Commit d9aa3af0 authored by Krzysztof Helt's avatar Krzysztof Helt Committed by James Bottomley
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[SCSI] sym53c8xx: fixes two bugs related to chip reset



This patch fixes two bugs pointed by James Bottomley:

 1. the if (!sym_data->io_reset).  That variable is only ever filled
    by a stack based completion.  If we find it non empty it means
    this code has been entered twice and we have a severe problem,
    so that should just become a BUG_ON(sym_data->io_reset).
 2. sym_data->io_reset should be set to NULL before the routine is
    exited otherwise the PCI recovery code could end up completing
    what will be a bogus pointer into the stack.

Big thanks to James Bottomley for help with the patch.
Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@w.pl>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 3a0086a8
......@@ -609,22 +609,24 @@ static int sym_eh_handler(int op, char *opname, struct scsi_cmnd *cmd)
*/
#define WAIT_FOR_PCI_RECOVERY 35
if (pci_channel_offline(pdev)) {
struct completion *io_reset;
int finished_reset = 0;
init_completion(&eh_done);
spin_lock_irq(shost->host_lock);
/* Make sure we didn't race */
if (pci_channel_offline(pdev)) {
if (!sym_data->io_reset)
sym_data->io_reset = &eh_done;
io_reset = sym_data->io_reset;
BUG_ON(sym_data->io_reset);
sym_data->io_reset = &eh_done;
} else {
finished_reset = 1;
}
spin_unlock_irq(shost->host_lock);
if (!finished_reset)
finished_reset = wait_for_completion_timeout(io_reset,
finished_reset = wait_for_completion_timeout
(sym_data->io_reset,
WAIT_FOR_PCI_RECOVERY*HZ);
spin_lock_irq(shost->host_lock);
sym_data->io_reset = NULL;
spin_unlock_irq(shost->host_lock);
if (!finished_reset)
return SCSI_FAILED;
}
......@@ -1879,7 +1881,6 @@ static void sym2_io_resume(struct pci_dev *pdev)
spin_lock_irq(shost->host_lock);
if (sym_data->io_reset)
complete_all(sym_data->io_reset);
sym_data->io_reset = NULL;
spin_unlock_irq(shost->host_lock);
}
......
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