- 08 Oct, 2021 2 commits
-
-
Steven Rostedt (VMware) authored
When building the files in the tracefs file system, do not by default set any permissions for OTH (other). This will make it easier for admins who want to define a group for accessing tracefs and not having to first disable all the permission bits for "other" in the file system. As tracing can leak sensitive information, it should never by default allowing all users access. An admin can still set the permission bits for others to have access, which may be useful for creating a honeypot and seeing who takes advantage of it and roots the machine. Link: https://lkml.kernel.org/r/20210818153038.864149276@goodmis.orgSigned-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
-
Steven Rostedt (VMware) authored
The tracefs file system is by default mounted such that only root user can access it. But there are legitimate reasons to create a group and allow those added to the group to have access to tracing. By changing the permissions of the tracefs mount point to allow access, it will allow group access to the tracefs directory. There should not be any real reason to allow all access to the tracefs directory as it contains sensitive information. Have the default permission of directories being created not have any OTH (other) bits set, such that an admin that wants to give permission to a group has to first disable all OTH bits in the file system. Link: https://lkml.kernel.org/r/20210818153038.664127804@goodmis.orgSigned-off-by:
-
- 07 Oct, 2021 1 commit
-
-
Steven Rostedt (VMware) authored
The upper and lower variables are set as link lists to add into the sparse array. If they are NULL, after the needed allocations are done, then there is nothing to add. But they need to be initialized to NULL for this to work. Link: https://lore.kernel.org/all/221bc7ba-a475-1cb9-1bbe-730bb9c2d448@canonical.com/ Fixes: 8d6e9098 ("tracing: Create a sparse bitmask for pid filtering") Reported-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
-
- 05 Oct, 2021 2 commits
-
-
Steven Rostedt (VMware) authored
When the trace_pid_list was created, the default pid max was 32768. Creating a bitmask that can hold one bit for all 32768 took up 4096 (one page). Having a one page bitmask was not much of a problem, and that was used for mapping pids. But today, systems are bigger and can run more tasks, and now the default pid_max is usually set to 4194304. Which means to handle that many pids requires 524288 bytes. Worse yet, the pid_max can be set to 2^30 (1073741824 or 1G) which would take 134217728 (128M) of memory to store this array. Since the pid_list array is very sparsely populated, it is a huge waste of memory to store all possible bits for each pid when most will not be set. Instead, use a page table scheme to store the array, and allow this to handle up to 30 bit pids. The pid_mask will start out with 256 entries for the first 8 MSB bits. This will cost 1K for 32 bit architectures and 2K for 64 bit. Each of these will have a 256 array to store the next 8 bits of the pid (another 1 or 2K). These will hold an 2K byte bitmask (which will cover the LSB 14 bits or 16384 pids). When the trace_pid_list is allocated, it will have the 1/2K upper bits allocated, and then it will allocate a cache for the next upper chunks and the lower chunks (default 6 of each). Then when a bit is "set", these chunks will be pulled from the free list and added to the array. If the free list gets down to a lever (default 2), it will trigger an irqwork that will refill the cache back up. On clearing a bit, if the clear causes the bitmask to be zero, that chunk will then be placed back into the free cache for later use, keeping the need to allocate more down to a minimum. Signed-off-by: -
Steven Rostedt (VMware) authored
Instead of having the logic that does trace_pid_list open coded, wrap it in abstract functions. This will allow a rewrite of the logic that implements the trace_pid_list without affecting the users. Note, this causes a change in behavior. Every time a pid is written into the set_*_pid file, it creates a new list and uses RCU to update it. If pid_max is lowered, but there was a pid currently in the list that was higher than pid_max, those pids will now be removed on updating the list. The old behavior kept that from happening. The rewrite of the pid_list logic will no longer depend on pid_max, and will return the old behavior. Signed-off-by:
-
- 01 Oct, 2021 27 commits
-
-
Masami Hiramatsu authored
