Messages in this thread Patch in this message | | | From | Todd Poynor <> | Subject | [PATCH 13/15] staging: gasket: core: protect against races during unregister | Date | Sun, 5 Aug 2018 13:07:47 -0700 |
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From: Todd Poynor <toddpoynor@google.com>
Keep mutex held across the unregistration operation, until the driver_desc field of the global table is removed, to prevent a concurrent accessor from looking up the driver_desc while gasket_unregister_device() is in the processing of removing it.
Reported-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Todd Poynor <toddpoynor@google.com> --- drivers/staging/gasket/gasket_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c index ace92f107ed58..a6462b6d702f1 100644 --- a/drivers/staging/gasket/gasket_core.c +++ b/drivers/staging/gasket/gasket_core.c @@ -1765,9 +1765,9 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) break; } } - mutex_unlock(&g_mutex); if (!internal_desc) { + mutex_unlock(&g_mutex); pr_err("request to unregister unknown desc: %s, %d:%d\n", driver_desc->name, driver_desc->major, driver_desc->minor); @@ -1780,7 +1780,6 @@ void gasket_unregister_device(const struct gasket_driver_desc *driver_desc) class_destroy(internal_desc->class); /* Finally, effectively "remove" the driver. */ - mutex_lock(&g_mutex); g_descs[desc_idx].driver_desc = NULL; mutex_unlock(&g_mutex); -- 2.18.0.597.ga71716f1ad-goog
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