Qemu includes the glibc headers for the host defines and target headers are
part of the qemu source themselves. The glibc has the F_GETLK64, F_SETLK64
and F_SETLKW64 defined to 12, 13 and 14 for all archs in
sysdeps/unix/sysv/linux/bits/fcntl-linux.h. The linux kernel generic
definition for F_*LK is 5, 6 & 7 and F_*LK64* is 12,13, and 14 as seen in
include/uapi/asm-generic/fcntl.h. On 64bit machine, by default the kernel
assumes all F_*LK to 64bit calls and doesnt support use of F_*LK64* as
can be seen in include/linux/fcntl.h in linux source.
On x86_64 host, the values for F_*LK64* are set to 5, 6 and 7
explicitly in /usr/include/x86_64-linux-gnu/bits/fcntl.h by the glibc.
Whereas, a PPC64 host doesn't have such a definition in
/usr/include/powerpc64le-linux-gnu/bits/fcntl.h by the glibc. So,
the sources on PPC64 host sees the default value of F_*LK64*
as 12, 13 & 14(fcntl-linux.h).
Since the 64bit kernel doesnt support 12, 13 & 14; the glibc fcntl syscall
implementation(__libc_fcntl*(), __fcntl64_nocancel) does the F_*LK64* value
convertion back to F_*LK* values on PPC64 as seen in
sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h with FCNTL_ADJUST_CMD()
macro. Whereas on x86_64 host the values for F_*LK64* are set to 5, 6 and 7
and no adjustments are needed.
Since qemu doesnt use the glibc fcntl, but makes the safe_syscall* on its
own, the PPC64 qemu is calling the syscall with 12, 13, and 14(without
adjustment) and they all fail. The fcntl calls to F_GETLK/F_SETLK|W all
fail by all pplications run on PPC64 host user emulation.
The fix here could be to see why on PPC64 the glibc is still keeping
F_*LK64* different from F_*LK and why adjusting them to 5, 6 and 7 before
the syscall for PPC only. See if we can make the
/usr/include/powerpc64le-linux-gnu/bits/fcntl.h to have the values
5, 6 & 7 just like x86_64 and remove the adjustment code in glibc. That
way, qemu sources see the kernel supported values in glibc headers.
OR
On PPC64 host, qemu sources see both F_*LK & F_*LK64* as same and set to
12, 13 and 14 because __USE_FILE_OFFSET64 is defined in qemu
sources(also refer sysdeps/unix/sysv/linux/bits/fcntl-linux.h).
Do the value adjustment just like it is done by glibc source by using
F_GETLK value of 5. That way, we make the syscalls with the actual
supported values in Qemu. The patch is taking this approach.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
---
v3 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02923.html
Changes from v3:
- Fixed the tabs for case statements
- Addressed the comments on v3 wrt to the variable initialisation
and break from default case.
v2 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02920.html
Changes from v2:
- Fixed the braces, and indentation for comments.
v1 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02567.html
Changes from v1:
- Changed the overwrite of F*LK64* with 5, 6 and 7 in using #define
instead using the adjustment code similar to glibc as suggested.
- Dropped __linux__ check for the adjustment code as suggested.
- Moved the adjustment code inside target_to_host_fcntl_cmd to address
all possible|future cases.
