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 <sb...@linux.vnet.ibm.com>
Reviewed-by: David Gibson <da...@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
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