From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- fs/cramfs/README | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 fs/cramfs/README (limited to 'fs/cramfs/README') diff --git a/fs/cramfs/README b/fs/cramfs/README new file mode 100644 index 000000000..c0052a11a --- /dev/null +++ b/fs/cramfs/README @@ -0,0 +1,107 @@ +Notes on Filesystem Layout +-------------------------- + +These notes describe what mkcramfs generates. Kernel requirements are +a bit looser, e.g. it doesn't care if the items are +swapped around (though it does care that directory entries (inodes) in +a given directory are contiguous, as this is used by readdir). + +All data is currently in host-endian format; neither mkcramfs nor the +kernel ever do swabbing. (See section `Block Size' below.) + +: + + + + +: struct cramfs_super (see cramfs_fs.h). + +: + For each file: + struct cramfs_inode (see cramfs_fs.h). + Filename. Not generally null-terminated, but it is + null-padded to a multiple of 4 bytes. + +The order of inode traversal is described as "width-first" (not to be +confused with breadth-first); i.e. like depth-first but listing all of +a directory's entries before recursing down its subdirectories: the +same order as `ls -AUR' (but without the /^\..*:$/ directory header +lines); put another way, the same order as `find -type d -exec +ls -AU1 {} \;'. + +Beginning in 2.4.7, directory entries are sorted. This optimization +allows cramfs_lookup to return more quickly when a filename does not +exist, speeds up user-space directory sorts, etc. + +: + One for each file that's either a symlink or a + regular file of non-zero st_size. + +: + nblocks * + (where nblocks = (st_size - 1) / blksize + 1) + nblocks * + padding to multiple of 4 bytes + +The i'th for a file stores the byte offset of the +*end* of the i'th (i.e. one past the last byte, which is the +same as the start of the (i+1)'th if there is one). The first + immediately follows the last for the file. +s are each 32 bits long. + +When the CRAMFS_FLAG_EXT_BLOCK_POINTERS capability bit is set, each +'s top bits may contain special flags as follows: + +CRAMFS_BLK_FLAG_UNCOMPRESSED (bit 31): + The block data is not compressed and should be copied verbatim. + +CRAMFS_BLK_FLAG_DIRECT_PTR (bit 30): + The stores the actual block start offset and not + its end, shifted right by 2 bits. The block must therefore be + aligned to a 4-byte boundary. The block size is either blksize + if CRAMFS_BLK_FLAG_UNCOMPRESSED is also specified, otherwise + the compressed data length is included in the first 2 bytes of + the block data. This is used to allow discontiguous data layout + and specific data block alignments e.g. for XIP applications. + + +The order of 's is a depth-first descent of the directory +tree, i.e. the same order as `find -size +0 \( -type f -o -type l \) +-print'. + + +: The i'th is the output of zlib's compress function +applied to the i'th blksize-sized chunk of the input data if the +corresponding CRAMFS_BLK_FLAG_UNCOMPRESSED bit is not set, +otherwise it is the input data directly. +(For the last of the file, the input may of course be smaller.) +Each may be a different size. (See above.) + +s are merely byte-aligned, not generally u32-aligned. + +When CRAMFS_BLK_FLAG_DIRECT_PTR is specified then the corresponding + may be located anywhere and not necessarily contiguous with +the previous/next blocks. In that case it is minimally u32-aligned. +If CRAMFS_BLK_FLAG_UNCOMPRESSED is also specified then the size is always +blksize except for the last block which is limited by the file length. +If CRAMFS_BLK_FLAG_DIRECT_PTR is set and CRAMFS_BLK_FLAG_UNCOMPRESSED +is not set then the first 2 bytes of the block contains the size of the +remaining block data as this cannot be determined from the placement of +logically adjacent blocks. + + +Holes +----- + +This kernel supports cramfs holes (i.e. [efficient representation of] +blocks in uncompressed data consisting entirely of NUL bytes), but by +default mkcramfs doesn't test for & create holes, since cramfs in +kernels up to at least 2.3.39 didn't support holes. Run mkcramfs +with -z if you want it to create files that can have holes in them. + + +Tools +----- + +The cramfs user-space tools, including mkcramfs and cramfsck, are +located at . -- cgit v1.3.1