From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- lib/zstd/common/compiler.h | 289 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 lib/zstd/common/compiler.h (limited to 'lib/zstd/common/compiler.h') diff --git a/lib/zstd/common/compiler.h b/lib/zstd/common/compiler.h new file mode 100644 index 000000000..dc9bd15e1 --- /dev/null +++ b/lib/zstd/common/compiler.h @@ -0,0 +1,289 @@ +/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +#ifndef ZSTD_COMPILER_H +#define ZSTD_COMPILER_H + +#include + +#include "portability_macros.h" + +/*-******************************************************* +* Compiler specifics +*********************************************************/ +/* force inlining */ + +#if !defined(ZSTD_NO_INLINE) +#if (defined(__GNUC__) && !defined(__STRICT_ANSI__)) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ +# define INLINE_KEYWORD inline +#else +# define INLINE_KEYWORD +#endif + +#define FORCE_INLINE_ATTR __attribute__((always_inline)) + +#else + +#define INLINE_KEYWORD +#define FORCE_INLINE_ATTR + +#endif + +/* + On MSVC qsort requires that functions passed into it use the __cdecl calling conversion(CC). + This explicitly marks such functions as __cdecl so that the code will still compile + if a CC other than __cdecl has been made the default. +*/ +#define WIN_CDECL + +/* UNUSED_ATTR tells the compiler it is okay if the function is unused. */ +#define UNUSED_ATTR __attribute__((unused)) + +/* + * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant + * parameters. They must be inlined for the compiler to eliminate the constant + * branches. + */ +#define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR UNUSED_ATTR +/* + * HINT_INLINE is used to help the compiler generate better code. It is *not* + * used for "templates", so it can be tweaked based on the compilers + * performance. + * + * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the + * always_inline attribute. + * + * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline + * attribute. + */ +#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5 +# define HINT_INLINE static INLINE_KEYWORD +#else +# define HINT_INLINE FORCE_INLINE_TEMPLATE +#endif + +/* "soft" inline : + * The compiler is free to select if it's a good idea to inline or not. + * The main objective is to silence compiler warnings + * when a defined function in included but not used. + * + * Note : this macro is prefixed `MEM_` because it used to be provided by `mem.h` unit. + * Updating the prefix is probably preferable, but requires a fairly large codemod, + * since this name is used everywhere. + */ +#ifndef MEM_STATIC /* already defined in Linux Kernel mem.h */ +#define MEM_STATIC static __inline UNUSED_ATTR +#endif + +/* force no inlining */ +#define FORCE_NOINLINE static __attribute__((__noinline__)) + + +/* target attribute */ +#define TARGET_ATTRIBUTE(target) __attribute__((__target__(target))) + +/* Target attribute for BMI2 dynamic dispatch. + * Enable lzcnt, bmi, and bmi2. + * We test for bmi1 & bmi2. lzcnt is included in bmi1. + */ +#define BMI2_TARGET_ATTRIBUTE TARGET_ATTRIBUTE("lzcnt,bmi,bmi2") + +/* prefetch + * can be disabled, by declaring NO_PREFETCH build macro */ +#if ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) ) +# define PREFETCH_L1(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */) +# define PREFETCH_L2(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */) +#elif defined(__aarch64__) +# define PREFETCH_L1(ptr) do { __asm__ __volatile__("prfm pldl1keep, %0" ::"Q"(*(ptr))); } while (0) +# define PREFETCH_L2(ptr) do { __asm__ __volatile__("prfm pldl2keep, %0" ::"Q"(*(ptr))); } while (0) +#else +# define PREFETCH_L1(ptr) do { (void)(ptr); } while (0) /* disabled */ +# define PREFETCH_L2(ptr) do { (void)(ptr); } while (0) /* disabled */ +#endif /* NO_PREFETCH */ + +#define CACHELINE_SIZE 64 + +#define PREFETCH_AREA(p, s) \ + do { \ + const char* const _ptr = (const char*)(p); \ + size_t const _size = (size_t)(s); \ + size_t _pos; \ + for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \ + PREFETCH_L2(_ptr + _pos); \ + } \ + } while (0) + +/* vectorization + * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax, + * and some compilers, like Intel ICC and MCST LCC, do not support it at all. */ +#if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__) && !defined(__LCC__) +# if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5) +# define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize"))) +# else +# define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")") +# endif +#else +# define DONT_VECTORIZE +#endif + +/* Tell the compiler that a branch is likely or unlikely. + * Only use these macros if it causes the compiler to generate better code. + * If you