Re: [PATCH 1/2] recursive_action: add ACTION_SORT flag

["Baeuerle, Florian" <Florian.Baeuerle@allegion.com>]

Am Dienstag, den 18.12.2018, 13:22 +0000 schrieb Baeuerle, Florian:
> Add a flag to sort directory entries before recursing into them.
> 
> Since this part of lib/ is used inside barebox as well as in
> scripts/bareboxenv.c, we cannot easily use stringlists from lib/, which
> would have made the code a bit nicer.
> 
> Further, add poison.h from kernel 4.5-rc1, which was the base for
> importing linux headers under scripts/ in a883d9a. This is required for
> actually using kernel linked lists within scripts/ tools.
> 
> Signed-off-by: Florian Bäuerle <florian.baeuerle@allegion.com>
> ---
>  include/libbb.h                   |  1 +
>  lib/list_sort.c                   |  3 +-
>  lib/recursive_action.c            | 61 +++++++++++++++++---
>  scripts/bareboxenv.c              |  6 ++
>  scripts/include/linux/list_sort.h |  1 +
>  scripts/include/linux/poison.h    | 93 ++++++++++++++++++++++++++++++-
>  6 files changed, 155 insertions(+), 10 deletions(-)
>  create mode 100644 scripts/include/linux/list_sort.h
> 
> diff --git a/include/libbb.h b/include/libbb.h
> index a362bd32d..1f6afaa27 100644
> --- a/include/libbb.h
> +++ b/include/libbb.h
> @@ -17,6 +17,7 @@ enum {
>  	ACTION_FOLLOWLINKS    = (1 << 1),
>  	ACTION_DEPTHFIRST  = (1 << 2),
>  	/*ACTION_REVERSE   = (1 << 3), - unused */
> +	ACTION_SORT        = (1 << 4),
>  };
>  
>  int recursive_action(const char *fileName, unsigned flags,
> diff --git a/lib/list_sort.c b/lib/list_sort.c
> index b7e74f260..84c6f6465 100644
> --- a/lib/list_sort.c
> +++ b/lib/list_sort.c
> @@ -1,7 +1,6 @@
>  #ifndef __BAREBOX__
>  #include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/slab.h>
> +#define EXPORT_SYMBOL(x)
>  #else
>  #include <common.h>
>  #include <malloc.h>
> diff --git a/lib/recursive_action.c b/lib/recursive_action.c
> index 345d3db0c..0d7ddbd8e 100644
> --- a/lib/recursive_action.c
> +++ b/lib/recursive_action.c
> @@ -16,6 +16,14 @@
>  
>  #endif
>  
> +#include <linux/list.h>
> +#include <linux/list_sort.h>
> +
> +struct dirlist {
> +	char *dirname;
> +	struct list_head list;
> +};
> +
>  /*
>   * Walk down all the directories under the specified
>   * location, and do something (something specified
> @@ -33,6 +41,19 @@ static int true_action(const char *fileName, struct stat
> *statbuf,
>  	return 1;
>  }
>  
> +static int cmp_dirlist(void *priv, struct list_head *a, struct list_head *b)
> +{
> +	struct dirlist *ra, *rb;
> +
> +	if (a == b)
> +		return 0;
> +
> +	ra = list_entry(a, struct dirlist, list);
> +	rb = list_entry(b, struct dirlist, list);
> +
> +	return strcmp(ra->dirname, rb->dirname);
> +}
> +
>  /* fileAction return value of 0 on any file in directory will make
>   * recursive_action() return 0, but it doesn't stop directory traversal
>   * (fileAction/dirAction will be called on each file).
