linux-user/syscall.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)
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);
--
2.11.0
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~
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. -- Thanks. -- Max
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 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. -- Thanks. -- Max
© 2016 - 2024 Red Hat, Inc.