Commit 347ec030 authored by Max Filippov's avatar Max Filippov
Browse files

target/xtensa: fix return value of read/write simcalls 



Return value of read/write simcalls is not calculated correctly in case
of operations crossing page boundary and in case of short reads/writes.
Read and write simcalls should return the size of data actually
read/written or -1 in case of error.

Cc: qemu-stable@nongnu.org
Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 30c2afd1

target/xtensa/xtensa-semi.c

+20 −5
Original line number Diff line number Diff line
@@ -166,6 +166,7 @@ void HELPER(simcall)(CPUXtensaState *env) 
            uint32_t fd = regs[3];

            uint32_t vaddr = regs[4];

            uint32_t len = regs[5];

            uint32_t len_done = 0;



            while (len > 0) {

                hwaddr paddr = cpu_get_phys_page_debug(cs, vaddr);
@@ -174,24 +175,38 @@ void HELPER(simcall)(CPUXtensaState *env) 
                uint32_t io_sz = page_left < len ? page_left : len;

                hwaddr sz = io_sz;

                void *buf = cpu_physical_memory_map(paddr, &sz, !is_write);

                uint32_t io_done;

                bool error = false;



                if (buf) {

                    vaddr += io_sz;

                    len -= io_sz;

                    regs[2] = is_write ?

                    io_done = is_write ?

                        write(fd, buf, io_sz) :

                        read(fd, buf, io_sz);

                    regs[3] = errno_h2g(errno);

                    cpu_physical_memory_unmap(buf, sz, !is_write, sz);

                    if (regs[2] == -1) {

                        break;

                    if (io_done == -1) {

                        error = true;

                        io_done = 0;

                    }

                    cpu_physical_memory_unmap(buf, sz, !is_write, io_done);

                } else {

                    regs[2] = -1;

                    error = true;

                    regs[3] = TARGET_EINVAL;

                    break;

                }

                if (error) {

                    if (!len_done) {

                        len_done = -1;

                    }

                    break;

                }

                len_done += io_done;

                if (io_done < io_sz) {

                    break;

                }

            }

            regs[2] = len_done;

        }

        break;