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[Qemu-devel] [PULL 1/1] linux-user: fix preadv/pwritev offsets
From: |
Max Filippov |
Subject: |
[Qemu-devel] [PULL 1/1] linux-user: fix preadv/pwritev offsets |
Date: |
Mon, 9 Apr 2018 19:17:45 -0700 |
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_to_host_low_high that does this recombination and use
it in preadv/pwritev syscalls.
This fixes glibc testsuite test misc/tst-preadvwritev64.
Reviewed-by: Laurent Vivier <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Signed-off-by: Max Filippov <address@hidden>
---
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..0eab5cc6ade1 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;
}
+/* Convert target low/high pair representing file offset into the host
+ * low/high pair. This function doesn't handle offsets bigger than 64 bits
+ * as the kernel doesn't handle them either.
+ */
+static void target_to_host_low_high(abi_ulong tlow,
+ abi_ulong thigh,
+ unsigned long *hlow,
+ unsigned long *hhigh)
+{
+ uint64_t off = tlow |
+ ((unsigned long long)thigh << TARGET_LONG_BITS / 2) <<
+ TARGET_LONG_BITS / 2;
+
+ *hlow = off;
+ *hhigh = (off >> HOST_LONG_BITS / 2) >> HOST_LONG_BITS / 2;
+}
+
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_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_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