[PATCH v3 3/7] log: append printk safe buffer output to 'log'

["shogo.matsumoto@xxxxxxxxxxx" <shogo.matsumoto@xxxxxxxxxxx>]

Output of 'log' compared to 'log -s':
- Suppress struct header (len, addr, message_lost...)
- Display only non-empty buffers
- Display buffer name at the beginning of line

Signed-off-by: Shogo Matsumoto <shogo.matsumoto@xxxxxxxxxxx>
---
 kernel.c | 43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/kernel.c b/kernel.c
index 57fe355..138ac3c 100644
--- a/kernel.c
+++ b/kernel.c
@@ -5057,6 +5057,7 @@ cmd_log(void)
 	}
 
 	dump_log(msg_flags);
+	dump_printk_safe_seq_buf(msg_flags);
 }
 
 
@@ -11561,6 +11562,9 @@ __dump_printk_safe_seq_buf(char *buf_name, int msg_flags)
 	int cpu, buffer_size;
 	char *buffer;
 	ulong base_addr, len_addr, message_lost_addr, buffer_addr;
+	bool show_header;
+
+	show_header = msg_flags & SHOW_LOG_SAFE;
 
 	if (!symbol_exists(buf_name)) {
 		return;
@@ -11576,7 +11580,8 @@ __dump_printk_safe_seq_buf(char *buf_name, int msg_flags)
 	buffer_size = SIZE(printk_safe_seq_buf_buffer);
 	buffer = GETBUF(buffer_size);
 
-	fprintf(fp, "PRINTK_SAFE_SEQ_BUF: %s\n", buf_name);
+	if (show_header)
+		fprintf(fp, "PRINTK_SAFE_SEQ_BUF: %s\n", buf_name);
 	for (cpu = 0; cpu < kt->cpus; cpu++) {
 		int len, message_lost;
 		ulong per_cpu_offset;
@@ -11584,17 +11589,26 @@ __dump_printk_safe_seq_buf(char *buf_name, int msg_flags)
 
 		readmem(len_addr + per_cpu_offset, KVADDR, &len, sizeof(int),
 			"printk_safe_seq_buf len", FAULT_ON_ERROR);
-		readmem(message_lost_addr + per_cpu_offset, KVADDR,
-			&message_lost, sizeof(int),
-			"printk_safe_seq_buf message_lost", FAULT_ON_ERROR);
-		fprintf(fp, "CPU: %d  ADDR: %lx LEN: %d  MESSAGE_LOST: %d\n",
-			cpu, base_addr + per_cpu_offset, len, message_lost);
+
+		if (show_header) {
+			readmem(message_lost_addr + per_cpu_offset, KVADDR,
+				&message_lost, sizeof(int),
+				"printk_safe_seq_buf message_lost", FAULT_ON_ERROR);
+			fprintf(fp, "CPU: %d  ADDR: %lx LEN: %d  MESSAGE_LOST: %d\n",
+				cpu, base_addr + per_cpu_offset, len, message_lost);
+		}
 
 		if (len > 0) {
-			int i, n;
+			int i, n, ilen;
 			char *p;
 			bool start_of_line;
 
+			ilen = 0;
+			if (show_header) {
+				ilen = PRINTK_SAFE_SEQ_BUF_INDENT;
+			} else {
+				ilen = strlen(buf_name) + 3; // "[%s] "
+			}
 			readmem(buffer_addr + per_cpu_offset, KVADDR,
 				buffer, buffer_size,
 				"printk_safe_seq_buf buffer", FAULT_ON_ERROR);
@@ -11610,12 +11624,15 @@ __dump_printk_safe_seq_buf(char *buf_name, int msg_flags)
 					if (!sol)
 						fprintf(fp, "\n");
 
-					fprintf(fp, space(PRINTK_SAFE_SEQ_BUF_INDENT));
+					if (show_header)
+						fprintf(fp, space(PRINTK_SAFE_SEQ_BUF_INDENT));
+					else
+						fprintf(fp, "[%s] ", buf_name);
 
 					continue;
 				} else {
 					if (sol)
-						fprintf(fp, "%s", space(PRINTK_SAFE_SEQ_BUF_INDENT));
+						fprintf(fp, "%s", space(ilen));
 
 					if (isprint(*p) || isspace(*p)) {
 						fputc(*p, fp);
@@ -11628,8 +11645,9 @@ __dump_printk_safe_seq_buf(char *buf_name, int msg_flags)
 			}
 			if (!start_of_line)
 				fputc('\n', fp);
-			fputc('\n', fp);
-		} else {
+			if (show_header)
+				fputc('\n', fp);
+		} else if (show_header) {
 			fprintf(fp, "%s(empty)\n\n", space(PRINTK_SAFE_SEQ_BUF_INDENT));
 		}
 	}
@@ -11660,7 +11678,8 @@ dump_printk_safe_seq_buf(int msg_flags)
 	    INVALID_MEMBER(printk_safe_seq_buf_message_lost) ||
 	    INVALID_MEMBER(printk_safe_seq_buf_buffer) ||
 	    INVALID_SIZE(printk_safe_seq_buf_buffer)) {
-		error(INFO, "-s not supported with this kernel version\n");
+		if (msg_flags & SHOW_LOG_SAFE)
+			error(INFO, "-s not supported with this kernel version\n");
 		return;
 	}
 
-- 
2.29.2


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