linux-ext4 - [PATCH v4 1/7] tracing: add __print_flags

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-Id: <1484085142-2297-2-git-send-email-ross.zwisler@linux.intel.com>
Date:   Tue, 10 Jan 2017 14:52:16 -0700
From:   Ross Zwisler <ross.zwisler@...ux.intel.com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org
Cc:     Ross Zwisler <ross.zwisler@...ux.intel.com>,
        "Darrick J. Wong" <darrick.wong@...cle.com>,
        "Theodore Ts'o" <tytso@....edu>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Christoph Hellwig <hch@....de>,
        Dan Williams <dan.j.williams@...el.com>,
        Ingo Molnar <mingo@...hat.com>, Jan Kara <jack@...e.cz>,
        Matthew Wilcox <mawilcox@...rosoft.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-mm@...ck.org, linux-nvdimm@...ts.01.org,
        linux-xfs@...r.kernel.org
Subject: [PATCH v4 1/7] tracing: add __print_flags_u64()

Add __print_flags_u64() and the helper trace_print_flags_seq_u64() in the
same spirit as __print_symbolic_u64() and trace_print_symbols_seq_u64().
These functions allow us to print symbols associated with flags that are 64
bits wide even on 32 bit machines.

These will be used by the DAX code so that we can print the flags set in a
pfn_t such as PFN_SG_CHAIN, PFN_SG_LAST, PFN_DEV and PFN_MAP.

Without this new function I was getting errors like the following when
compiling for i386:

./include/linux/pfn_t.h:13:22: warning: large integer implicitly truncated
to unsigned type [-Woverflow]
 #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
  ^

Signed-off-by: Ross Zwisler <ross.zwisler@...ux.intel.com>
Reviewed-by: Steven Rostedt <rostedt@...dmis.org>
---
 include/linux/trace_events.h |  4 ++++
 include/trace/trace_events.h | 11 +++++++++++
 kernel/trace/trace_output.c  | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index be00761..db2c3ba 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -23,6 +23,10 @@ const char *trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 				    const struct trace_print_flags *symbol_array);
 
 #if BITS_PER_LONG == 32
+const char *trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
+		      unsigned long long flags,
+		      const struct trace_print_flags_u64 *flag_array);
+
 const char *trace_print_symbols_seq_u64(struct trace_seq *p,
 					unsigned long long val,
 					const struct trace_print_flags_u64
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 467e12f..c6e9f72 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -283,8 +283,16 @@ TRACE_MAKE_SYSTEM_STR();
 		trace_print_symbols_seq(p, value, symbols);		\
 	})
 
+#undef __print_flags_u64
 #undef __print_symbolic_u64
 #if BITS_PER_LONG == 32
+#define __print_flags_u64(flag, delim, flag_array...)			\
+	({								\
+		static const struct trace_print_flags_u64 __flags[] =	\
+			{ flag_array, { -1, NULL } };			\
+		trace_print_flags_seq_u64(p, delim, flag, __flags);	\
+	})
+
 #define __print_symbolic_u64(value, symbol_array...)			\
 	({								\
 		static const struct trace_print_flags_u64 symbols[] =	\
@@ -292,6 +300,9 @@ TRACE_MAKE_SYSTEM_STR();
 		trace_print_symbols_seq_u64(p, value, symbols);	\
 	})
 #else
+#define __print_flags_u64(flag, delim, flag_array...)			\
+			__print_flags(flag, delim, flag_array)
+
 #define __print_symbolic_u64(value, symbol_array...)			\
 			__print_symbolic(value, symbol_array)
 #endif
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 5d33a73..5204485 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -124,6 +124,44 @@ EXPORT_SYMBOL(trace_print_symbols_seq);
 
 #if BITS_PER_LONG == 32
 const char *
+trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
+		      unsigned long long flags,
+		      const struct trace_print_flags_u64 *flag_array)
+{
+	unsigned long long mask;
+	const char *str;
+	const char *ret = trace_seq_buffer_ptr(p);
+	int i, first = 1;
+
+	for (i = 0;  flag_array[i].name && flags; i++) {
+
+		mask = flag_array[i].mask;
+		if ((flags & mask) != mask)
+			continue;
+
+		str = flag_array[i].name;
+		flags &= ~mask;
+		if (!first && delim)
+			trace_seq_puts(p, delim);
+		else
+			first = 0;
+		trace_seq_puts(p, str);
+	}
+
+	/* check for left over flags */
+	if (flags) {
+		if (!first && delim)
+			trace_seq_puts(p, delim);
+		trace_seq_printf(p, "0x%llx", flags);
+	}
+
+	trace_seq_putc(p, 0);
+
+	return ret;
+}
+EXPORT_SYMBOL(trace_print_flags_seq_u64);
+
+const char *
 trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 			 const struct trace_print_flags_u64 *symbol_array)
 {
-- 
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html