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/alpha/boot/misc.c | 172 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 arch/alpha/boot/misc.c (limited to 'arch/alpha/boot/misc.c') diff --git a/arch/alpha/boot/misc.c b/arch/alpha/boot/misc.c new file mode 100644 index 000000000..1ab91852d --- /dev/null +++ b/arch/alpha/boot/misc.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * misc.c + * + * This is a collection of several routines from gzip-1.0.3 + * adapted for Linux. + * + * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 + * + * Modified for ARM Linux by Russell King + * + * Nicolas Pitre 1999/04/14 : + * For this code to run directly from Flash, all constant variables must + * be marked with 'const' and all other variables initialized at run-time + * only. This way all non constant variables will end up in the bss segment, + * which should point to addresses in RAM and cleared to 0 on start. + * This allows for a much quicker boot time. + * + * Modified for Alpha, from the ARM version, by Jay Estabrook 2003. + */ + +#include +#include + +#include + +#define memzero(s,n) memset ((s),0,(n)) +#define puts srm_printk +extern long srm_printk(const char *, ...) + __attribute__ ((format (printf, 1, 2))); + +/* + * gzip declarations + */ +#define OF(args) args +#define STATIC static + +typedef unsigned char uch; +typedef unsigned short ush; +typedef unsigned long ulg; + +#define WSIZE 0x8000 /* Window size must be at least 32k, */ + /* and a power of two */ + +static uch *inbuf; /* input buffer */ +static uch *window; /* Sliding window buffer */ + +static unsigned insize; /* valid bytes in inbuf */ +static unsigned inptr; /* index of next byte to be processed in inbuf */ +static unsigned outcnt; /* bytes in output buffer */ + +/* gzip flag byte */ +#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ +#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ +#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ +#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ +#define COMMENT 0x10 /* bit 4 set: file comment present */ +#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ +#define RESERVED 0xC0 /* bit 6,7: reserved */ + +#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf()) + +/* Diagnostic functions */ +#ifdef DEBUG +# define Assert(cond,msg) {if(!(cond)) error(msg);} +# define Trace(x) fprintf x +# define Tracev(x) {if (verbose) fprintf x ;} +# define Tracevv(x) {if (verbose>1) fprintf x ;} +# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} +# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} +#else +# define Assert(cond,msg) +# define Trace(x) +# define Tracev(x) +# define Tracevv(x) +# define Tracec(c,x) +# define Tracecv(c,x) +#endif + +static int fill_inbuf(void); +static void flush_window(void); +static void error(char *m); + +static char *input_data; +static int input_data_size; + +static uch *output_data; +static ulg output_ptr; +static ulg bytes_out; + +static void error(char *m); + +extern int end; +static ulg free_mem_ptr; +static ulg free_mem_end_ptr; + +#define HEAP_SIZE 0x3000 + +#include "../../../lib/inflate.c" + +/* =========================================================================== + * Fill the input buffer. This is called only when the buffer is empty + * and at least one byte is really needed. + */ +int fill_inbuf(void) +{ + if (insize != 0) + error("ran out of input data"); + + inbuf = input_data; + insize = input_data_size; + + inptr = 1; + return inbuf[0]; +} + +/* =========================================================================== + * Write the output window window[0..outcnt-1] and update crc and bytes_out. + * (Used for the decompressed data only.) + */ +void flush_window(void) +{ + ulg c = crc; + unsigned n; + uch *in, *out, ch; + + in = window; + out = &output_data[output_ptr]; + for (n = 0; n < outcnt; n++) { + ch = *out++ = *in++; + c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); + } + crc = c; + bytes_out += (ulg)outcnt; + output_ptr += (ulg)outcnt; + outcnt = 0; +/* puts("."); */ +} + +static void error(char *x) +{ + puts("\n\n"); + puts(x); + puts("\n\n -- System halted"); + + while(1); /* Halt */ +} + +unsigned int +decompress_kernel(void *output_start, + void *input_start, + size_t ksize, + size_t kzsize) +{ + output_data = (uch *)output_start; + input_data = (uch *)input_start; + input_data_size = kzsize; /* use compressed size */ + + /* FIXME FIXME FIXME */ + free_mem_ptr = (ulg)output_start + ksize; + free_mem_end_ptr = (ulg)output_start + ksize + 0x200000; + /* FIXME FIXME FIXME */ + + /* put in temp area to reduce initial footprint */ + window = malloc(WSIZE); + + makecrc(); +/* puts("Uncompressing Linux..."); */ + gunzip(); +/* puts(" done, booting the kernel.\n"); */ + return output_ptr; +} -- cgit v1.3.1