linux-user/syscall.c | 126 ++++++++++++++++++++++++++++++++------------------
1 file changed, 80 insertions(+), 46 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 643b8833de..b5274f657a 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6475,63 +6475,97 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp,
/* warning : doesn't handle linux specific flags... */
static int target_to_host_fcntl_cmd(int cmd)
{
+ int ret;
+
switch(cmd) {
- case TARGET_F_DUPFD:
- case TARGET_F_GETFD:
- case TARGET_F_SETFD:
- case TARGET_F_GETFL:
- case TARGET_F_SETFL:
- return cmd;
- case TARGET_F_GETLK:
- return F_GETLK64;
- case TARGET_F_SETLK:
- return F_SETLK64;
- case TARGET_F_SETLKW:
- return F_SETLKW64;
- case TARGET_F_GETOWN:
- return F_GETOWN;
- case TARGET_F_SETOWN:
- return F_SETOWN;
- case TARGET_F_GETSIG:
- return F_GETSIG;
- case TARGET_F_SETSIG:
- return F_SETSIG;
+ case TARGET_F_DUPFD:
+ case TARGET_F_GETFD:
+ case TARGET_F_SETFD:
+ case TARGET_F_GETFL:
+ case TARGET_F_SETFL:
+ ret = cmd;
+ break;
+ case TARGET_F_GETLK:
+ ret = F_GETLK64;
+ break;
+ case TARGET_F_SETLK:
+ ret = F_SETLK64;
+ break;
+ case TARGET_F_SETLKW:
+ ret = F_SETLKW64;
+ break;
+ case TARGET_F_GETOWN:
+ ret = F_GETOWN;
+ break;
+ case TARGET_F_SETOWN:
+ ret = F_SETOWN;
+ break;
+ case TARGET_F_GETSIG:
+ ret = F_GETSIG;
+ break;
+ case TARGET_F_SETSIG:
+ ret = F_SETSIG;
+ break;
#if TARGET_ABI_BITS == 32
- case TARGET_F_GETLK64:
- return F_GETLK64;
- case TARGET_F_SETLK64:
- return F_SETLK64;
- case TARGET_F_SETLKW64:
- return F_SETLKW64;
-#endif
- case TARGET_F_SETLEASE:
- return F_SETLEASE;
- case TARGET_F_GETLEASE:
- return F_GETLEASE;
+ case TARGET_F_GETLK64:
+ ret = F_GETLK64;
+ break;
+ case TARGET_F_SETLK64:
+ ret = F_SETLK64;
+ break;
+ case TARGET_F_SETLKW64:
+ ret = F_SETLKW64;
+ break;
+#endif
+ case TARGET_F_SETLEASE:
+ ret = F_SETLEASE;
+ break;
+ case TARGET_F_GETLEASE:
+ ret = F_GETLEASE;
+ break;
#ifdef F_DUPFD_CLOEXEC
- case TARGET_F_DUPFD_CLOEXEC:
- return F_DUPFD_CLOEXEC;
+ case TARGET_F_DUPFD_CLOEXEC:
+ ret = F_DUPFD_CLOEXEC;
+ break;
#endif
- case TARGET_F_NOTIFY:
- return F_NOTIFY;
+ case TARGET_F_NOTIFY:
+ ret = F_NOTIFY;
+ break;
#ifdef F_GETOWN_EX
- case TARGET_F_GETOWN_EX:
- return F_GETOWN_EX;
+ case TARGET_F_GETOWN_EX:
+ ret = F_GETOWN_EX;
+ break;
#endif
#ifdef F_SETOWN_EX
- case TARGET_F_SETOWN_EX:
- return F_SETOWN_EX;
+ case TARGET_F_SETOWN_EX:
+ ret = F_SETOWN_EX;
+ break;
#endif
#ifdef F_SETPIPE_SZ
- case TARGET_F_SETPIPE_SZ:
- return F_SETPIPE_SZ;
- case TARGET_F_GETPIPE_SZ:
- return F_GETPIPE_SZ;
+ case TARGET_F_SETPIPE_SZ:
+ ret = F_SETPIPE_SZ;
+ break;
+ case TARGET_F_GETPIPE_SZ:
+ ret = F_GETPIPE_SZ;
+ break;
#endif
- default:
- return -TARGET_EINVAL;
+ default:
+ ret = -TARGET_EINVAL;
+ break;
}
- return -TARGET_EINVAL;
+
+#if defined(__powerpc64__)
+ /* On PPC64, glibc headers has the F_*LK* defined to 12, 13 and 14 and
+ * is not supported by kernel. The glibc fcntl call actually adjusts
+ * them to 5, 6 and 7 before making the syscall(). Since we make the
+ * syscall directly, adjust to what is supported by the kernel.
