Commit ce0d998b authored by Adrian Hunter's avatar Adrian Hunter Committed by Peter Zijlstra

perf/x86/intel/pt: Fix sampling using single range output

Deal with errata TGL052, ADL037 and RPL017 "Trace May Contain Incorrect
Data When Configured With Single Range Output Larger Than 4KB" by
disabling single range output whenever larger than 4KB.

Fixes: 67063847 ("perf/x86/intel/pt: Opportunistically use single range output mode")
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221112151508.13768-1-adrian.hunter@intel.com
parent baa014b9
...@@ -1263,6 +1263,15 @@ static int pt_buffer_try_single(struct pt_buffer *buf, int nr_pages) ...@@ -1263,6 +1263,15 @@ static int pt_buffer_try_single(struct pt_buffer *buf, int nr_pages)
if (1 << order != nr_pages) if (1 << order != nr_pages)
goto out; goto out;
/*
* Some processors cannot always support single range for more than
* 4KB - refer errata TGL052, ADL037 and RPL017. Future processors might
* also be affected, so for now rather than trying to keep track of
* which ones, just disable it for all.
*/
if (nr_pages > 1)
goto out;
buf->single = true; buf->single = true;
buf->nr_pages = nr_pages; buf->nr_pages = nr_pages;
ret = 0; ret = 0;
......
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