> @@ -55,9 +76,12 @@ int recursive_action(const char *fileName,
>  {
>  	struct stat statbuf;
>  	unsigned follow;
> +	unsigned sort;
>  	int status;
>  	DIR *dir;
>  	struct dirent *next;
> +	struct dirlist *entry, *entry_tmp;
> +	LIST_HEAD(dirs);
>  
>  	if (!fileAction) fileAction = true_action;
>  	if (!dirAction) dirAction = true_action;
> @@ -106,20 +130,43 @@ int recursive_action(const char *fileName,
>  		/* To trigger: "find -exec rm -rf {} \;" */
>  		goto done_nak_warn;
>  	}
> +	sort = flags & ACTION_SORT;
>  	status = 1;
>  	while ((next = readdir(dir)) != NULL) {
> -		char *nextFile;
> -
> -		nextFile = concat_subpath_file(fileName, next->d_name);
> +		char *nextFile = concat_subpath_file(fileName, next->d_name);
>  		if (nextFile == NULL)
>  			continue;
> -		/* now descend into it, forcing recursion. */
> -		if (!recursive_action(nextFile, flags | ACTION_RECURSE,
> -				fileAction, dirAction, userData, depth+1)) {
> -			status = 0;
> +
> +		if (sort) {
> +			struct dirlist *e = malloc(sizeof(*e));
> +			e->dirname = strdup(next->d_name);

I think this should handle NULLs.

> +			list_add(&e->list, &dirs);
> +		} else {
> +			/* descend into it, forcing recursion. */
> +			if (!recursive_action(nextFile, flags | ACTION_RECURSE,
> +						fileAction, dirAction, userData,
> depth+1)) {
> +				status = 0;
> +			}
>  		}
> +
>  		free(nextFile);
>  	}
> +
> +	if (sort) {
> +		list_sort(NULL, &dirs, &cmp_dirlist);
> +
> +		list_for_each_entry_safe(entry, entry_tmp, &dirs, list)
> +		{
> +			/* descend into it, forcing recursion. */
> +			if (!recursive_action(entry->dirname, flags |
> ACTION_RECURSE,
> +						fileAction, dirAction, userData,
> depth+1)) {
> +				status = 0;
> +			}
> +
> +			list_del(&entry->list);
> +			free(entry->dirname);
> +		}
> +	}
>  	closedir(dir);
>  	if ((flags & ACTION_DEPTHFIRST) &&
>  		!dirAction(fileName, &statbuf, userData, depth)) {
> diff --git a/scripts/bareboxenv.c b/scripts/bareboxenv.c
> index 249e65b25..de57c2fce 100644
> --- a/scripts/bareboxenv.c
> +++ b/scripts/bareboxenv.c
> @@ -34,6 +34,7 @@
>  #include "compiler.h"
>  
>  #define debug(...)
> +#define printk_once(...)
>  
>  /* Find out if the last character of a string matches the one given.
>   * Don't underrun the buffer if the string length is 0.
> @@ -54,6 +55,7 @@ enum {
>  	ACTION_FOLLOWLINKS = (1 << 1),
>  	ACTION_DEPTHFIRST  = (1 << 2),
>  	/*ACTION_REVERSE   = (1 << 3), - unused */
> +	ACTION_SORT        = (1 << 4),
>  };
>  
>  int recursive_action(const char *fileName, unsigned flags,
> @@ -95,6 +97,10 @@ static char *concat_subpath_file(const char *path, const
> char *f)
>  	return concat_path_file(path, f);
>  }
>  
> +#include <linux/list.h>
> +#include <linux/list_sort.h>
> +#include <linux/compiler.h>
> +#include "../lib/list_sort.c"
>  #include "../lib/recursive_action.c"
>  #include "../include/envfs.h"
>  #include "../crypto/crc32.c"
> diff --git a/scripts/include/linux/list_sort.h
> b/scripts/include/linux/list_sort.h
> new file mode 100644
> index 000000000..be889c9ae
> --- /dev/null
> +++ b/scripts/include/linux/list_sort.h
> @@ -0,0 +1 @@
> +#include <../../include/linux/list_sort.h>
> diff --git a/scripts/include/linux/poison.h b/scripts/include/linux/poison.h
> index 0c27bdf14..15927ebc2 100644
> --- a/scripts/include/linux/poison.h
> +++ b/scripts/include/linux/poison.h
> @@ -1 +1,92 @@
> -#include "../../../include/linux/poison.h"
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_POISON_H
> +#define _LINUX_POISON_H
> +
> +/********** include/linux/list.h **********/
> +
> +/*
> + * Architectures might want to move the poison pointer offset
> + * into some well-recognized area such as 0xdead000000000000,
> + * that is also not mappable by user-space exploits:
> + */
> +#ifdef CONFIG_ILLEGAL_POINTER_VALUE
> +# define POISON_POINTER_DELTA _AC(CONFIG_ILLEGAL_POINTER_VALUE, UL)
> +#else
> +# define POISON_POINTER_DELTA 0
> +#endif
> +
> +/*
> + * These are non-NULL pointers that will result in page faults
> + * under normal circumstances, used to verify that nobody uses
> + * non-initialized list entries.