+ */
+ if (ret >= F_GETLK64 && ret <= F_SETLKW64) {
+ ret -= F_GETLK64 - 5;
+ }
+#endif
+
+ return ret;
}
#define TRANSTBL_CONVERT(a) { -1, TARGET_##a, -1, a }
Le 13/07/2018 à 14:34, Shivaprasad G Bhat a écrit : > Qemu includes the glibc headers for the host defines and target headers are > part of the qemu source themselves. The glibc has the F_GETLK64, F_SETLK64 > and F_SETLKW64 defined to 12, 13 and 14 for all archs in > sysdeps/unix/sysv/linux/bits/fcntl-linux.h. The linux kernel generic > definition for F_*LK is 5, 6 & 7 and F_*LK64* is 12,13, and 14 as seen in > include/uapi/asm-generic/fcntl.h. On 64bit machine, by default the kernel > assumes all F_*LK to 64bit calls and doesnt support use of F_*LK64* as > can be seen in include/linux/fcntl.h in linux source. > > On x86_64 host, the values for F_*LK64* are set to 5, 6 and 7 > explicitly in /usr/include/x86_64-linux-gnu/bits/fcntl.h by the glibc. > Whereas, a PPC64 host doesn't have such a definition in > /usr/include/powerpc64le-linux-gnu/bits/fcntl.h by the glibc. So, > the sources on PPC64 host sees the default value of F_*LK64* > as 12, 13 & 14(fcntl-linux.h). > > Since the 64bit kernel doesnt support 12, 13 & 14; the glibc fcntl syscall > implementation(__libc_fcntl*(), __fcntl64_nocancel) does the F_*LK64* value > convertion back to F_*LK* values on PPC64 as seen in > sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h with FCNTL_ADJUST_CMD() > macro. Whereas on x86_64 host the values for F_*LK64* are set to 5, 6 and 7 > and no adjustments are needed. > > Since qemu doesnt use the glibc fcntl, but makes the safe_syscall* on its > own, the PPC64 qemu is calling the syscall with 12, 13, and 14(without > adjustment) and they all fail. The fcntl calls to F_GETLK/F_SETLK|W all > fail by all pplications run on PPC64 host user emulation. > > The fix here could be to see why on PPC64 the glibc is still keeping > F_*LK64* different from F_*LK and why adjusting them to 5, 6 and 7 before > the syscall for PPC only. See if we can make the > /usr/include/powerpc64le-linux-gnu/bits/fcntl.h to have the values > 5, 6 & 7 just like x86_64 and remove the adjustment code in glibc. That > way, qemu sources see the kernel supported values in glibc headers. > > OR > > On PPC64 host, qemu sources see both F_*LK & F_*LK64* as same and set to > 12, 13 and 14 because __USE_FILE_OFFSET64 is defined in qemu > sources(also refer sysdeps/unix/sysv/linux/bits/fcntl-linux.h). > Do the value adjustment just like it is done by glibc source by using > F_GETLK value of 5. That way, we make the syscalls with the actual > supported values in Qemu. The patch is taking this approach. > > Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> > --- > v3 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02923.html > Changes from v3: > - Fixed the tabs for case statements > - Addressed the comments on v3 wrt to the variable initialisation > and break from default case. > v2 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02920.html > Changes from v2: > - Fixed the braces, and indentation for comments. > v1 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02567.html > Changes from v1: > - Changed the overwrite of F*LK64* with 5, 6 and 7 in using #define > instead using the adjustment code similar to glibc as suggested. > - Dropped __linux__ check for the adjustment code as suggested. > - Moved the adjustment code inside target_to_host_fcntl_cmd to address > all possible|future cases. > > linux-user/syscall.c | 126 ++++++++++++++++++++++++++++++++------------------ > 1 file changed, 80 insertions(+), 46 deletions(-) > Reviewed-by: Laurent Vivier <laurent@vivier.eu>
