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authorStephen Boyd <swboyd@chromium.org>2019-09-25 16:46:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-25 17:51:39 -0700
commit091cb0994edd20d67521094ac9c6ec9804058d9a (patch)
tree373257c717a097a91f987d667cf7d5ef20642b49 /include/linux
parent8e72a7a44df5534ae7664240c1fa75e71e11c64a (diff)
lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds
I'm seeing a bunch of debug prints from a user of print_hex_dump_bytes() in my kernel logs, but I don't have CONFIG_DYNAMIC_DEBUG enabled nor do I have DEBUG defined in my build. The problem is that print_hex_dump_bytes() calls a wrapper function in lib/hexdump.c that calls print_hex_dump() with KERN_DEBUG level. There are three cases to consider here 1. CONFIG_DYNAMIC_DEBUG=y --> call dynamic_hex_dum() 2. CONFIG_DYNAMIC_DEBUG=n && DEBUG --> call print_hex_dump() 3. CONFIG_DYNAMIC_DEBUG=n && !DEBUG --> stub it out Right now, that last case isn't detected and we still call print_hex_dump() from the stub wrapper. Let's make print_hex_dump_bytes() only call print_hex_dump_debug() so that it works properly in all cases. Case #1, print_hex_dump_debug() calls dynamic_hex_dump() and we get same behavior. Case #2, print_hex_dump_debug() calls print_hex_dump() with KERN_DEBUG and we get the same behavior. Case #3, print_hex_dump_debug() is a nop, changing behavior to what we want, i.e. print nothing. Link: http://lkml.kernel.org/r/20190816235624.115280-1-swboyd@chromium.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/printk.h22
1 files changed, 15 insertions, 7 deletions
diff --git a/include/linux/printk.h b/include/linux/printk.h
index cefd374c47b1..c09d67edda3a 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -488,13 +488,6 @@ extern int hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
extern void print_hex_dump(const char *level, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
const void *buf, size_t len, bool ascii);
-#if defined(CONFIG_DYNAMIC_DEBUG)
-#define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
- dynamic_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true)
-#else
-extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
- const void *buf, size_t len);
-#endif /* defined(CONFIG_DYNAMIC_DEBUG) */
#else
static inline void print_hex_dump(const char *level, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
@@ -526,4 +519,19 @@ static inline void print_hex_dump_debug(const char *prefix_str, int prefix_type,
}
#endif
+/**
+ * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
+ * @prefix_str: string to prefix each line with;
+ * caller supplies trailing spaces for alignment if desired
+ * @prefix_type: controls whether prefix of an offset, address, or none
+ * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ *
+ * Calls print_hex_dump(), with log level of KERN_DEBUG,
+ * rowsize of 16, groupsize of 1, and ASCII output included.
+ */
+#define print_hex_dump_bytes(prefix_str, prefix_type, buf, len) \
+ print_hex_dump_debug(prefix_str, prefix_type, 16, 1, buf, len, true)
+
#endif

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