[LTP] [PATCH v2 1/2] syscalls/cma: test case should return TCONF if syscall doesn't exist

Jan Stancek
2019-02-15T13:53:29Z

----- Original Message -----

> Hi Jason,

> A new failure was occured after applying this new patch.

> From our observation, the latest process_vm_readv03.c failed with
> process_vm_readv() Invalid argument error on rhel7.3 platfrom. We suspect
> that this problem maybe caused by glibc or compiler, because if compile the
> test program with -O0 it get pass, but with the ltp default optimization -O2
> it get fail. Also, if we revert this new patch, the test PASS whatever with
> -O2 and -O0, that's very strange.

One difference is that the extra function promoted int to long.
Can you try with patch below? (Note that I dropped also root requirement, man page
says that it has same requirements as ptrace - you should be able to read from processes you own)

Regards,
Jan

diff --git a/testcases/kernel/syscalls/cma/process_vm_readv03.c b/testcases/kernel/syscalls/cma/process_vm_readv03.c
index 45f7c92e499c..1cec442b3456 100644
--- a/testcases/kernel/syscalls/cma/process_vm_readv03.c
+++ b/testcases/kernel/syscalls/cma/process_vm_readv03.c
@@ -181,7 +181,7 @@ static long *fetch_remote_addrs(void)
remote.iov_len = len;

TEST(ltp_syscall(__NR_process_vm_readv, pids[0], &local,
- 1, &remote, 1, 0));
+ 1, &remote, 1, 0L));
if (TEST_RETURN != len)
tst_brkm(TFAIL | TERRNO, tst_exit, "process_vm_readv");

@@ -214,7 +214,7 @@ static void child_invoke(int *bufsz_arr)
NUM_LOCAL_VECS);

TEST(ltp_syscall(__NR_process_vm_readv, pids[0], local, NUM_LOCAL_VECS,
- remote, nr_iovecs, 0));
+ remote, nr_iovecs, 0L));
if (TEST_RETURN != bufsz)
tst_brkm(TBROK | TERRNO, tst_exit, "process_vm_readv");

@@ -245,10 +245,8 @@ static void child_invoke(int *bufsz_arr)

static void setup(void)
{
- tst_require_root();
-
/* Just a sanity check of the existence of syscall */
- ltp_syscall(__NR_process_vm_readv, getpid(), NULL, 0, NULL, 0, 0);
+ ltp_syscall(__NR_process_vm_readv, getpid(), NULL, 0, NULL, 0, 0L);

nr_iovecs = nflag ? SAFE_STRTOL(NULL, nr_opt, 1, IOV_MAX) : 10;
bufsz = sflag ? SAFE_STRTOL(NULL, sz_opt, NUM_LOCAL_VECS, LONG_MAX)

> --------------------------------
> # gcc -g -O2 -g -O2 -fno-strict-aliasing -pipe -Wall -W
> -Wold-style-definition -D_FORTIFY_SOURCE=2 -I../../../../include
> -I../../../../include -I../../../../include/old/ -L../../../../lib
> process_vm_readv03.c -lltp -o process_vm_readv03_O2

> # ./process_vm_readv03_O2
> process_vm_readv03 0 TINFO : child 0: 10 iovecs allocated and initialized.
> process_vm_readv03 0 TINFO : child 1: 10 remote iovecs received.
> process_vm_readv03 0 TINFO : child 1: 4 local iovecs initialized.
> process_vm_readv03 1 TBROK : process_vm_readv03.c:220: process_vm_readv:
> errno=EINVAL(22): Invalid argument
> process_vm_readv03 2 TBROK : process_vm_readv03.c:220: Remaining cases broken
> process_vm_readv03 1 TFAIL : process_vm_readv03.c:103: child 1 returns 512

> # strace -f ./process_vm_readv03_O2
> ...
> [pid 14676] process_vm_readv(14675, 0x7ffe40232ea0, 4, 0x7640c0, 10,
> 140728898420736) = -1 EINVAL (Invalid argument)
> [pid 14676] write(1, "process_vm_readv03 1 \33[1;31m"...,
> 125process_vm_readv03 1 TBROK : process_vm_readv03.c:220: process_vm_readv:
> errno=EINVAL(22): Invalid argument
> ) = 125
> ...

> --------------------------------------------
> # gcc -g -O0 -g -O0 -fno-strict-aliasing -pipe -Wall -W
> -Wold-style-definition -D_FORTIFY_SOURCE=2 -I../../../../include
> -I../../../../include -I../../../../include/old/ -L../../../../lib
> process_vm_readv03.c -lltp -o process_vm_readv03_O0

> # ./process_vm_readv03_O0
> process_vm_readv03 0 TINFO : child 0: 10 iovecs allocated and initialized.
> process_vm_readv03 0 TINFO : child 1: 10 remote iovecs received.
> process_vm_readv03 0 TINFO : child 1: 4 local iovecs initialized.
> process_vm_readv03 1 TPASS : child 1: all bytes are correctly received.

> # strace -f ./process_vm_readv03_O0
> ...
> [pid 14703] process_vm_readv(14702,
> [{"\0\1\2\3\4\5\6\7\10\t\n\v\f\r\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37"...,
> 43269},
> {"\5\6\7\10\t\n\v\f\r\16\17\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37
> !\"#$"..., 18907},
> {"\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377"...,
> 3203}, {"cdefghijklmnopqrstuvwxyz{|}~\177\200\201\202"..., 34621}], 4,
> [{0x9570c0, 24638}, {0x95d110, 35640}, {0x965c50, 19802}, {0x96a9c0, 490},
> {0x96abc0, 8624}, {0x96cd80, 3571}, {0x96db80, 2114}, {0x96e3d0, 2374},
> {0x96ed20, 1139}, {0x96f1a0, 1608}], 10, 0) = 100000
> [pid 14703] write(1, "process_vm_readv03 1 \33[1;32m"...,
> 89process_vm_readv03 1 TPASS : child 1: all bytes are correctly received.
> ) = 89
> ...

> # uname -r
> 3.10.0-514.55.4.el7.x86_64

> # rpm -q glibc
> glibc-2.17-157.el7_3.5.x86_64

> --
> Regards,
> Li Wang
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