From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: barebox@lists.infradead.org
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Subject: [PATCH v2 17/19] commands: md: Do not use memmap()
Date: Mon, 28 Jan 2019 22:55:47 -0800 [thread overview]
Message-ID: <20190129065549.29161-18-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20190129065549.29161-1-andrew.smirnov@gmail.com>
Codepaths using memmap() in md.c don't do any boundary checks, so it
can be easily made to read past the underlying file's
boundary. For example on i.MX8MQ based board with 4GiB or RAM we get:
md -b -s /dev/ram0 0xfffffff0
fffffff0: 00 00 00 00 00 00 08 0c 00 02 20 00 20 00 05 20 .......... . ..
100000000: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000010: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000020: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000030: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000040: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000050: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000060: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000070: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000080: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
100000090: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
1000000a0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
1000000b0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
1000000c0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
1000000d0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
1000000e0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
Drop the memmap() realted codepath, so we can realy on boundary
checking done by file I/O layer.
Note that this change has a cosmetic side effect, before:
md -b 0x7ffffffffffffffff000
7ffffffffffff000: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff010: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff020: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff030: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff040: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff050: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff060: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff070: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff080: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff090: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0a0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0b0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0c0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0d0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0e0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
7ffffffffffff0f0: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx ................
after:
md -b 0x7ffffffffffffffff000
7ffffffffffff000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff040: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff090: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
7ffffffffffff0f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
commands/md.c | 8 --------
drivers/misc/mem.c | 2 +-
2 files changed, 1 insertion(+), 9 deletions(-)
diff --git a/commands/md.c b/commands/md.c
index 2389c12d1..507823c67 100644
--- a/commands/md.c
+++ b/commands/md.c
@@ -43,7 +43,6 @@ static int do_mem_md(int argc, char *argv[])
char *filename = "/dev/mem";
int mode = O_RWSIZE_4;
int swab = 0;
- void *map;
void *buf = NULL;
if (argc < 2)
@@ -66,13 +65,6 @@ static int do_mem_md(int argc, char *argv[])
if (fd < 0)
return 1;
- map = memmap(fd, PROT_READ);
- if (map != MAP_FAILED) {
- ret = memory_display(map + start, start, size,
- mode >> O_RWSIZE_SHIFT, swab);
- goto out;
- }
-
buf = xmalloc(RW_BUF_SIZE);
do {
diff --git a/drivers/misc/mem.c b/drivers/misc/mem.c
index 60981a3e9..2f3316307 100644
--- a/drivers/misc/mem.c
+++ b/drivers/misc/mem.c
@@ -8,7 +8,7 @@
#include <init.h>
static struct cdev_operations memops = {
- .read = mem_read,
+ .read = mem_read_nofail,
.write = mem_write,
.memmap = generic_memmap_rw,
};
--
2.20.1
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next prev parent reply other threads:[~2019-01-29 6:56 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 6:55 [PATCH v2 00/19] 32-bit lseek and /dev/mem fixes/improvements Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 01/19] commands: Move mem_parse_options() to lib/misc.c Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 02/19] commands: Get rid of mem_rw_buf Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 03/19] commands: Move /dev/mem driver to drivers/misc Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 04/19] nvmem: Do not use DEVFS_IS_CHARACTER_DEV Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 05/19] common: firmware: Don't use FILE_SIZE_STREAM directly Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 06/19] devfs: Fix incorrect error check for cdev->ops->lseek() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 07/19] fs: Update FILE position in lseek() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 08/19] fs: Drop trivial .lseek() implementaitons in FS drivers Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 09/19] devfs: Drop dev_lseek_default() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 10/19] fs: devfs: Change .lseek callbacks to return 'int' Andrey Smirnov
2019-02-04 14:32 ` Sascha Hauer
2019-01-29 6:55 ` [PATCH v2 11/19] fs: Do not use IS_ERR_VALUE() to validate offset in lseek() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 12/19] fs: Simplify new position calculation " Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 13/19] fs: Share code between mem_write()/mem_read() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 14/19] fs: Avoid division in mem_copy() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 15/19] fs: Report actual data processed by mem_copy() Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 16/19] fs: Introduce mem_read_nofail() Andrey Smirnov
2019-01-29 6:55 ` Andrey Smirnov [this message]
2019-02-04 13:57 ` [PATCH v2 17/19] commands: md: Do not use memmap() Sascha Hauer
2019-02-04 19:35 ` Andrey Smirnov
2019-01-29 6:55 ` [PATCH v2 18/19] drivers: mem: Create file to access second half of 64-bit memory Andrey Smirnov
2019-01-29 8:48 ` Sascha Hauer
2019-01-29 20:40 ` Andrey Smirnov
2019-01-29 21:09 ` Sam Ravnborg
2019-01-31 10:54 ` Peter Mamonov
2019-01-31 12:50 ` Peter Mamonov
2019-02-01 7:47 ` Sascha Hauer
2019-02-01 10:25 ` Peter Mamonov
2019-02-02 1:07 ` Andrey Smirnov
2019-02-02 0:35 ` Andrey Smirnov
2019-02-04 7:40 ` Sascha Hauer
2019-01-31 20:17 ` Andrey Smirnov
2019-02-01 10:14 ` Peter Mamonov
2019-01-29 6:55 ` [PATCH v2 19/19] libfile: Fix incorrect lseek check in open_and_lseek() Andrey Smirnov
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