From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/powerpc/boot/stdio.c | 343 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 343 insertions(+) create mode 100644 arch/powerpc/boot/stdio.c (limited to 'arch/powerpc/boot/stdio.c') diff --git a/arch/powerpc/boot/stdio.c b/arch/powerpc/boot/stdio.c new file mode 100644 index 000000000..b12aa2c0b --- /dev/null +++ b/arch/powerpc/boot/stdio.c @@ -0,0 +1,343 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) Paul Mackerras 1997. + */ +#include +#include +#include "string.h" +#include "stdio.h" +#include "ops.h" + +size_t strnlen(const char * s, size_t count) +{ + const char *sc; + + for (sc = s; count-- && *sc != '\0'; ++sc) + /* nothing */; + return sc - s; +} + +char *strrchr(const char *s, int c) +{ + const char *last = NULL; + do { + if (*s == (char)c) + last = s; + } while (*s++); + return (char *)last; +} + +#ifdef __powerpc64__ + +# define do_div(n, base) ({ \ + unsigned int __base = (base); \ + unsigned int __rem; \ + __rem = ((unsigned long long)(n)) % __base; \ + (n) = ((unsigned long long)(n)) / __base; \ + __rem; \ +}) + +#else + +extern unsigned int __div64_32(unsigned long long *dividend, + unsigned int divisor); + +/* The unnecessary pointer compare is there + * to check for type safety (n must be 64bit) + */ +# define do_div(n,base) ({ \ + unsigned int __base = (base); \ + unsigned int __rem; \ + (void)(((typeof((n)) *)0) == ((unsigned long long *)0)); \ + if (((n) >> 32) == 0) { \ + __rem = (unsigned int)(n) % __base; \ + (n) = (unsigned int)(n) / __base; \ + } else \ + __rem = __div64_32(&(n), __base); \ + __rem; \ + }) + +#endif /* __powerpc64__ */ + +static int skip_atoi(const char **s) +{ + int i, c; + + for (i = 0; '0' <= (c = **s) && c <= '9'; ++*s) + i = i*10 + c - '0'; + return i; +} + +#define ZEROPAD 1 /* pad with zero */ +#define SIGN 2 /* unsigned/signed long */ +#define PLUS 4 /* show plus */ +#define SPACE 8 /* space if plus */ +#define LEFT 16 /* left justified */ +#define SPECIAL 32 /* 0x */ +#define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ + +static char * number(char * str, unsigned long long num, int base, int size, int precision, int type) +{ + char c,sign,tmp[66]; + const char *digits="0123456789abcdefghijklmnopqrstuvwxyz"; + int i; + + if (type & LARGE) + digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; + if (type & LEFT) + type &= ~ZEROPAD; + if (base < 2 || base > 36) + return 0; + c = (type & ZEROPAD) ? '0' : ' '; + sign = 0; + if (type & SIGN) { + if ((signed long long)num < 0) { + sign = '-'; + num = - (signed long long)num; + size--; + } else if (type & PLUS) { + sign = '+'; + size--; + } else if (type & SPACE) { + sign = ' '; + size--; + } + } + if (type & SPECIAL) { + if (base == 16) + size -= 2; + else if (base == 8) + size--; + } + i = 0; + if (num == 0) + tmp[i++]='0'; + else while (num != 0) { + tmp[i++] = digits[do_div(num, base)]; + } + if (i > precision) + precision = i; + size -= precision; + if (!(type&(ZEROPAD+LEFT))) + while(size-->0) + *str++ = ' '; + if (sign) + *str++ = sign; + if (type & SPECIAL) { + if (base==8) + *str++ = '0'; + else if (base==16) { + *str++ = '0'; + *str++ = digits[33]; + } + } + if (!