In x86, the fake return address on the stack saved by __kretprobe_trampoline() will be replaced with the real return address after returning from trampoline_handler(). Before fixing the return address, the real return address can be found in the 'current->kretprobe_instances'. However, since there is a window between updating the 'current->kretprobe_instances' and fixing the address on the stack, if an interrupt happens at that timing and the interrupt handler does stacktrace, it may fail to unwind because it can not get the correct return address from 'current->kretprobe_instances'. This will eliminate that window by fixing the return address right before updating 'current->kretprobe_instances'. Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2Signed-off-by:
Masami Hiramatsu <mhiramat@kernel.org> Tested-by:
Andrii Nakryiko <andrii@kernel.org> Signed-off-by:
-
Masami Hiramatsu authored
ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the kretprobe_trampoline, but the modified address by kretprobe should be only kretprobe_trampoline+0. Link: https://lkml.kernel.org/r/163163056044.489837.794883849706638013.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, x86 unwinders can not continue the stack unwinding at that point, or record kretprobe_trampoline instead of correct return address. To fix this issue, find the correct return address from task's kretprobe_instances as like as function-graph tracer does. With this fix, the unwinder can correctly unwind the stack from kretprobe event on x86, as below. <...>-135 [003] ...1 6.722338: r_full_proxy_read_0: (vfs_read+0xab/0x1a0 <- full_proxy_read) <...>-135 [003] ...1 6.722377: <stack trace> => kretprobe_trace_func+0x209/0x2f0 => kretprobe_dispatcher+0x4a/0x70 => __kretprobe_trampoline_handler+0xca/0x150 => trampoline_handler+0x44/0x70 => kretprobe_trampoline+0x2a/0x50 => vfs_read+0xab/0x1a0 => ksys_read+0x5f/0xe0 => do_syscall_64+0x33/0x40 => entry_SYSCALL_64_after_hwframe+0x44/0xae Link: https://lkml.kernel.org/r/163163055130.489837.5161749078833497255.stgit@devnote2Reported-by:Daniel Xu <dxu@dxuuu.xyz> Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> Tested-by:
-
Masami Hiramatsu authored
Change __kretprobe_trampoline() to push the address of the __kretprobe_trampoline() as a fake return address at the bottom of the stack frame. This fake return address will be replaced with the correct return address in the trampoline_handler(). With this change, the ORC unwinder can check whether the return address is modified by kretprobes or not. Link: https://lkml.kernel.org/r/163163054185.489837.14338744048957727386.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Since the ORC unwinder from pt_regs requires setting up regs->ip correctly, set the correct return address to the regs->ip before calling user kretprobe handler. This allows the kretrprobe handler to trace stack from the kretprobe's pt_regs by stack_trace_save_regs() (eBPF will do this), instead of stack tracing from the handler context by stack_trace_save() (ftrace will do this). Link: https://lkml.kernel.org/r/163163053237.489837.4272653874525136832.stgit@devnote2Suggested-by:
-
Masami Hiramatsu authored
Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the stack, 'regs->ARM_pc' (instruction pointer) is not accessible from the kretprobe handler. This means if instruction_pointer_set() is used from kretprobe handler, it will break the data on the stack. Make space for instruction pointer (ARM_pc) on the stack in the __kretprobe_trampoline() for fixing this problem. Link: https://lkml.kernel.org/r/163163052262.489837.10327621053231461255.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Add instruction_pointer_set() API for ia64. Link: https://lkml.kernel.org/r/163163051195.489837.1039597819838213481.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Add instruction_pointer_set() API for arc. Link: https://lkml.kernel.org/r/163163050148.489837.15187799269793560256.stgit@devnote2Signed-off-by:
-
Josh Poimboeuf authored
Add UNWIND_HINT_FUNC on __kretprobe_trampoline() code so that ORC information is generated on the __kretprobe_trampoline() correctly. Also, this uses STACK_FRAME_NON_STANDARD_FP(), CONFIG_FRAME_POINTER- -specific version of STACK_FRAME_NON_STANDARD(). Link: https://lkml.kernel.org/r/163163049242.489837.11970969750993364293.stgit@devnote2Signed-off-by:
-
Josh Poimboeuf authored
If a function is ignored, also ignore its hints. This is useful for the case where the function ignore is conditional on frame pointers, e.g. STACK_FRAME_NON_STANDARD_FP(). Link: https://lkml.kernel.org/r/163163048317.489837.10988954983369863209.stgit@devnote2Signed-off-by:
-
Josh Poimboeuf authored
Add a CONFIG_FRAME_POINTER-specific version of STACK_FRAME_NON_STANDARD() for the case where a function is intentionally missing frame pointer setup, but otherwise needs objtool/ORC coverage when frame pointers are disabled. Link: https://lkml.kernel.org/r/163163047364.489837.17377799909553689661.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Introduce kretprobe_find_ret_addr() and is_kretprobe_trampoline(). These APIs will be used by the ORC stack unwinder and ftrace, so that they can check whether the given address points kretprobe trampoline code and query the correct return address in that case. Link: https://lkml.kernel.org/r/163163046461.489837.1044778356430293962.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Since now there is kretprobe_trampoline_addr() for referring the address of kretprobe trampoline code, we don't need to access kretprobe_trampoline directly. Make it harder to refer by renaming it to __kretprobe_trampoline(). Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2Suggested-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
-
Masami Hiramatsu authored
The __kretprobe_trampoline_handler() callback, called from low level arch kprobes methods, has the 'trampoline_address' parameter, which is entirely superfluous as it basically just replicates: dereference_kernel_function_descriptor(kretprobe_trampoline) In fact we had bugs in arch code where it wasn't replicated correctly. So remove this superfluous parameter and use kretprobe_trampoline_addr() instead. Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
~15 years ago kprobes grew the 'arch_deref_entry_point()' __weak function: 3d7e3382: ("jprobes: make jprobes a little safer for users") But this is just open-coded dereference_symbol_descriptor() in essence, and its obscure nature was causing bugs. Just use the real thing and remove arch_deref_entry_point(). Link: https://lkml.kernel.org/r/163163043630.489837.7924988885652708696.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
The following commit: Commit e792ff80 ("ia64: kprobes: Use generic kretprobe trampoline handler") Passed the wrong trampoline address to __kretprobe_trampoline_handler(): it passes the descriptor address instead of function entry address. Pass the right parameter. Also use correct symbol dereference function to get the function address from 'kretprobe_trampoline' - an IA64 special. Link: https://lkml.kernel.org/r/163163042696.489837.12551102356265354730.stgit@devnote2 Fixes: e792ff80 ("ia64: kprobes: Use generic kretprobe trampoline handler") Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: X86 ML <x86@kernel.org> Cc: Daniel Xu <dxu@dxuuu.xyz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Paul McKenney <paulmck@kernel.org> Cc: stable@vger.kernel.org Signed-off-by:
-
Masami Hiramatsu authored
Use the 'bool' type instead of 'int' for the functions which returns a boolean value, because this makes clear that those functions don't return any error code. Link: https://lkml.kernel.org/r/163163041649.489837.17311187321419747536.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Since get_optimized_kprobe() is only used inside kprobes, it doesn't need to use 'unsigned long' type for 'addr' parameter. Make it use 'kprobe_opcode_t *' for the 'addr' parameter and subsequent call of arch_within_optimized_kprobe() also should use 'kprobe_opcode_t *'. Note that MAX_OPTIMIZED_LENGTH and RELATIVEJUMP_SIZE are defined by byte-size, but the size of 'kprobe_opcode_t' depends on the architecture. Therefore, we must be careful when calculating addresses using those macros. Link: https://lkml.kernel.org/r/163163040680.489837.12133032364499833736.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Add assertions for required locks instead of comment it so that the lockdep can inspect locks automatically. Link: https://lkml.kernel.org/r/163163039572.489837.18011973177537476885.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Use IS_ENABLED(CONFIG_KPROBES) instead of kprobes_built_in(). This inline function is introduced only for avoiding #ifdef. But since now we have IS_ENABLED(), it is no longer needed. Link: https://lkml.kernel.org/r/163163038581.489837.2805250706507372658.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
Fix coding style issues reported by checkpatch.pl and update comments to quote variable names and add "()" to function name. One TODO comment in __disarm_kprobe() is removed because it has been done by following commit. Link: https://lkml.kernel.org/r/163163037468.489837.4282347782492003960.stgit@devnote2Signed-off-by:
-
Masami Hiramatsu authored
This clean up the error/notification messages in kprobes related code. Basically this defines 'pr_fmt()' macros for each files and update the messages which describes - what happened, - what is the kernel going to do or not do, - is the kernel fine, - what can the user do about it. Also, if the message is not needed (e.g. the function returns unique error code, or other error message is already shown.) remove it, and replace the message with WARN_*() macros if suitable. Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2Signed-off-by:
-
Punit Agrawal authored
arch_check_ftrace_location() was introduced as a weak function in commit f7f242ff ("kprobes: introduce weak arch_check_ftrace_location() helper function") to allow architectures to handle kprobes call site on their own. Recently, the only architecture (csky) to implement arch_check_ftrace_location() was migrated to using the common version. As a result, further cleanup the code to drop the weak attribute and rename the function to remove the architecture specific implementation. Link: https://lkml.kernel.org/r/163163035673.489837.2367816318195254104.stgit@devnote2Signed-off-by:
Punit Agrawal <punitagrawal@gmail.com> Acked-by:
-
Punit Agrawal authored
The csky specific arch_check_ftrace_location() shadows a weak implementation of the function in core code that offers the same functionality but with additional error checking. Drop the architecture specific function as a step towards further cleanup in core code. Link: https://lkml.kernel.org/r/163163034617.489837.7789033031868135258.stgit@devnote2Signed-off-by:
Guo Ren <guoren@kernel.org> Acked-by:
-
Punit Agrawal authored
The function prepare_kprobe() is called during kprobe registration and is responsible for ensuring any architecture related preparation for the kprobe is done before returning. One of two versions of prepare_kprobe() is chosen depending on the availability of KPROBE_ON_FTRACE in the kernel configuration. Simplify the code by dropping the version when KPROBE_ON_FTRACE is not selected - instead relying on kprobe_ftrace() to return false when KPROBE_ON_FTRACE is not set. No functional change. Link: https://lkml.kernel.org/r/163163033696.489837.9264661820279300788.stgit@devnote2Signed-off-by:
-
Punit Agrawal authored
The "enabled" file provides a debugfs interface to arm / disarm kprobes in the kernel. In order to parse the buffer containing the values written from userspace, the callback manually parses the user input to convert it to a boolean value. As taking a string value from userspace and converting it to boolean is a common operation, a helper kstrtobool_from_user() is already available in the kernel. Update the callback to use the common helper to parse the write buffer from userspace. Link: https://lkml.kernel.org/r/163163032637.489837.10678039554832855327.stgit@devnote2Signed-off-by:
-
Punit Agrawal authored
debugfs_create_file() takes a pointer argument that can be used during file operation callbacks (accessible via i_private in the inode structure). An obvious requirement is for the pointer to refer to valid memory when used. When creating the debugfs file to dynamically enable / disable kprobes, a pointer to local variable is passed to debugfs_create_file(); which will go out of scope when the init function returns. The reason this hasn't triggered random memory corruption is because the pointer is not accessed during the debugfs file callbacks. Since the enabled state is managed by the kprobes_all_disabled global variable, the local variable is not needed. Fix the incorrect (and unnecessary) usage of local variable during debugfs_file_create() by passing NULL instead. Link: https://lkml.kernel.org/r/163163031686.489837.4476867635937014973.stgit@devnote2 Fixes: bf8f6e5b ("Kprobes: The ON/OFF knob thru debugfs") Signed-off-by:
-
- 26 Sep, 2021 7 commits
-
-
Linus Torvalds authored
-
git://git.samba.org/ksmbdLinus Torvalds authored
Pull ksmbd fixes from Steve French: "Five fixes for the ksmbd kernel server, including three security fixes: - remove follow symlinks support - use LOOKUP_BENEATH to prevent out of share access - SMB3 compounding security fix - fix for returning the default streams correctly, fixing a bug when writing ppt or doc files from some clients - logging more clearly that ksmbd is experimental (at module load time)" * tag '5.15-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd: ksmbd: use LOOKUP_BENEATH to prevent the out of share access ksmbd: remove follow symlinks support ksmbd: check protocol id in ksmbd_verify_smb_message() ksmbd: add default data stream name in FILE_STREAM_INFORMATION ksmbd: log that server is experimental at module load -