> + */
> +#define LIST_POISON1  ((void *) 0x100 + POISON_POINTER_DELTA)
> +#define LIST_POISON2  ((void *) 0x200 + POISON_POINTER_DELTA)
> +
> +/********** include/linux/timer.h **********/
> +/*
> + * Magic number "tsta" to indicate a static timer initializer
> + * for the object debugging code.
> + */
> +#define TIMER_ENTRY_STATIC	((void *) 0x300 + POISON_POINTER_DELTA)
> +
> +/********** mm/debug-pagealloc.c **********/
> +#ifdef CONFIG_PAGE_POISONING_ZERO
> +#define PAGE_POISON 0x00
> +#else
> +#define PAGE_POISON 0xaa
> +#endif
> +
> +/********** mm/page_alloc.c ************/
> +
> +#define TAIL_MAPPING	((void *) 0x400 + POISON_POINTER_DELTA)
> +
> +/********** mm/slab.c **********/
> +/*
> + * Magic nums for obj red zoning.
> + * Placed in the first word before and the first word after an obj.
> + */
> +#define	RED_INACTIVE	0x09F911029D74E35BULL	/* when obj is
> inactive */
> +#define	RED_ACTIVE	0xD84156C5635688C0ULL	/* when obj is active
> */
> +
> +#define SLUB_RED_INACTIVE	0xbb
> +#define SLUB_RED_ACTIVE		0xcc
> +
> +/* ...and for poisoning */
> +#define	POISON_INUSE	0x5a	/* for use-uninitialised poisoning */
> +#define POISON_FREE	0x6b	/* for use-after-free poisoning */
> +#define	POISON_END	0xa5	/* end-byte of poisoning */
> +
> +/********** arch/$ARCH/mm/init.c **********/
> +#define POISON_FREE_INITMEM	0xcc
> +
> +/********** arch/ia64/hp/common/sba_iommu.c **********/
> +/*
> + * arch/ia64/hp/common/sba_iommu.c uses a 16-byte poison string with a
> + * value of "SBAIOMMU POISON\0" for spill-over poisoning.
> + */
> +
> +/********** fs/jbd/journal.c **********/
> +#define JBD_POISON_FREE		0x5b
> +#define JBD2_POISON_FREE	0x5c
> +
> +/********** drivers/base/dmapool.c **********/
> +#define	POOL_POISON_FREED	0xa7	/* !inuse */
> +#define	POOL_POISON_ALLOCATED	0xa9	/* !initted */
> +
> +/********** drivers/atm/ **********/
> +#define ATM_POISON_FREE		0x12
> +#define ATM_POISON		0xdeadbeef
> +
> +/********** kernel/mutexes **********/
> +#define MUTEX_DEBUG_INIT	0x11
> +#define MUTEX_DEBUG_FREE	0x22
> +#define MUTEX_POISON_WW_CTX	((void *) 0x500 + POISON_POINTER_DELTA)
> +
> +/********** lib/flex_array.c **********/
> +#define FLEX_ARRAY_FREE	0x6c	/* for use-after-free poisoning */
> +
> +/********** security/ **********/
> +#define KEY_DESTROY		0xbd
> +
> +#endif
> -- 
> 2.19.2
> 
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