(type & LEFT)) + while (size-- > 0) + *str++ = c; + while (i < precision--) + *str++ = '0'; + while (i-- > 0) + *str++ = tmp[i]; + while (size-- > 0) + *str++ = ' '; + return str; +} + +int vsprintf(char *buf, const char *fmt, va_list args) +{ + int len; + unsigned long long num; + int i, base; + char * str; + const char *s; + + int flags; /* flags to number() */ + + int field_width; /* width of output field */ + int precision; /* min. # of digits for integers; max + number of chars for from string */ + int qualifier; /* 'h', 'l', or 'L' for integer fields */ + /* 'z' support added 23/7/1999 S.H. */ + /* 'z' changed to 'Z' --davidm 1/25/99 */ + + + for (str=buf ; *fmt ; ++fmt) { + if (*fmt != '%') { + *str++ = *fmt; + continue; + } + + /* process flags */ + flags = 0; + repeat: + ++fmt; /* this also skips first '%' */ + switch (*fmt) { + case '-': flags |= LEFT; goto repeat; + case '+': flags |= PLUS; goto repeat; + case ' ': flags |= SPACE; goto repeat; + case '#': flags |= SPECIAL; goto repeat; + case '0': flags |= ZEROPAD; goto repeat; + } + + /* get field width */ + field_width = -1; + if ('0' <= *fmt && *fmt <= '9') + field_width = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + field_width = va_arg(args, int); + if (field_width < 0) { + field_width = -field_width; + flags |= LEFT; + } + } + + /* get the precision */ + precision = -1; + if (*fmt == '.') { + ++fmt; + if ('0' <= *fmt && *fmt <= '9') + precision = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + precision = va_arg(args, int); + } + if (precision < 0) + precision = 0; + } + + /* get the conversion qualifier */ + qualifier = -1; + if (*fmt == 'l' && *(fmt + 1) == 'l') { + qualifier = 'q'; + fmt += 2; + } else if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' + || *fmt == 'Z') { + qualifier = *fmt; + ++fmt; + } + + /* default base */ + base = 10; + + switch (*fmt) { + case 'c': + if (!(flags & LEFT)) + while (--field_width > 0) + *str++ = ' '; + *str++ = (unsigned char) va_arg(args, int); + while (--field_width > 0) + *str++ = ' '; + continue; + + case 's': + s = va_arg(args, char *); + if (!s) + s = ""; + + len = strnlen(s, precision); + + if (!(flags & LEFT)) + while (len < field_width--) + *str++ = ' '; + for (i = 0; i < len; ++i) + *str++ = *s++; + while (len < field_width--) + *str++ = ' '; + continue; + + case 'p': + if (field_width == -1) { + field_width = 2*sizeof(void *); + flags |= ZEROPAD; + } + str = number(str, + (unsigned long) va_arg(args, void *), 16, + field_width, precision, flags); + continue; + + + case 'n': + if (qualifier == 'l') { + long * ip = va_arg(args, long *); + *ip = (str - buf); + } else if (qualifier == 'Z') { + size_t * ip = va_arg(args, size_t *); + *ip = (str - buf); + } else { + int * ip = va_arg(args, int *); + *ip = (str - buf); + } + continue; + + case '%': + *str++ = '%'; + continue; + + /* integer number formats - set up the flags and "break" */ + case 'o': + base = 8; + break; + + case 'X': + flags |= LARGE; + case 'x': + base = 16; + break; + + case 'd': + case 'i': + flags |= SIGN; + case 'u': + break; + + default: + *str++ = '%'; + if (*fmt) + *str++ = *fmt; + else + --fmt; + continue; + } + if (qualifier == 'l') { + num = va_arg(args, unsigned long); + if (flags & SIGN) + num = (signed long) num; + } else if (qualifier == 'q') { + num = va_arg(args, unsigned long long); + if (flags & SIGN) + num = (signed long long) num; + } else if (qualifier == 'Z') { + num = va_arg(args, size_t); + } else if (qualifier == 'h') { + num = (unsigned short) va_arg(args, int); + if (flags & SIGN) + num = (signed short) num; + } else { + num = va_arg(args, unsigned int); + if (flags & SIGN) + num = (signed int) num; + } + str = number(str, num, base, field_width, precision, flags); + } + *str = '\0'; + return str-buf; +} + +static char sprint_buf[1024]; + +int +printf(const char *fmt, ...) +{ + va_list args; + int n; + + va_start(args, fmt); + n = vsprintf(sprint_buf, fmt, args); + va_end(args); + if (console_ops.write) + console_ops.write(sprint_buf, n); + return n; +} -- cgit v1.3.1