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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2018-01-09 21:16:43 +0100
committerLaurent Vivier <laurent@vivier.eu>2018-01-23 14:20:52 +0100
commit2e0a8713bd6804ce49044915ba9cd5bd7148de77 (patch)
treefa9f232f2cd1017d520518e52ed318cc3de8ceb0
parent95e6d4305affbbf5258c6a533be9bfd24599da90 (diff)
linux-user: Fix sched_get/setaffinity conversion
sched_get/setaffinity linux-user syscalls were missing conversions for little/big endian, which is hairy since longs may not be the same size either. For simplicity, this just introduces loops to convert bit by bit like is done for select. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20180109201643.1479-1-samuel.thibault@ens-lyon.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
-rw-r--r--linux-user/syscall.c81
1 files changed, 73 insertions, 8 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 41ded90ee6..143e4a959d 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -7731,6 +7731,73 @@ static TargetFdTrans target_inotify_trans = {
};
#endif
+static int target_to_host_cpu_mask(unsigned long *host_mask,
+ size_t host_size,
+ abi_ulong target_addr,
+ size_t target_size)
+{
+ unsigned target_bits = sizeof(abi_ulong) * 8;
+ unsigned host_bits = sizeof(*host_mask) * 8;
+ abi_ulong *target_mask;
+ unsigned i, j;
+
+ assert(host_size >= target_size);
+
+ target_mask = lock_user(VERIFY_READ, target_addr, target_size, 1);
+ if (!target_mask) {
+ return -TARGET_EFAULT;
+ }
+ memset(host_mask, 0, host_size);
+
+ for (i = 0 ; i < target_size / sizeof(abi_ulong); i++) {
+ unsigned bit = i * target_bits;
+ abi_ulong val;
+
+ __get_user(val, &target_mask[i]);
+ for (j = 0; j < target_bits; j++, bit++) {
+ if (val & (1UL << j)) {
+ host_mask[bit / host_bits] |= 1UL << (bit % host_bits);
+ }
+ }
+ }
+
+ unlock_user(target_mask, target_addr, 0);
+ return 0;
+}
+
+static int host_to_target_cpu_mask(const unsigned long *host_mask,
+ size_t host_size,
+ abi_ulong target_addr,
+ size_t target_size)
+{
+ unsigned target_bits = sizeof(abi_ulong) * 8;
+ unsigned host_bits = sizeof(*host_mask) * 8;
+ abi_ulong *target_mask;
+ unsigned i, j;
+
+ assert(host_size >= target_size);
+
+ target_mask = lock_user(VERIFY_WRITE, target_addr, target_size, 0);
+ if (!target_mask) {
+ return -TARGET_EFAULT;
+ }
+
+ for (i = 0 ; i < target_size / sizeof(abi_ulong); i++) {
+ unsigned bit = i * target_bits;
+ abi_ulong val = 0;
+
+ for (j = 0; j < target_bits; j++, bit++) {
+ if (host_mask[bit / host_bits] & (1UL << (bit % host_bits))) {
+ val |= 1UL << j;
+ }
+ }
+ __put_user(val, &target_mask[i]);
+ }
+
+ unlock_user(target_mask, target_addr, target_size);
+ return 0;
+}
+
/* do_syscall() should always have a single exit point at the end so
that actions, such as logging of syscall results, can be performed.
All errnos that do_syscall() returns must be -TARGET_<errcode>. */
@@ -10376,6 +10443,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
mask = alloca(mask_size);
+ memset(mask, 0, mask_size);
ret = get_errno(sys_sched_getaffinity(arg1, mask_size, mask));
if (!is_error(ret)) {
@@ -10395,9 +10463,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
ret = arg2;
}
- if (copy_to_user(arg3, mask, ret)) {
- goto efault;
- }
+ ret = host_to_target_cpu_mask(mask, mask_size, arg3, arg2);
}
}
break;
@@ -10415,13 +10481,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
break;
}
mask_size = (arg2 + (sizeof(*mask) - 1)) & ~(sizeof(*mask) - 1);
-
mask = alloca(mask_size);
- if (!lock_user_struct(VERIFY_READ, p, arg3, 1)) {
- goto efault;
+
+ ret = target_to_host_cpu_mask(mask, mask_size, arg3, arg2);
+ if (ret) {
+ break;
}
- memcpy(mask, p, arg2);
- unlock_user_struct(p, arg2, 0);
ret = get_errno(sys_sched_setaffinity(arg1, mask_size, mask));
}