From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- lib/glob.c | 155 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 lib/glob.c (limited to 'lib/glob.c') diff --git a/lib/glob.c b/lib/glob.c new file mode 100644 index 000000000..c80d9dd73 --- /dev/null +++ b/lib/glob.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +#include +#include +#include + +/* + * The only reason this code can be compiled as a module is because the + * ATA code that depends on it can be as well. In practice, they're + * both usually compiled in and the module overhead goes away. + */ +MODULE_DESCRIPTION("glob(7) matching"); +MODULE_LICENSE("Dual MIT/GPL"); + +static bool __pure glob_match_str(char const *pat, char const *str, + char const *str_end); + +/** + * glob_match - Shell-style pattern matching, like !fnmatch(pat, str, 0) + * @pat: Shell-style pattern to match, e.g. "*.[ch]". + * @str: String to match. The pattern must match the entire string. + * + * Perform shell-style glob matching, returning true (1) if the match + * succeeds, or false (0) if it fails. Equivalent to !fnmatch(@pat, @str, 0). + * + * Pattern metacharacters are ?, *, [ and \. + * (And, inside character classes, !, - and ].) + * + * This is a small and simple implementation intended for device denylists + * where a string is matched against a number of patterns. Thus, it + * does not preprocess the patterns. It is non-recursive, and run-time + * is at most quadratic: strlen(@str)*strlen(@pat). + * + * An example of the worst case is glob_match("*aaaaa", "aaaaaaaaaa"); + * it takes 6 passes over the pattern before matching the string. + * + * Like !fnmatch(@pat, @str, 0) and unlike the shell, this does NOT + * treat / or leading . specially; it isn't actually used for pathnames. + * + * Note that according to glob(7) (and unlike bash), character classes + * are complemented by a leading !; this does not support the regex-style + * [^a-z] syntax. + * + * An opening bracket without a matching close is matched literally. + */ +bool __pure glob_match(char const *pat, char const *str) +{ + return glob_match_str(pat, str, NULL); +} +EXPORT_SYMBOL(glob_match); + +/** + * glob_match_len - glob match against a length-bounded string + * @pat: Shell-style pattern to match. + * @str: String to match. Need not be NUL-terminated. + * @len: Number of bytes of @str that may be read. + * + * Like glob_match(), but @str is only read up to @len bytes, so it can be + * used on buffers that are not NUL-terminated (e.g. trace event fields). + * A NUL byte within @len still terminates the string. + */ +bool __pure glob_match_len(char const *pat, char const *str, size_t len) +{ + return glob_match_str(pat, str, str + len); +} +EXPORT_SYMBOL(glob_match_len); + +static bool __pure glob_match_str(char const *pat, char const *str, + char const *str_end) +{ + /* + * Backtrack to previous * on mismatch and retry starting one + * character later in the string. Because * matches all characters + * (no exception for /), it can be easily proved that there's + * never a need to backtrack multiple levels. + */ + char const *back_pat = NULL, *back_str = NULL; + + /* + * Loop over each token (character or class) in pat, matching + * it against the remaining unmatched tail of str. Return false + * on mismatch, or true after matching the trailing nul bytes. + */ + for (;;) { + unsigned char c = (str_end && str >= str_end) ? '\0' : *str; + unsigned char d = *pat++; + + str++; + + switch (d) { + case '?': /* Wildcard: anything but nul */ + if (c == '\0') + return false; + break; + case '*': /* Any-length wildcard */ + if (*pat == '\0') /* Optimize trailing * case */ + return true; + back_pat = pat; + back_str = --str; /* Allow zero-length match */ + break; + case '[': { /* Character class */ + if (c == '\0') /* No possible match */ + return false; + bool match = false, inverted = (*pat == '!'); + char const *class = inverted ? pat + 1 : pat; + unsigned char a = *class++; + + /* + * Iterate over each span in the character class. + * A span is either a single character a, or a + * range a-b. The first span may begin with ']'. + */ + do { + unsigned char b = a; + + if (a == '\0') /* Malformed */ + goto literal; + + if (class[0] == '-' && class[1] != ']') { + b = class[1]; + + if (b == '\0') + goto literal; + + class += 2; + /* Any special action if a > b? */ + } + if (a <= c && c <= b) + match = true; + } while ((a = *class++) != ']'); + + if (match == inverted) + goto backtrack; + pat = class; + } + break; + case '\\': + d = *pat++; + fallthrough; + default: /* Literal character */ +literal: + if (c == d) { + if (d == '\0') + return true; + break; + } +backtrack: + if (c == '\0' || !back_pat) + return false; /* No point continuing */ + /* Try again from last *, one character later in str. */ + pat = back_pat; + str = ++back_str; + break; + } + } +} -- cgit v1.3.1