| Message ID | 20180405014135.3235-1-jcmvbkbc@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/05/2018 11:41 AM, Max Filippov wrote: > +static void target_low_high_to_host_low_high(abi_ulong tlow, > + abi_ulong thigh, > + unsigned long *hlow, > + unsigned long *hhigh) > +{ > +#if TARGET_LONG_BITS == HOST_LONG_BITS > + *hlow = tlow; > + *hhigh = thigh; > +#elif TARGET_LONG_BITS < HOST_LONG_BITS > + *hlow = tlow | (unsigned long)thigh << TARGET_LONG_BITS; > + *hhigh = 0; > +#else > + *hlow = (unsigned long)tlow; > + *hhigh = (unsigned long)(tlow >> HOST_LONG_BITS); > +#endif It might still be worth a check for HOST_LONG_BITS >= 2 * TARGET_LONG_BITS and #error otherwise. Or explicit checks vs 32 & 64 if you like. r~
Le 05/04/2018 à 03:41, Max Filippov a écrit : > preadv/pwritev accept low and high parts of file offset in two separate > parameters. When host bitness doesn't match guest bitness these parts > must be appropriately recombined. > Introduce target_low_high_to_host_low_high that does this recombination > and use it in preadv/pwritev syscalls. > > This fixes glibc testsuite test misc/tst-preadvwritev64. > > Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> > --- > Changes v1->v2: > - fix host high computation in TARGET_LONG_BITS > HOST_LONG_BITS case > > linux-user/syscall.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 5ef517613577..7e014066260a 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -3386,6 +3386,23 @@ static abi_long do_getsockopt(int sockfd, int level, int optname, > return ret; > } > > +static void target_low_high_to_host_low_high(abi_ulong tlow, > + abi_ulong thigh, > + unsigned long *hlow, > + unsigned long *hhigh) > +{ > +#if TARGET_LONG_BITS == HOST_LONG_BITS > + *hlow = tlow; > + *hhigh = thigh; > +#elif TARGET_LONG_BITS < HOST_LONG_BITS > + *hlow = tlow | (unsigned long)thigh << TARGET_LONG_BITS; > + *hhigh = 0; > +#else > + *hlow = (unsigned long)tlow; > + *hhigh = (unsigned long)(tlow >> HOST_LONG_BITS); > +#endif > +} > + > static struct iovec *lock_iovec(int type, abi_ulong target_addr, > abi_ulong count, int copy) > { > @@ -10449,7 +10466,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > { > struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0); > if (vec != NULL) { > - ret = get_errno(safe_preadv(arg1, vec, arg3, arg4, arg5)); > + unsigned long low, high; > + > + target_low_high_to_host_low_high(arg4, arg5, &low, &high); > + ret = get_errno(safe_preadv(arg1, vec, arg3, low, high)); > unlock_iovec(vec, arg2, arg3, 1); > } else { > ret = -host_to_target_errno(errno); > @@ -10462,7 +10482,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, > { > struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1); > if (vec != NULL) { > - ret = get_errno(safe_pwritev(arg1, vec, arg3, arg4, arg5)); > + unsigned long low, high; > + > + target_low_high_to_host_low_high(arg4, arg5, &low, &high); > + ret = get_errno(safe_pwritev(arg1, vec, arg3, low, high)); > unlock_iovec(vec, arg2, arg3, 0); > } else { > ret = -host_to_target_errno(errno); > Did you try to use the regpairs_aligned() and target_offset64() functions as it is done for pread64(), pwrite64(), fadvise64(),... ? Thanks, Laurent
On Wed, Apr 4, 2018 at 8:43 PM, Richard Henderson <richard.henderson@linaro.org> wrote: > On 04/05/2018 11:41 AM, Max Filippov wrote: >> +static void target_low_high_to_host_low_high(abi_ulong tlow, >> + abi_ulong thigh, >> + unsigned long *hlow, >> + unsigned long *hhigh) >> +{ >> +#if TARGET_LONG_BITS == HOST_LONG_BITS >> + *hlow = tlow; >> + *hhigh = thigh; >> +#elif TARGET_LONG_BITS < HOST_LONG_BITS >> + *hlow = tlow | (unsigned long)thigh << TARGET_LONG_BITS; >> + *hhigh = 0; >> +#else >> + *hlow = (unsigned long)tlow; >> + *hhigh = (unsigned long)(tlow >> HOST_LONG_BITS); >> +#endif > > It might still be worth a check for HOST_LONG_BITS >= 2 * TARGET_LONG_BITS and > #error otherwise. Or explicit checks vs 32 & 64 if you like. Ok, will do in v3.
On Thu, Apr 5, 2018 at 2:03 AM, Laurent Vivier <laurent@vivier.eu> wrote: > Did you try to use the regpairs_aligned() and target_offset64() > functions as it is done for pread64(), pwrite64(), fadvise64(),... ? My understanding is that if the syscalls had single parameter that took two registers then it'd be a place to use regpairs_aligned. By the syscalls are defined as follows: SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) so these are normal unsigned long arguments, low part, then the high part. target_offset64 treats arguments differently depending on the target endianness, which is not needed for preadv/pwritev.
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 5ef517613577..7e014066260a 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -3386,6 +3386,23 @@ static abi_long do_getsockopt(int sockfd, int level, int optname, return ret; } +static void target_low_high_to_host_low_high(abi_ulong tlow, + abi_ulong thigh, + unsigned long *hlow, + unsigned long *hhigh) +{ +#if TARGET_LONG_BITS == HOST_LONG_BITS + *hlow = tlow; + *hhigh = thigh; +#elif TARGET_LONG_BITS < HOST_LONG_BITS + *hlow = tlow | (unsigned long)thigh << TARGET_LONG_BITS; + *hhigh = 0; +#else + *hlow = (unsigned long)tlow; + *hhigh = (unsigned long)(tlow >> HOST_LONG_BITS); +#endif +} + static struct iovec *lock_iovec(int type, abi_ulong target_addr, abi_ulong count, int copy) { @@ -10449,7 +10466,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, { struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0); if (vec != NULL) { - ret = get_errno(safe_preadv(arg1, vec, arg3, arg4, arg5)); + unsigned long low, high; + + target_low_high_to_host_low_high(arg4, arg5, &low, &high); + ret = get_errno(safe_preadv(arg1, vec, arg3, low, high)); unlock_iovec(vec, arg2, arg3, 1); } else { ret = -host_to_target_errno(errno); @@ -10462,7 +10482,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, { struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1); if (vec != NULL) { - ret = get_errno(safe_pwritev(arg1, vec, arg3, arg4, arg5)); + unsigned long low, high; + + target_low_high_to_host_low_high(arg4, arg5, &low, &high); + ret = get_errno(safe_pwritev(arg1, vec, arg3, low, high)); unlock_iovec(vec, arg2, arg3, 0); } else { ret = -host_to_target_errno(errno);
preadv/pwritev accept low and high parts of file offset in two separate parameters. When host bitness doesn't match guest bitness these parts must be appropriately recombined. Introduce target_low_high_to_host_low_high that does this recombination and use it in preadv/pwritev syscalls. This fixes glibc testsuite test misc/tst-preadvwritev64. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> --- Changes v1->v2: - fix host high computation in TARGET_LONG_BITS > HOST_LONG_BITS case linux-user/syscall.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)