cpu_ioreq_pio, cpu_ioreq_move: introduce read_phys_req_item, write_phys_req_item
Replace a lot of formulaic multiplications (containing casts, no less) with calls to a pair of functions. This encapsulates in a single place the operations which require care relating to integer overflow. Cc: Dongxiao Xu <dongxiao.xu@intel.com> Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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parent
f1b8caf1d9
commit
a38648290e
76
xen-all.c
76
xen-all.c
@ -683,11 +683,45 @@ static void do_outp(pio_addr_t addr,
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}
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}
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/*
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* Helper functions which read/write an object from/to physical guest
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* memory, as part of the implementation of an ioreq.
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*
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* Equivalent to
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* cpu_physical_memory_rw(addr + (req->df ? -1 : +1) * req->size * i,
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* val, req->size, 0/1)
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* except without the integer overflow problems.
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*/
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static void rw_phys_req_item(hwaddr addr,
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ioreq_t *req, uint32_t i, void *val, int rw)
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{
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/* Do everything unsigned so overflow just results in a truncated result
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* and accesses to undesired parts of guest memory, which is up
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* to the guest */
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hwaddr offset = (hwaddr)req->size * i;
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if (req->df) {
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addr -= offset;
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} else {
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addr += offset;
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}
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cpu_physical_memory_rw(addr, val, req->size, rw);
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}
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static inline void read_phys_req_item(hwaddr addr,
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ioreq_t *req, uint32_t i, void *val)
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{
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rw_phys_req_item(addr, req, i, val, 0);
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}
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static inline void write_phys_req_item(hwaddr addr,
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ioreq_t *req, uint32_t i, void *val)
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{
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rw_phys_req_item(addr, req, i, val, 1);
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}
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static void cpu_ioreq_pio(ioreq_t *req)
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{
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int i, sign;
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sign = req->df ? -1 : 1;
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int i;
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if (req->dir == IOREQ_READ) {
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if (!req->data_is_ptr) {
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@ -697,9 +731,7 @@ static void cpu_ioreq_pio(ioreq_t *req)
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for (i = 0; i < req->count; i++) {
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tmp = do_inp(req->addr, req->size);
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cpu_physical_memory_write(
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req->data + (sign * i * (int64_t)req->size),
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(uint8_t *) &tmp, req->size);
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write_phys_req_item(req->data, req, i, &tmp);
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}
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}
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} else if (req->dir == IOREQ_WRITE) {
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@ -709,9 +741,7 @@ static void cpu_ioreq_pio(ioreq_t *req)
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for (i = 0; i < req->count; i++) {
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uint32_t tmp = 0;
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cpu_physical_memory_read(
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req->data + (sign * i * (int64_t)req->size),
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(uint8_t*) &tmp, req->size);
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read_phys_req_item(req->data, req, i, &tmp);
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do_outp(req->addr, req->size, tmp);
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}
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}
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@ -720,22 +750,16 @@ static void cpu_ioreq_pio(ioreq_t *req)
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static void cpu_ioreq_move(ioreq_t *req)
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{
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int i, sign;
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sign = req->df ? -1 : 1;
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int i;
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if (!req->data_is_ptr) {
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if (req->dir == IOREQ_READ) {
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for (i = 0; i < req->count; i++) {
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cpu_physical_memory_read(
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req->addr + (sign * i * (int64_t)req->size),
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(uint8_t *) &req->data, req->size);
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read_phys_req_item(req->addr, req, i, &req->data);
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}
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} else if (req->dir == IOREQ_WRITE) {
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for (i = 0; i < req->count; i++) {
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cpu_physical_memory_write(
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req->addr + (sign * i * (int64_t)req->size),
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(uint8_t *) &req->data, req->size);
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write_phys_req_item(req->addr, req, i, &req->data);
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}
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}
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} else {
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@ -743,21 +767,13 @@ static void cpu_ioreq_move(ioreq_t *req)
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if (req->dir == IOREQ_READ) {
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for (i = 0; i < req->count; i++) {
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cpu_physical_memory_read(
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req->addr + (sign * i * (int64_t)req->size),
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(uint8_t*) &tmp, req->size);
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cpu_physical_memory_write(
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req->data + (sign * i * (int64_t)req->size),
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(uint8_t*) &tmp, req->size);
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read_phys_req_item(req->addr, req, i, &tmp);
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write_phys_req_item(req->data, req, i, &tmp);
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}
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} else if (req->dir == IOREQ_WRITE) {
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for (i = 0; i < req->count; i++) {
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cpu_physical_memory_read(
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req->data + (sign * i * (int64_t)req->size),
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(uint8_t*) &tmp, req->size);
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cpu_physical_memory_write(
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req->addr + (sign * i * (int64_t)req->size),
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(uint8_t*) &tmp, req->size);
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read_phys_req_item(req->data, req, i, &tmp);
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write_phys_req_item(req->addr, req, i, &tmp);
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}
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}
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}
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