents02 LTP test when compiled with -m32. Presently the systemcall io_pgetevents_time64() unexpectedly accepts -1 for the maximum number of events. It doesn't appear other systemcalls with signed arguments are effected because they all have compat variants defined and wired up. Fixes: ebeb8c82ffaf ("syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32") Suggested-by: Arnd Bergmann Signed-off-by: Richard Palethorpe Signed-off-by: Nikolay Borisov Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240110130122.3836513-1-nik.borisov@suse.com Link: https://lore.kernel.org/ltp/20210921130127.24131-1-rpalethorpe@suse.com/

fs: rework listmount() implementation

2024-01-13T12:06:25+00:00

Linus pointed out that there's error handling and naming issues in the that we should rewrite: * Perform the access checks for the buffer before actually doing any work instead of doing it during the iteration. * Rename the arguments to listmount() and do_listmount() to clarify what the arguments are used for. * Get rid of the pointless ctr variable and overflow checking. * Get rid of the pointless speculation check. Link: https://lore.kernel.org/r/CAHk-=wjh6Cypo8WC-McXgSzCaou3UXccxB+7PVeSuGR8AjCphg@mail.gmail.com Suggested-by: Linus Torvalds Signed-off-by: Christian Brauner