[DTrace-devel] [PATCH] test: Switch kernel pointer in tracemem() test
eugene.loh at oracle.com
eugene.loh at oracle.com
Mon Mar 6 21:14:20 UTC 2023
From: Eugene Loh <eugene.loh at oracle.com>
The tracemem() test dumped a portion of kernel memory, comparing
different tracemem() output for the same kernel memory for consistency.
Since it was looking at task_struct for the current thread, however,
the underlying data could conceivably change as the test ran, leading
to inconsistency and a false negative.
Change the kernel memory to be the first 14 bytes of 'linux_banner,
which should remain "Linux version ".
Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
test/unittest/tracemem/tst.tracemem.d | 58 +++++--------------------
test/unittest/tracemem/tst.tracemem.r | 31 +++++++++----
test/unittest/tracemem/tst.tracemem.r.p | 30 -------------
3 files changed, 34 insertions(+), 85 deletions(-)
delete mode 100755 test/unittest/tracemem/tst.tracemem.r.p
diff --git a/test/unittest/tracemem/tst.tracemem.d b/test/unittest/tracemem/tst.tracemem.d
index 41440518..202fb514 100644
--- a/test/unittest/tracemem/tst.tracemem.d
+++ b/test/unittest/tracemem/tst.tracemem.d
@@ -13,53 +13,19 @@
#pragma D option quiet
-long long *p;
-
BEGIN {
- /* pick some pointer to kernel memory */
- p = (long long *) curthread;
-
- /* dump memory at this pointer */
- printf("%16.16x %16.16x\n", p[ 0], p[ 1]);
- printf("%16.16x %16.16x\n", p[ 2], p[ 3]);
- printf("%16.16x %16.16x\n", p[ 4], p[ 5]);
- printf("%16.16x %16.16x\n", p[ 6], p[ 7]);
- printf("%16.16x %16.16x\n", p[ 8], p[ 9]);
- printf("%16.16x %16.16x\n", p[10], p[11]);
- printf("%16.16x %16.16x\n", p[12], p[13]);
- printf("%16.16x %16.16x\n", p[14], p[15]);
- printf("%16.16x %16.16x\n", p[16], p[17]);
- printf("%16.16x %16.16x\n", p[18], p[19]);
- printf("%16.16x %16.16x\n", p[20], p[21]);
- printf("%16.16x %16.16x\n", p[22], p[23]);
- printf("%16.16x %16.16x\n", p[24], p[25]);
- printf("%16.16x %16.16x\n", p[26], p[27]);
- printf("%16.16x %16.16x\n", p[28], p[29]);
- printf("%16.16x %16.16x\n", p[30], p[31]);
-
- /* try tracemem() with this same pointer but various sizes */
-
- tracemem(p, 256); /* 256 bytes */
-
- tracemem(p, 256, -1); /* 256 bytes (arg2 < 0) */
-
- tracemem(p, 256, 0); /* 0 bytes */
-
- tracemem(p, 256, 32); /* 32 bytes */
-
- tracemem(p, 256, 64); /* 64 bytes */
-
- tracemem(p, 256, 128); /* 128 bytes */
-
- tracemem(p, 256, 256); /* 256 bytes */
-
- tracemem(p, 256, 320); /* 256 bytes (arg1 <= arg2) */
-
- tracemem(p, 256, (unsigned char) 0x80);
- /* 128 bytes */
-
- tracemem(p, 256, (signed char) 0x80);
- /* 256 bytes (arg2 < 0) */
+ /* p = `linux_banner; */ /* first 14 chars are "Linux version " */
+
+ /* try tracemem() with various sizes */
+
+ tracemem(`linux_banner, 14); /* "Linux version ": 14 bytes */
+ tracemem(`linux_banner, 14, -1); /* "Linux version ": 14 bytes (arg2 < 0) */
+ tracemem(`linux_banner, 14, 0); /* 0 bytes */
+ tracemem(`linux_banner, 14, 2); /* "Li" : 2 bytes */
+ tracemem(`linux_banner, 14, 7); /* "Linux v" : 7 bytes */
+ tracemem(`linux_banner, 14, 12); /* "Linux versio" : 12 bytes */
+ tracemem(`linux_banner, 14, 14); /* "Linux version ": 14 bytes */
+ tracemem(`linux_banner, 14, 15); /* "Linux version ": 14 bytes (arg1 <= arg2) */
exit(0);
}
diff --git a/test/unittest/tracemem/tst.tracemem.r b/test/unittest/tracemem/tst.tracemem.r
index 1b24115f..2952158d 100644
--- a/test/unittest/tracemem/tst.tracemem.r
+++ b/test/unittest/tracemem/tst.tracemem.r
@@ -1,9 +1,22 @@
-256 bytes
-256 bytes
-32 bytes
-64 bytes
-128 bytes
-256 bytes
-256 bytes
-128 bytes
-256 bytes
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 65 72 73 69 6f 6e 20 Linux version
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 65 72 73 69 6f 6e 20 Linux version
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 Li
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 Linux v
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 65 72 73 69 6f Linux versio
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 65 72 73 69 6f 6e 20 Linux version
+
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
+ 0: 4c 69 6e 75 78 20 76 65 72 73 69 6f 6e 20 Linux version
+
diff --git a/test/unittest/tracemem/tst.tracemem.r.p b/test/unittest/tracemem/tst.tracemem.r.p
deleted file mode 100755
index 3f34b26b..00000000
--- a/test/unittest/tracemem/tst.tracemem.r.p
+++ /dev/null
@@ -1,30 +0,0 @@
-#!/usr/bin/gawk -f
-
-# read data against which we will check tracemem() results
-BEGIN {
- n = 0; # count check results
- m = 0; # count tracemem() results
-}
-NF == 2 {
- check[n] = $1; n++;
- check[n] = $2; n++;
- next;
-}
-
-# if we have a blank line, report number of bytes compared, if any
-NF == 0 && m > 0 { print 8 * m, "bytes" }
-
-# restart counting tracemem() output
-NF == 0 { m = 0; next; }
-
-# comparison function
-function mycomp(expect, actual) {
- if ( expect != actual )
- print "ERROR: expect", expect, "actual", actual;
-}
-
-# tracemem output has two sets of 8 bytes each; reverse bytes for comparison
-/:/ {
- mycomp( check[m++], $9$8$7$6$5$4$3$2);
- mycomp( check[m++], $17$16$15$14$13$12$11$10);
-}
--
2.18.4
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