On Fri, Jul 13, 2018 at 07:34:46AM -0500, Shivaprasad G Bhat wrote: > Qemu includes the glibc headers for the host defines and target headers are > part of the qemu source themselves. The glibc has the F_GETLK64, F_SETLK64 > and F_SETLKW64 defined to 12, 13 and 14 for all archs in > sysdeps/unix/sysv/linux/bits/fcntl-linux.h. The linux kernel generic > definition for F_*LK is 5, 6 & 7 and F_*LK64* is 12,13, and 14 as seen in > include/uapi/asm-generic/fcntl.h. On 64bit machine, by default the kernel > assumes all F_*LK to 64bit calls and doesnt support use of F_*LK64* as > can be seen in include/linux/fcntl.h in linux source. > > On x86_64 host, the values for F_*LK64* are set to 5, 6 and 7 > explicitly in /usr/include/x86_64-linux-gnu/bits/fcntl.h by the glibc. > Whereas, a PPC64 host doesn't have such a definition in > /usr/include/powerpc64le-linux-gnu/bits/fcntl.h by the glibc. So, > the sources on PPC64 host sees the default value of F_*LK64* > as 12, 13 & 14(fcntl-linux.h). > > Since the 64bit kernel doesnt support 12, 13 & 14; the glibc fcntl syscall > implementation(__libc_fcntl*(), __fcntl64_nocancel) does the F_*LK64* value > convertion back to F_*LK* values on PPC64 as seen in > sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h with FCNTL_ADJUST_CMD() > macro. Whereas on x86_64 host the values for F_*LK64* are set to 5, 6 and 7 > and no adjustments are needed. > > Since qemu doesnt use the glibc fcntl, but makes the safe_syscall* on its > own, the PPC64 qemu is calling the syscall with 12, 13, and 14(without > adjustment) and they all fail. The fcntl calls to F_GETLK/F_SETLK|W all > fail by all pplications run on PPC64 host user emulation. > > The fix here could be to see why on PPC64 the glibc is still keeping > F_*LK64* different from F_*LK and why adjusting them to 5, 6 and 7 before > the syscall for PPC only. See if we can make the > /usr/include/powerpc64le-linux-gnu/bits/fcntl.h to have the values > 5, 6 & 7 just like x86_64 and remove the adjustment code in glibc. That > way, qemu sources see the kernel supported values in glibc headers. > > OR > > On PPC64 host, qemu sources see both F_*LK & F_*LK64* as same and set to > 12, 13 and 14 because __USE_FILE_OFFSET64 is defined in qemu > sources(also refer sysdeps/unix/sysv/linux/bits/fcntl-linux.h). > Do the value adjustment just like it is done by glibc source by using > F_GETLK value of 5. That way, we make the syscalls with the actual > supported values in Qemu. The patch is taking this approach. > > Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> I'm not sure if this should go in through my tree or not. > --- > v3 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02923.html > Changes from v3: > - Fixed the tabs for case statements > - Addressed the comments on v3 wrt to the variable initialisation > and break from default case. > v2 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02920.html > Changes from v2: > - Fixed the braces, and indentation for comments. > v1 - https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg02567.html > Changes from v1: > - Changed the overwrite of F*LK64* with 5, 6 and 7 in using #define > instead using the adjustment code similar to glibc as suggested. > - Dropped __linux__ check for the adjustment code as suggested. > - Moved the adjustment code inside target_to_host_fcntl_cmd to address > all possible|future cases. > > linux-user/syscall.c | 126 ++++++++++++++++++++++++++++++++------------------ > 1 file changed, 80 insertions(+), 46 deletions(-) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 643b8833de..b5274f657a 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -6475,63 +6475,97 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, > /* warning : doesn't handle linux specific flags... */ > static int target_to_host_fcntl_cmd(int cmd) > { > + int ret; > + > switch(cmd) { > - case TARGET_F_DUPFD: > - case TARGET_F_GETFD: > - case TARGET_F_SETFD: > - case TARGET_F_GETFL: > - case TARGET_F_SETFL: > - return cmd; > - case TARGET_F_GETLK: > - return F_GETLK64; > - case TARGET_F_SETLK: > - return F_SETLK64; > - case TARGET_F_SETLKW: > - return F_SETLKW64; > - case TARGET_F_GETOWN: > - return F_GETOWN; > - case TARGET_F_SETOWN: > - return F_SETOWN; > - case TARGET_F_GETSIG: > - return F_GETSIG; > - case TARGET_F_SETSIG: > - return F_SETSIG; > + case TARGET_F_DUPFD: > + case TARGET_F_GETFD: > + case TARGET_F_SETFD: > + case TARGET_F_GETFL: > + case TARGET_F_SETFL: > + ret = cmd; > + break; > + case TARGET_F_GETLK: > + ret = F_GETLK64; > + break; > + case TARGET_F_SETLK: > + ret = F_SETLK64; > + break; > + case TARGET_F_SETLKW: > + ret = F_SETLKW64; > + break; > + case TARGET_F_GETOWN: > + ret = F_GETOWN; > + break; > + case TARGET_F_SETOWN: > + ret = F_SETOWN; > + break; > + case TARGET_F_GETSIG: > + ret = F_GETSIG; > + break; > + case TARGET_F_SETSIG: > + ret = F_SETSIG; > + break; > #if TARGET_ABI_BITS == 32 > - case TARGET_F_GETLK64: > - return F_GETLK64; > - case TARGET_F_SETLK64: > - return F_SETLK64; > - case TARGET_F_SETLKW64: > - return F_SETLKW64; > -#endif > - case TARGET_F_SETLEASE: > - return F_SETLEASE; > - case TARGET_F_GETLEASE: > - return F_GETLEASE; > + case TARGET_F_GETLK64: > + ret = F_GETLK64; > + break; > + case TARGET_F_SETLK64: > + ret = F_SETLK64; > + break; > + case TARGET_F_SETLKW64: > + ret = F_SETLKW64; > + break; > +#endif > + case TARGET_F_SETLEASE: > + ret = F_SETLEASE; > + break; > + case TARGET_F_GETLEASE: > + ret = F_GETLEASE; > + break; > #ifdef F_DUPFD_CLOEXEC > - case TARGET_F_DUPFD_CLOEXEC: > - return F_DUPFD_CLOEXEC; > + case TARGET_F_DUPFD_CLOEXEC: > + ret = F_DUPFD_CLOEXEC; > + break; > #endif > - case TARGET_F_NOTIFY: > - return F_NOTIFY; > + case TARGET_F_NOTIFY: > + ret = F_NOTIFY; > + break; > #ifdef F_GETOWN_EX > - case TARGET_F_GETOWN_EX: > - return F_GETOWN_EX; > + case TARGET_F_GETOWN_EX: > + ret = F_GETOWN_EX; > + break; > #endif > #ifdef F_SETOWN_EX > - case TARGET_F_SETOWN_EX: > - return F_SETOWN_EX; > + case TARGET_F_SETOWN_EX: > + ret = F_SETOWN_EX; > + break; > #endif > #ifdef F_SETPIPE_SZ > - case TARGET_F_SETPIPE_SZ: > - return F_SETPIPE_SZ; > - case TARGET_F_GETPIPE_SZ: > - return F_GETPIPE_SZ; > + case TARGET_F_SETPIPE_SZ: > + ret = F_SETPIPE_SZ; > + break; > + case TARGET_F_GETPIPE_SZ: > + ret = F_GETPIPE_SZ; > + break; > #endif > - default: > - return -TARGET_EINVAL; > + default: > + ret = -TARGET_EINVAL; > + break; > } > - return -TARGET_EINVAL; > + > +#if defined(__powerpc64__) > + /* On PPC64, glibc headers has the F_*LK* defined to 12, 13 and 14 and > + * is not supported by kernel. The glibc fcntl call actually adjusts > + * them to 5, 6 and 7 before making the syscall(). Since we make the > + * syscall directly, adjust to what is supported by the kernel. > + */ > + if (ret >= F_GETLK64 && ret <= F_SETLKW64) { > + ret -= F_GETLK64 - 5; > + } > +#endif > + > + return ret; > } > > #define TRANSTBL_CONVERT(a) { -1, TARGET_##a, -1, a } > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
Le 14/07/2018 à 03:07, David Gibson a écrit : > On Fri, Jul 13, 2018 at 07:34:46AM -0500, Shivaprasad G Bhat wrote: >> Qemu includes the glibc headers for the host defines and target headers are >> part of the qemu source themselves. The glibc has the F_GETLK64, F_SETLK64 >> and F_SETLKW64 defined to 12, 13 and 14 for all archs in >> sysdeps/unix/sysv/linux/bits/fcntl-linux.h. The linux kernel generic >> definition for F_*LK is 5, 6 & 7 and F_*LK64* is 12,13, and 14 as seen in >> include/uapi/asm-generic/fcntl.h. On 64bit machine, by default the kernel >> assumes all F_*LK to 64bit calls and doesnt support use of F_*LK64* as >> can be seen in include/linux/fcntl.h in linux source. >> >> On x86_64 host, the values for F_*LK64* are set to 5, 6 and 7 >> explicitly in /usr/include/x86_64-linux-gnu/bits/fcntl.h by the glibc. >> Whereas, a PPC64 host doesn't have such a definition in >> /usr/include/powerpc64le-linux-gnu/bits/fcntl.h by the glibc. So, >> the sources on PPC64 host sees the default value of F_*LK64* >> as 12, 13 & 14(fcntl-linux.h). >> >> Since the 64bit kernel doesnt support 12, 13 & 14; the glibc fcntl syscall >> implementation(__libc_fcntl*(), __fcntl64_nocancel) does the F_*LK64* value >> convertion back to F_*LK* values on PPC64 as seen in >> sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h with FCNTL_ADJUST_CMD() >> macro. Whereas on x86_64 host the values for F_*LK64* are set to 5, 6 and 7 >> and no adjustments are needed. >> >> Since qemu doesnt use the glibc fcntl, but makes the safe_syscall* on its >> own, the PPC64 qemu is calling the syscall with 12, 13, and 14(without >> adjustment) and they all fail. The fcntl calls to F_GETLK/F_SETLK|W all >> fail by all pplications run on PPC64 host user emulation. >> >> The fix here could be to see why on PPC64 the glibc is still keeping >> F_*LK64* different from