linux/lib/bootconfig.c, branch v5.15

memblock: introduce saner 'memblock_free_ptr()' interface

2021-09-14T20:23:22Z

The boot-time allocation interface for memblock is a mess, with 'memblock_alloc()' returning a virtual pointer, but then you are supposed to free it with 'memblock_free()' that takes a _physical_ address. Not only is that all kinds of strange and illogical, but it actually causes bugs, when people then use it like a normal allocation function, and it fails spectacularly on a NULL pointer: https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/ or just random memory corruption if the debug checks don't catch it: https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/ I really don't want to apply patches that treat the symptoms, when the fundamental cause is this horribly confusing interface. I started out looking at just automating a sane replacement sequence, but because of this mix or virtual and physical addresses, and because people have used the "__pa()" macro that can take either a regular kernel pointer, or just the raw "unsigned long" address, it's all quite messy. So this just introduces a new saner interface for freeing a virtual address that was allocated using 'memblock_alloc()', and that was kept as a regular kernel pointer. And then it converts a couple of users that are obvious and easy to test, including the 'xbc_nodes' case in lib/bootconfig.c that caused problems. Reported-by: kernel test robot Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed") Cc: Steven Rostedt Cc: Mike Rapoport Cc: Andrew Morton Cc: Ingo Molnar Cc: Masami Hiramatsu Cc: Vlastimil Babka Signed-off-by: Linus Torvalds

bootconfig: Rename xbc_node_find_child() to xbc_node_find_subkey()

2021-09-09T23:14:33Z

Rename xbc_node_find_child() to xbc_node_find_subkey() for clarifying that function returns a key node (no value node). Since there are xbc_node_for_each_child() (loop on all child nodes) and xbc_node_for_each_subkey() (loop on only subkey nodes), this name distinction is necessary to avoid confusing users. Link: https://lkml.kernel.org/r/163119459826.161018.11200274779483115300.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

bootconfig: Support mixing a value and subkeys under a key

2021-06-10T17:41:26Z

Support mixing a value and subkeys under a key. Since kernel cmdline options will support "aaa.bbb=value1 aaa.bbb.ccc=value2", it is better that the bootconfig supports such configuration too. Note that this does not change syntax itself but just accepts mixed value and subkeys e.g. key = value1 key.subkey = value2 But this is not accepted; key { value1 subkey = value2 } That will make value1 as a subkey. Also, the order of the value node under a key is fixed. If there are a value and subkeys, the value is always the first child node of the key. Thus if user specifies subkeys first, e.g. key.subkey = value1 key = value2 In the program (and /proc/bootconfig), it will be shown as below key = value2 key.subkey = value1 Link: https://lkml.kernel.org/r/162262194685.264090.7738574774030567419.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

bootconfig: Change array value to use child node

2021-06-10T17:38:25Z

It is not possible to put an array value with subkeys under a key node, because both of subkeys and the array elements are using "next" field of the xbc_node. Thus this changes the array values to use "child" field in the array case. The reason why split this change is to test it easily. Link: https://lkml.kernel.org/r/162262193838.264090.16044473274501498656.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"

2020-11-18T20:15:17Z

This reverts commit 6a9dc5fd6170 ("lib: Revert use of fallthrough pseudo-keyword in lib/") Now that we can build arch/powerpc/boot/ free of -Wimplicit-fallthrough, re-enable these fixes for lib/. Signed-off-by: Nick Desaulniers Tested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Reviewed-by: Gustavo A. R. Silva Reviewed-by: Miguel Ojeda Link: https://github.com/ClangBuiltLinux/linux/issues/236 Signed-off-by: Gustavo A. R. Silva

lib/bootconfig: Fix to remove tailing spaces after value

2020-09-22T01:50:09Z

Fix to remove tailing spaces after value. If there is a space after value, the bootconfig failed to remove it because it applies strim() before replacing the delimiter with null. For example, foo = var # comment was parsed as below. foo="var " but user will expect foo="var" This fixes it by applying strim() after removing the delimiter. Link: https://lkml.kernel.org/r/160068149134.1088739.8868306567670058853.stgit@devnote2 Fixes: 76db5a27a827 ("bootconfig: Add Extra Boot Config support") Cc: Ingo Molnar Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

lib/bootconfig: Fix a bug of breaking existing tree nodes

2020-09-22T01:45:52Z

Fix a bug of breaking existing tree nodes by parsing the second and subsequent braces. Since the bootconfig parser uses the node.next field as a flag of current parent node, but this will break the existing tree if the same key node is specified again in the bootconfig. For example, the following bootconfig should be foo.buz and bar. foo bar foo { buz } However, when parsing the brace "{", it breaks foo->bar link by marking open-brace node. So the bootconfig unlinks bar from the bootconfig internal tree. This introduces a stack outside of the tree and record the last open-brace on the stack instead of using node.next field. Link: https://lkml.kernel.org/r/160068148267.1088739.8264704338030168660.stgit@devnote2 Fixes: 76db5a27a827 ("bootconfig: Add Extra Boot Config support") Cc: Ingo Molnar Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

lib: Revert use of fallthrough pseudo-keyword in lib/

2020-08-24T21:17:44Z

The following build error for powerpc64 was reported by Nathan Chancellor: "$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ $ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage ... In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234, from arch/powerpc/boot/decompress.c:38: arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main': arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function) 586 | fallthrough; | ^~~~~~~~~~~ This will end up affecting distribution configurations such as Debian and OpenSUSE according to my testing. I am not sure what the solution is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure that compiler_attributes.h can be safely included." In order to avoid these sort of problems, it seems that the best solution is to use /* fall through */ comments instead of the fallthrough pseudo-keyword macro in lib/, for now. Reported-by: Nathan Chancellor Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword") Signed-off-by: Gustavo A. R. Silva Reviewed-and-tested-by: Nathan Chancellor Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

lib/bootconfig: Add override operator support

2020-08-03T20:22:28Z

Add the value override operator (":=") support to the bootconfig. This value override operator will be useful for the bootloaders which will only update the existing bootconfig according to the bootloader boot options. Without this override operator, the bootloader needs to parse the existing bootconfig and update it. However, with this assignment, it can just append the updated (partial) bootconfig text at the tail of existing one without parsing it. (Of course, it must update the size, checksum and magic, but that will be done easily) Link: https://lkml.kernel.org/r/159482882954.126704.16209517125614438640.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)