From 347ec03093f9668a379ef6b7fa1feb332fff039c Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Fri, 12 May 2017 12:05:23 -0700
Subject: [PATCH] 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: Max Filippov <jcmvbkbc@gmail.com>
---
target/xtensa/xtensa-semi.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/target/xtensa/xtensa-semi.c b/target/xtensa/xtensa-semi.c
index 98ae28ce71..ffcaf8d0ac 100644
--- a/target/xtensa/xtensa-semi.c
+++ b/target/xtensa/xtensa-semi.c
@@ -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;
--
2.30.2