git://git.kernel.org/pub/scm/linux/kernel/git/ras/rasLinus Torvalds authored
Pull EDAC fixes from Borislav Petkov: "Fix two EDAC drivers using the wrong value type for the DIMM mode" * tag 'edac_urgent_for_v5.15_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: EDAC/dmc520: Assign the proper type to dimm->edac_mode EDAC/synopsys: Fix wrong value type assignment for edac_mode
-
git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linuxLinus Torvalds authored
Pull thermal fixes from Daniel Lezcano: - Fix thermal shutdown after a suspend/resume due to a wrong TCC value restored on Intel platform (Antoine Tenart) - Fix potential buffer overflow when building the list of policies. The buffer size is not updated after writing to it (Dan Carpenter) - Fix wrong check against IS_ERR instead of NULL (Ansuel Smith) * tag 'thermal-v5.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: thermal/drivers/tsens: Fix wrong check for tzd in irq handlers thermal/core: Potential buffer overflow in thermal_build_list_of_policies() thermal/drivers/int340x: Do not set a wrong tcc offset on resume
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: "A set of fixes for X86: - Prevent sending the wrong signal when protection keys are enabled and the kernel handles a fault in the vsyscall emulation. - Invoke early_reserve_memory() before invoking e820_memory_setup() which is required to make the Xen dom0 e820 hooks work correctly. - Use the correct data type for the SETZ operand in the EMQCMDS instruction wrapper. - Prevent undefined behaviour to the potential unaligned accesss in the instruction decoder library" * tag 'x86-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses x86/asm: Fix SETZ size enqcmds() build failure x86/setup: Call early_reserve_memory() earlier x86/fault: Fix wrong signal when vsyscall fails with pkey -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fix from Thomas Gleixner: "A single fix for the recently introduced regression in posix CPU timers which failed to stop the timer when requested. That caused unexpected signals to be sent to the process/thread causing malfunction" * tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-cpu-timers: Prevent spuriously armed 0-value itimer
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull irq fixes from Thomas Gleixner: "A set of fixes for interrupt chip drivers: - Work around a bad GIC integration on a Renesas platform which can't handle byte-sized MMIO access - Plug a potential memory leak in the GICv4 driver - Fix a regression in the Armada 370-XP IPI code which was caused by issuing EOI instack of ACK. - A couple of small fixes here and there" * tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic: Work around broken Renesas integration irqchip/renesas-rza1: Use semicolons instead of commas irqchip/gic-v3-its: Fix potential VPE leak on error irqchip/goldfish-pic: Select GENERIC_IRQ_CHIP to fix build irqchip/mbigen: Repair non-kernel-doc notation irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent irqchip/armada-370-xp: Fix ack/eoi breakage Documentation: Fix irq-domain.rst build warning
-
- 25 Sep, 2021 1 commit
-
-
Linus Torvalds authored
Merge misc fixes from Andrew Morton: "16 patches. Subsystems affected by this patch series: xtensa, sh, ocfs2, scripts, lib, and mm (memory-failure, kasan, damon, shmem, tools, pagecache, debug, and pagemap)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: fix uninitialized use in overcommit_policy_handler mm/memory_failure: fix the missing pte_unmap() call kasan: always respect CONFIG_KASAN_STACK sh: pgtable-3level: fix cast to pointer from integer of different size mm/debug: sync up latest migrate_reason to migrate_reason_names mm/debug: sync up MR_CONTIG_RANGE and MR_LONGTERM_PIN mm: fs: invalidate bh_lrus for only cold path lib/zlib_inflate/inffast: check config in C to avoid unused function warning tools/vm/page-types: remove dependency on opt_file for idle page tracking scripts/sorttable: riscv: fix undeclared identifier 'EM_RISCV' error ocfs2: drop acl cache for directories too mm/shmem.c: fix judgment error in shmem_is_huge() xtensa: increase size of gcc stack frame check mm/damon: don't use strnlen() with known-bogus source length kasan: fix Kconfig check of CC_HAS_WORKING_NOSANITIZE_ADDRESS mm, hwpoison: add is_free_buddy_page() in HWPoisonHandlable()
-
