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[PATCH 2/3] Modify %M directive to support variable width.
- From: Wenji Huang <wenji dot huang at oracle dot com>
- To: systemtap at sourceware dot org
- Cc: Wenji Huang <wenji dot huang at oracle dot com>
- Date: Fri, 24 Apr 2009 13:23:36 -0400
- Subject: [PATCH 2/3] Modify %M directive to support variable width.
This patch will make %M directive dump the variable width
buffer in hex format instead of returning uint64_t number
as before.
* runtime/vsprintf.c: Modify %M directive.
* stap.1.in: Update description.
* testsuite/systemtap.printf/memory1.stp: Add test case.
---
runtime/vsprintf.c | 31 ++++++++++++++++++++-----------
stap.1.in | 2 +-
testsuite/systemtap.printf/memory1.stp | 14 ++++++++++++++
3 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/runtime/vsprintf.c b/runtime/vsprintf.c
index 38ab0e2..549f209 100644
--- a/runtime/vsprintf.c
+++ b/runtime/vsprintf.c
@@ -361,18 +361,16 @@ static int _stp_vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
else
len = 1;
+ if (*fmt_copy == 'M')
+ len = len * 2; /* hex dump print size */
+
if (!(flags & STP_LEFT)) {
while (len < field_width--) {
num_bytes++;
}
}
- if (*fmt_copy == 'M') {
- num_bytes += number_size((unsigned long) *(uint64_t *) s,
- 16, field_width, len, flags);
- }
- else {
- num_bytes += len;
- }
+
+ num_bytes += len;
while (len < field_width--) {
num_bytes++;
@@ -636,16 +634,27 @@ static int _stp_vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
len = 1;
if (!(flags & STP_LEFT)) {
- while (len < field_width--) {
+ int actlen = len;
+ if (*fmt == 'M')
+ actlen = len * 2;
+ while (actlen < field_width--) {
if (str <= end)
*str = ' ';
++str;
}
}
if (*fmt == 'M') {
- str = number(str, str + len - 1 < end ? str + len - 1 : end,
- (unsigned long) *(uint64_t *) s,
- 16, field_width, len, flags);
+ const char _stp_hex_asc[] = "0123456789abcdef";
+ int j;
+ #define _stp_hex_asc_lo(x) _stp_hex_asc[((x) & 0x0f)]
+ #define _stp_hex_asc_hi(x) _stp_hex_asc[((x) & 0xf0) >> 4]
+ for (i = 0, j = 0; i < len; i++) {
+ *str = _stp_hex_asc_hi(*s);
+ str++;
+ *str = _stp_hex_asc_lo(*s);
+ str++; s++;
+ }
+ len = len * 2; /* the actual length */
}
else {
for (i = 0; i < len; ++i) {
diff --git a/stap.1.in b/stap.1.in
index aed473d..a8609d6 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -674,7 +674,7 @@ Signed decimal.
Safely reads kernel memory at the given address, outputs its content. The precision specifier determines the number of bytes to read. Default is 1 byte.
.TP
%M
-Same as %m, but outputs in hexadecimal. The precision specifier determines the number of hexadecimal digits to output. Default is 1 digit.
+Same as %m, but outputs in hexadecimal. The minimal size of output is double the precision specifier.
.TP
%o
Unsigned octal.
diff --git a/testsuite/systemtap.printf/memory1.stp b/testsuite/systemtap.printf/memory1.stp
index f9cbf60..93a4edf 100644
--- a/testsuite/systemtap.printf/memory1.stp
+++ b/testsuite/systemtap.printf/memory1.stp
@@ -113,6 +113,20 @@ probe syscall.open {
success = 0;
}
+ expected_16_actual = sprintf (" %x%x%x%x%x%x",
+ chrofstr(filename, 0),
+ chrofstr(filename, 1),
+ chrofstr(filename, 2),
+ chrofstr(filename, 3),
+ chrofstr(filename, 4),
+ chrofstr(filename, 5));
+ testName = "%M dynamic width larger than dynamic precision";
+ result = sprintf ("%*.*M", 14, 6, $filename);
+ if (result != expected_16_actual) {
+ printf ("Test %s failed\n", testName);
+ success = 0;
+ }
+
if (success)
print ("Test passed\n");
--
1.5.6