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ide: introduce ide_transfer_start_norecurse 

For the case where the end_transfer_func is also the caller of
ide_transfer_start, the mutual recursion can lead to unlimited
stack usage.  Introduce a new version that can be used to change
tail recursion into a loop, and use it in trace_ide_atapi_cmd_reply_end.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180606190955.20845-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This commit is contained in:
Paolo Bonzini 2018-06-06 15:09:55 -04:00 committed by John Snow
parent d02cea6437
commit c173723f24
3 changed files with 37 additions and 23 deletions
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42
hw/ide/atapi.c
View File

@ -245,15 +245,11 @@ static uint16_t atapi_byte_count_limit(IDEState *s)
void ide_atapi_cmd_reply_end(IDEState *s)
{
int byte_count_limit, size, ret;
trace_ide_atapi_cmd_reply_end(s, s->packet_transfer_size,
s->elementary_transfer_size,
s->io_buffer_index);
if (s->packet_transfer_size <= 0) {
/* end of transfer */
ide_atapi_cmd_ok(s);
ide_set_irq(s->bus);
trace_ide_atapi_cmd_reply_end_eot(s, s->status);
} else {
while (s->packet_transfer_size > 0) {
trace_ide_atapi_cmd_reply_end(s, s->packet_transfer_size,
s->elementary_transfer_size,
s->io_buffer_index);
/* see if a new sector must be read */
if (s->lba != -1 && s->io_buffer_index >= s->cd_sector_size) {
if (!s->elementary_transfer_size) {
@ -279,11 +275,6 @@ void ide_atapi_cmd_reply_end(IDEState *s)
size = s->cd_sector_size - s->io_buffer_index;
if (size > s->elementary_transfer_size)
size = s->elementary_transfer_size;
s->packet_transfer_size -= size;
s->elementary_transfer_size -= size;
s->io_buffer_index += size;
ide_transfer_start(s, s->io_buffer + s->io_buffer_index - size,
size, ide_atapi_cmd_reply_end);
} else {
/* a new transfer is needed */
s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO;
@ -306,13 +297,26 @@ void ide_atapi_cmd_reply_end(IDEState *s)
size = (s->cd_sector_size - s->io_buffer_index);
}
trace_ide_atapi_cmd_reply_end_new(s, s->status);
s->packet_transfer_size -= size;
s->elementary_transfer_size -= size;
s->io_buffer_index += size;
ide_transfer_start(s, s->io_buffer + s->io_buffer_index - size,
size, ide_atapi_cmd_reply_end);
}
s->packet_transfer_size -= size;
s->elementary_transfer_size -= size;
s->io_buffer_index += size;
/* Some adapters process PIO data right away. In that case, we need
* to avoid mutual recursion between ide_transfer_start
* and ide_atapi_cmd_reply_end.
*/
if (!ide_transfer_start_norecurse(s,
s->io_buffer + s->io_buffer_index - size,
size, ide_atapi_cmd_reply_end)) {
return;
}
}
/* end of transfer */
trace_ide_atapi_cmd_reply_end_eot(s, s->status);
ide_atapi_cmd_ok(s);
ide_set_irq(s->bus);
}
/* send a reply of 'size' bytes in s->io_buffer to an ATAPI command */

16
hw/ide/core.c
View File

@ -523,8 +523,8 @@ static void ide_clear_retry(IDEState *s)
}
/* prepare data transfer and tell what to do after */
void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
EndTransferFunc *end_transfer_func)
bool ide_transfer_start_norecurse(IDEState *s, uint8_t *buf, int size,
EndTransferFunc *end_transfer_func)
{
s->data_ptr = buf;
s->data_end = buf + size;
@ -534,10 +534,18 @@ void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
}
if (!s->bus->dma->ops->pio_transfer) {
s->end_transfer_func = end_transfer_func;
return;
return false;
}
s->bus->dma->ops->pio_transfer(s->bus->dma);
end_transfer_func(s);
return true;
}
void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
EndTransferFunc *end_transfer_func)
{
if (ide_transfer_start_norecurse(s, buf, size, end_transfer_func)) {
end_transfer_func(s);
}
}
static void ide_cmd_done(IDEState *s)

2
include/hw/ide/internal.h
View File

@ -623,6 +623,8 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val);
void ide_transfer_start(IDEState *s, uint8_t *buf, int size,
EndTransferFunc *end_transfer_func);
bool ide_transfer_start_norecurse(IDEState *s, uint8_t *buf, int size,
EndTransferFunc *end_transfer_func);
void ide_transfer_stop(IDEState *s);
void ide_set_inactive(IDEState *s, bool more);
BlockAIOCB *ide_issue_trim(