From: Rameshwar Prasad Sahu Date: Thu, 2 Nov 2017 11:01:07 +0000 (+0530) Subject: ata: fixes kernel crash while tracing ata_eh_link_autopsy event X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~1170 X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/%22mailto:kde%40ewsoftware.de//%22style.css/%22/%22http:/www.example.com/%22mailto:kde%40ewsoftware.de/%22style.css/%22?a=commitdiff_plain;h=2946ebe90ecf7f506e3e1fc49d41406bfaade551;p=linux-4.9.git ata: fixes kernel crash while tracing ata_eh_link_autopsy event 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 Signed-off-by: Tejun Heo Fixes: 255c03d15a29 ("libata: Add tracepoints") Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 0e1ec37070d1..6475a1343483 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -2329,8 +2329,8 @@ static void ata_eh_link_autopsy(struct ata_link *link) 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"); }