On Wed, 3 Feb 2021 at 19:00, Richard Henderson
<richard.hender...@linaro.org> wrote:
>
> Resolve the untagged address once, using thread_cpu.
> Tidy the DEBUG_REMAP code using glib routines.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> linux-user/uaccess.c | 29 +++++++++++++++--------------
> 1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c
> index 30d01f8b30..c696913016 100644
> --- a/linux-user/uaccess.c
> +++ b/linux-user/uaccess.c
> @@ -6,36 +6,37 @@
>
> void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy)
> {
> + void *host_addr;
> +
> + guest_addr = cpu_untagged_addr(thread_cpu, guest_addr);
> if (!access_ok_untagged(type, guest_addr, len)) {
> return NULL;
> }
> + host_addr = g2h_untagged(guest_addr);
> #ifdef DEBUG_REMAP
> - {
> - void *addr;
> - addr = g_malloc(len);
> - if (copy) {
> - memcpy(addr, g2h(guest_addr), len);
> - } else {
> - memset(addr, 0, len);
> - }
> - return addr;
> + if (copy) {
> + host_addr = g_memdup(host_addr, len);
> + } else {
> + host_addr = g_malloc0(len);
> }
> -#else
> - return g2h_untagged(guest_addr);
> #endif
> + return host_addr;
> }
>
> #ifdef DEBUG_REMAP
> void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len);
> {
> + void *host_ptr_conv;
> +
> if (!host_ptr) {
> return;
> }
> - if (host_ptr == g2h_untagged(guest_addr)) {
> + host_ptr_conv = g2h(thread_cpu, guest_addr);
> + if (host_ptr == host_ptr_conv) {
> return;
> }
> - if (len > 0) {
> - memcpy(g2h_untagged(guest_addr), host_ptr, len);
> + if (len != 0) {
> + memcpy(host_ptr_conv, host_ptr, len);
> }
Why the change from checking >0 to checking !=0 ? I'd rather not
have to go through and audit all the callsites to confirm none
of them pass a "length-or-negative-errno" value here...
thanks
-- PMM
