4.4-stable review patch. If anyone has any objections, please let me know.
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From: Rameshwar Prasad Sahu rsahu@apm.com
commit f1601113ddc0339a745e702f4fb1ca37d4875e65 upstream.
When tracing ata link error event, the kernel crashes when the disk is removed due to NULL pointer access by trace_ata_eh_link_autopsy API. This occurs as the dev is NULL when the disk disappeared. This patch fixes this crash by calling trace_ata_eh_link_autopsy only if "dev" is not NULL.
v2 changes: Removed direct passing "link" pointer instead of "dev" in trace API.
Signed-off-by: Rameshwar Prasad Sahu rsahu@apm.com Signed-off-by: Tejun Heo tj@kernel.org Fixes: 255c03d15a29 ("libata: Add tracepoints") Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/ata/libata-eh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -2245,8 +2245,8 @@ static void ata_eh_link_autopsy(struct a if (dev->flags & ATA_DFLAG_DUBIOUS_XFER) eflags |= ATA_EFLAG_DUBIOUS_XFER; ehc->i.action |= ata_eh_speed_down(dev, eflags, all_err_mask); + trace_ata_eh_link_autopsy(dev, ehc->i.action, all_err_mask); } - trace_ata_eh_link_autopsy(dev, ehc->i.action, all_err_mask); DPRINTK("EXIT\n"); }