Am 07.01.20 um 20:25 schrieb Tianlin Li:
Right now several architectures allow their set_memory_*() family of functions to fail, but callers may not be checking the return values. If set_memory_*() returns with an error, call-site assumptions may be infact wrong to assume that it would either succeed or not succeed at all. Ideally, the failure of set_memory_*() should be passed up the call stack, and callers should examine the failure and deal with it. Need to fix the callers and add the __must_check attribute. They also may not provide any level of atomicity, in the sense that the memory protections may be left incomplete on failure. This issue likely has a few steps on effects architectures: 1)Have all callers of set_memory_*() helpers check the return value. 2)Add __must_check to all set_memory_*() helpers so that new uses do not ignore the return value. 3)Add atomicity to the calls so that the memory protections aren't left in a partial state. This series is part of step 1. Make drm/radeon check the return value of set_memory_*().
I'm a little hesitate merge that. This hardware is >15 years old and nobody of the developers have any system left to test this change on.
Would it be to much of a problem to just add something like: r = set_memory_*(); (void)r; /* Intentionally ignored */.
Apart from that certainly a good idea to add __must_check to the functions. Regards, Christian.
Tianlin Li (2): drm/radeon: have the callers of set_memory_*() check the return value drm/radeon: change call sites to handle return value properly. drivers/gpu/drm/radeon/r100.c | 3 ++- drivers/gpu/drm/radeon/radeon.h | 2 +- drivers/gpu/drm/radeon/radeon_gart.c | 22 ++++++++++++++++++---- drivers/gpu/drm/radeon/rs400.c | 3 ++- 4 files changed, 23 insertions(+), 7 deletions(-)
