7:40 a.m.
On 32-bit arches, it's possible not only to request
-D_FILE_OFFSET_BITS=64 (which is always done with meson) but also
-D_TIME_BITS=64. With glibc, both of these affect what variant of
stat() or lstat() is called. With 64 bit time it's:
__stat64_time64() or __lstat64_time64(), respectively.
Fortunately, no other variant (__xstat(), __xstat64()) has
_time64 alternative and thus does not need similar treatment.
Similarly, musl is not affected by this.
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/404
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
Mind you, after this I still see two tests failing:
1) virnettlscontexttest
2) virnettlssessiontest
But I believe the problem is that GnuTLS on my 32bit RPi was not built
with -D_TIME_BITS=64 and thus when generating certificates and setting
their activation/expiry times I get the following errors:
TEST: virnettlscontexttest
1) TLS Context cacertreq.filename + servercertreq.filename ... libvirt: XML-RPC
error : The server certificate servercertreq-ctx.pem is not yet active
FAILED
TEST: virnettlssessiontest
1) TLS Session servercertreq.filename + clientcertreq.filename ... libvirt: XML-RPC
error : authentication failed: Failed to verify peer's certificate
FAILED
Setting of activation/expiry times is done by calling:
1) gnutls_x509_crt_set_activation_time(..., time_t act_time)
2) gnutls_x509_crt_set_expiration_time(..., time_t exp_time)
And this is how calling the first looks under disassembly:
7428: e51b1128 ldr r1, [fp, #-296] ; 0xfffffed8
742c: e14b2dd4 ldrd r2, [fp, #-212] ; 0xffffff2c
7430: e1a00001 mov r0, r1
7434: ebfff23d bl 3d30
<gnutls_x509_crt_set_activation_time@plt>
Now, ldrd instruction modifies both r2 and r3 by loading 4+4 bytes from
a memory address [1]. But the first thing that
gnutls_x509_crt_set_activation_time() does is overwriting r3 register:
000fb4a0 <gnutls_x509_crt_set_activation_time>:
fb4a0: e52de004 push {lr} ; (str lr, [sp, #-4]!)
fb4a4: e250c000 subs ip, r0, #0
fb4a8: e59f3080 ldr r3, [pc, #128] ; fb530
<gnutls_x509_crt_set_activation_time+0x90>
fb4ac: e24dd00c sub sp, sp, #12
fb4b0: e08f3003 add r3, pc, r3
fb4b4: 0a000009 beq fb4e0
<gnutls_x509_crt_set_activation_time+0x40>
With 32-bit time_t the disassembly looks a bit different:
73e4: e51b3114 ldr r3, [fp, #-276] ; 0xfffffeec
73e8: e51b10f4 ldr r1, [fp, #-244] ; 0xffffff0c
73ec: e1a00003 mov r0, r3
73f0: ebfff250 bl 3d38
<gnutls_x509_crt_set_activation_time@plt>
1: It should be 'ldrd r2, r3, $memAddr' but the second register is
implied by the first one, so it can be shortened:
https://developer.arm.com/documentation/ddi0406/c/Application-Level-Archi...
tests/virmockstathelpers.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/tests/virmockstathelpers.c b/tests/virmockstathelpers.c
index 39e270eaac..5b1f3b08a7 100644
--- a/tests/virmockstathelpers.c
+++ b/tests/virmockstathelpers.c
@@ -54,6 +54,10 @@
* Unfortunately, because we are trying to mock replace the C library,
* we need to know about this internal impl detail.
*
+ * Furthermore, support for 64-bit time can be enabled, which on 32-bit
+ * systems with glibc overwrites stat64() to __stat64_time64() and lstat64()
+ * to __lstat64_time64().
+ *
* On macOS stat() and lstat() are resolved to _stat$INODE64 and
* _lstat$INODE64, respectively. stat(2) man page also declares that
* stat64(), lstat64() and fstat64() are deprecated, and when
@@ -168,7 +172,11 @@ static void virMockStatInit(void)
fdebug("real stat %p\n", real_stat);
#endif
#ifdef MOCK_STAT64
+# if defined(__GLIBC__) && defined(_TIME_BITS) && _TIME_BITS == 64
+ VIR_MOCK_REAL_INIT_ALIASED(stat64, "__stat64_time64");
+# else
VIR_MOCK_REAL_INIT(stat64);
+# endif
fdebug("real stat64 %p\n", real_stat64);
#endif
#ifdef MOCK___XSTAT
@@ -188,7 +196,11 @@ static void virMockStatInit(void)
fdebug("real lstat %p\n", real_lstat);
#endif
#ifdef MOCK_LSTAT64
+# if defined(__GLIBC__) && defined(_TIME_BITS) && _TIME_BITS == 64
+ VIR_MOCK_REAL_INIT_ALIASED(lstat64, "__lstat64_time64");
+# else
VIR_MOCK_REAL_INIT(lstat64);
+# endif
fdebug("real lstat64 %p\n", real_lstat64);
#endif
#ifdef MOCK___LXSTAT
--
2.37.4