seq_file: provide an analogue of print_hex_dump()

This introduces a new helper and switches current users to use it.  All
patches are compiled tested. kmemleak is tested via its own test suite.

This patch (of 6):

The new seq_hex_dump() is a complete analogue of print_hex_dump().

We have few users of this functionality already. It allows to reduce their
codebase.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Tadeusz Struk <tadeusz.struk@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/fs/seq_file.c b/fs/seq_file.c
index ce9e39fd5daf..263b125dbcf4 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/cred.h>
 #include <linux/mm.h>
+#include <linux/printk.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -773,6 +774,47 @@ void seq_pad(struct seq_file *m, char c)
 }
 EXPORT_SYMBOL(seq_pad);
 
+/* A complete analogue of print_hex_dump() */
+void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
+                  int rowsize, int groupsize, const void *buf, size_t len,
+                  bool ascii)
+{
+        const u8 *ptr = buf;
+        int i, linelen, remaining = len;
+        int ret;
+
+        if (rowsize != 16 && rowsize != 32)
+                rowsize = 16;
+
+        for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) {
+                linelen = min(remaining, rowsize);
+                remaining -= rowsize;
+
+                switch (prefix_type) {
+                case DUMP_PREFIX_ADDRESS:
+                        seq_printf(m, "%s%p: ", prefix_str, ptr + i);
+                        break;
+                case DUMP_PREFIX_OFFSET:
+                        seq_printf(m, "%s%.8x: ", prefix_str, i);
+                        break;
+                default:
+                        seq_printf(m, "%s", prefix_str);
+                        break;
+                }
+
+                ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
+                                         m->buf + m->count, m->size - m->count,
+                                         ascii);
+                if (ret >= m->size - m->count) {
+                        seq_set_overflow(m);
+                } else {
+                        m->count += ret;
+                        seq_putc(m, '\n');
+                }
+        }
+}
+EXPORT_SYMBOL(seq_hex_dump);
+
 struct list_head *seq_list_start(struct list_head *head, loff_t pos)
 {
         struct list_head *lh;