F_*LK and why adjusting them to 5, 6 and 7 before >> the syscall for PPC only. See if we can make the >> /usr/include/powerpc64le-linux-gnu/bits/fcntl.h to have the values >> 5, 6 & 7 just like x86_64 and remove the adjustment code in glibc. That >> way, qemu sources see the kernel supported values in glibc headers. >> >> OR >> >> On PPC64 host, qemu sources see both F_*LK & F_*LK64* as same and set to >> 12, 13 and 14 because __USE_FILE_OFFSET64 is defined in qemu >> sources(also refer sysdeps/unix/sysv/linux/bits/fcntl-linux.h). >> Do the value adjustment just like it is done by glibc source by using >> F_GETLK value of 5. That way, we make the syscalls with the actual >> supported values in Qemu. The patch is taking this approach. >> >> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> > > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > I'm not sure if this should go in through my tree or not. I will take it through my linux-user tree, I have some fixes to send for the next -rc. Thanks, Laurent
On Sat, Jul 14, 2018 at 07:37:43AM +0200, Laurent Vivier wrote: > Le 14/07/2018 à 03:07, David Gibson a écrit : > > On Fri, Jul 13, 2018 at 07:34:46AM -0500, Shivaprasad G Bhat wrote: > >> Qemu includes the glibc headers for the host defines and target headers are > >> part of the qemu source themselves. The glibc has the F_GETLK64, F_SETLK64 > >> and F_SETLKW64 defined to 12, 13 and 14 for all archs in > >> sysdeps/unix/sysv/linux/bits/fcntl-linux.h. The linux kernel generic > >> definition for F_*LK is 5, 6 & 7 and F_*LK64* is 12,13, and 14 as seen in > >> include/uapi/asm-generic/fcntl.h. On 64bit machine, by default the kernel > >> assumes all F_*LK to 64bit calls and doesnt support use of F_*LK64* as > >> can be seen in include/linux/fcntl.h in linux source. > >> > >> On x86_64 host, the values for F_*LK64* are set to 5, 6 and 7 > >> explicitly in /usr/include/x86_64-linux-gnu/bits/fcntl.h by the glibc. > >> Whereas, a PPC64 host doesn't have such a definition in > >> /usr/include/powerpc64le-linux-gnu/bits/fcntl.h by the glibc. So, > >> the sources on PPC64 host sees the default value of F_*LK64* > >> as 12, 13 & 14(fcntl-linux.h). > >> > >> Since the 64bit kernel doesnt support 12, 13 & 14; the glibc fcntl syscall > >> implementation(__libc_fcntl*(), __fcntl64_nocancel) does the F_*LK64* value > >> convertion back to F_*LK* values on PPC64 as seen in > >> sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h with FCNTL_ADJUST_CMD() > >> macro. Whereas on x86_64 host the values for F_*LK64* are set to 5, 6 and 7 > >> and no adjustments are needed. > >> > >> Since qemu doesnt use the glibc fcntl, but makes the safe_syscall* on its > >> own, the PPC64 qemu is calling the syscall with 12, 13, and 14(without > >> adjustment) and they all fail. The fcntl calls to F_GETLK/F_SETLK|W all > >> fail by all pplications run on PPC64 host user emulation. > >> > >> The fix here could be to see why on PPC64 the glibc is still keeping > >> F_*LK64* different from F_*LK and why adjusting them to 5, 6 and 7 before > >> the syscall for PPC only. See if we can make the > >> /usr/include/powerpc64le-linux-gnu/bits/fcntl.h to have the values > >> 5, 6 & 7 just like x86_64 and remove the adjustment code in glibc. That > >> way, qemu sources see the kernel supported values in glibc headers. > >> > >> OR > >> > >> On PPC64 host, qemu sources see both F_*LK & F_*LK64* as same and set to > >> 12, 13 and 14 because __USE_FILE_OFFSET64 is defined in qemu > >> sources(also refer sysdeps/unix/sysv/linux/bits/fcntl-linux.h). > >> Do the value adjustment just like it is done by glibc source by using > >> F_GETLK value of 5. That way, we make the syscalls with the actual > >> supported values in Qemu. The patch is taking this approach. > >> > >> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> > > > > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > > > I'm not sure if this should go in through my tree or not. > > I will take it through my linux-user tree, I have some fixes to send for > the next -rc. Great, thanks. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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