can remove a LIKELY/UNLIKELY annotation without speed changes in gcc + * and clang, please do. + */ +#define LIKELY(x) (__builtin_expect((x), 1)) +#define UNLIKELY(x) (__builtin_expect((x), 0)) + +#if __has_builtin(__builtin_unreachable) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))) +# define ZSTD_UNREACHABLE do { assert(0), __builtin_unreachable(); } while (0) +#else +# define ZSTD_UNREACHABLE do { assert(0); } while (0) +#endif + +/* disable warnings */ + +/* compile time determination of SIMD support */ + +/* C-language Attributes are added in C23. */ +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute) +# define ZSTD_HAS_C_ATTRIBUTE(x) __has_c_attribute(x) +#else +# define ZSTD_HAS_C_ATTRIBUTE(x) 0 +#endif + +/* Only use C++ attributes in C++. Some compilers report support for C++ + * attributes when compiling with C. + */ +#define ZSTD_HAS_CPP_ATTRIBUTE(x) 0 + +/* Define ZSTD_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute. + * - C23: https://en.cppreference.com/w/c/language/attributes/fallthrough + * - CPP17: https://en.cppreference.com/w/cpp/language/attributes/fallthrough + * - Else: __attribute__((__fallthrough__)) + */ +#define ZSTD_FALLTHROUGH fallthrough + +/*-************************************************************** +* Alignment +*****************************************************************/ + +/* @return 1 if @u is a 2^n value, 0 otherwise + * useful to check a value is valid for alignment restrictions */ +MEM_STATIC int ZSTD_isPower2(size_t u) { + return (u & (u-1)) == 0; +} + +/* this test was initially positioned in mem.h, + * but this file is removed (or replaced) for linux kernel + * so it's now hosted in compiler.h, + * which remains valid for both user & kernel spaces. + */ + +#ifndef ZSTD_ALIGNOF +/* covers gcc, clang & MSVC */ +/* note : this section must come first, before C11, + * due to a limitation in the kernel source generator */ +# define ZSTD_ALIGNOF(T) __alignof(T) + +#endif /* ZSTD_ALIGNOF */ + +#ifndef ZSTD_ALIGNED +/* C90-compatible alignment macro (GCC/Clang). Adjust for other compilers if needed. */ +#define ZSTD_ALIGNED(a) __attribute__((aligned(a))) +#endif /* ZSTD_ALIGNED */ + + +/*-************************************************************** +* Sanitizer +*****************************************************************/ + +/* + * Zstd relies on pointer overflow in its decompressor. + * We add this attribute to functions that rely on pointer overflow. + */ +#ifndef ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +# if __has_attribute(no_sanitize) +# if !defined(__clang__) && defined(__GNUC__) && __GNUC__ < 8 + /* gcc < 8 only has signed-integer-overlow which triggers on pointer overflow */ +# define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR __attribute__((no_sanitize("signed-integer-overflow"))) +# else + /* older versions of clang [3.7, 5.0) will warn that pointer-overflow is ignored. */ +# define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR __attribute__((no_sanitize("pointer-overflow"))) +# endif +# else +# define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +# endif +#endif + +/* + * Helper function to perform a wrapped pointer difference without triggering + * UBSAN. + * + * @returns lhs - rhs with wrapping + */ +MEM_STATIC +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +ptrdiff_t ZSTD_wrappedPtrDiff(unsigned char const* lhs, unsigned char const* rhs) +{ + return lhs - rhs; +} + +/* + * Helper function to perform a wrapped pointer add without triggering UBSAN. + * + * @return ptr + add with wrapping + */ +MEM_STATIC +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +unsigned char const* ZSTD_wrappedPtrAdd(unsigned char const* ptr, ptrdiff_t add) +{ + return ptr + add; +} + +/* + * Helper function to perform a wrapped pointer subtraction without triggering + * UBSAN. + * + * @return ptr - sub with wrapping + */ +MEM_STATIC +ZSTD_ALLOW_POINTER_OVERFLOW_ATTR +unsigned char const* ZSTD_wrappedPtrSub(unsigned char const* ptr, ptrdiff_t sub) +{ + return ptr - sub; +} + +/* + * Helper function to add to a pointer that works around C's undefined behavior + * of adding 0 to NULL. + * + * @returns `ptr + add` except it defines `NULL + 0 == NULL`. + */ +MEM_STATIC +unsigned char* ZSTD_maybeNullPtrAdd(unsigned char* ptr, ptrdiff_t add) +{ + return add > 0 ? ptr + add : ptr; +} + +/* Issue #3240 reports an ASAN failure on an llvm-mingw build. Out of an + * abundance of caution, disable our custom poisoning on mingw. */ +#ifdef __MINGW32__ +#ifndef ZSTD_ASAN_DONT_POISON_WORKSPACE +#define ZSTD_ASAN_DONT_POISON_WORKSPACE 1 +#endif +#ifndef ZSTD_MSAN_DONT_POISON_WORKSPACE +#define ZSTD_MSAN_DONT_POISON_WORKSPACE 1 +#endif +#endif + + + +#endif /* ZSTD_COMPILER_H */ -- cgit v1.3.1