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 --- fs/jffs2/compr_lzo.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 fs/jffs2/compr_lzo.c (limited to 'fs/jffs2/compr_lzo.c') diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c new file mode 100644 index 000000000..c553bd650 --- /dev/null +++ b/fs/jffs2/compr_lzo.c @@ -0,0 +1,110 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2007 Nokia Corporation. All rights reserved. + * Copyright © 2004-2010 David Woodhouse + * + * Created by Richard Purdie + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#include +#include +#include +#include +#include +#include "compr.h" + +static void *lzo_mem; +static void *lzo_compress_buf; +static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */ + +static void free_workspace(void) +{ + vfree(lzo_mem); + vfree(lzo_compress_buf); +} + +static int __init alloc_workspace(void) +{ + lzo_mem = vmalloc(LZO1X_MEM_COMPRESS); + lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE)); + + if (!lzo_mem || !lzo_compress_buf) { + free_workspace(); + return -ENOMEM; + } + + return 0; +} + +static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, + uint32_t *sourcelen, uint32_t *dstlen) +{ + size_t compress_size; + int ret; + + mutex_lock(&deflate_mutex); + ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem); + if (ret != LZO_E_OK) + goto fail; + + if (compress_size > *dstlen) + goto fail; + + memcpy(cpage_out, lzo_compress_buf, compress_size); + mutex_unlock(&deflate_mutex); + + *dstlen = compress_size; + return 0; + + fail: + mutex_unlock(&deflate_mutex); + return -1; +} + +static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, + uint32_t srclen, uint32_t destlen) +{ + size_t dl = destlen; + int ret; + + ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl); + + if (ret != LZO_E_OK || dl != destlen) + return -1; + + return 0; +} + +static struct jffs2_compressor jffs2_lzo_comp = { + .priority = JFFS2_LZO_PRIORITY, + .name = "lzo", + .compr = JFFS2_COMPR_LZO, + .compress = &jffs2_lzo_compress, + .decompress = &jffs2_lzo_decompress, + .disabled = 0, +}; + +int __init jffs2_lzo_init(void) +{ + int ret; + + ret = alloc_workspace(); + if (ret < 0) + return ret; + + ret = jffs2_register_compressor(&jffs2_lzo_comp); + if (ret) + free_workspace(); + + return ret; +} + +void jffs2_lzo_exit(void) +{ + jffs2_unregister_compressor(&jffs2_lzo_comp); + free_workspace(); +} -- cgit v1.3.1