[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] xentrace: handle sparse cpu ids correctly in xen trace buffer handling
commit 74584a367051bc0d6f4b96fd360fa7bc6538fc39 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Thu Oct 4 12:47:24 2018 +0100 Commit: George Dunlap <george.dunlap@xxxxxxxxxx> CommitDate: Thu Oct 4 12:47:24 2018 +0100 xentrace: handle sparse cpu ids correctly in xen trace buffer handling The per-cpu buffers for Xentrace are addressed by cpu-id, but the info array for the buffers is sized only by number of online cpus. This might lead to crashes when using Xentrace with smt=0. The t_info structure has to be sized based on nr_cpu_ids. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxxx> --- tools/xentrace/xentrace.c | 2 +- xen/common/trace.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/xentrace/xentrace.c b/tools/xentrace/xentrace.c index a9cb4b15a9..4b50b8a53e 100644 --- a/tools/xentrace/xentrace.c +++ b/tools/xentrace/xentrace.c @@ -600,7 +600,7 @@ static unsigned int get_num_cpus(void) exit(EXIT_FAILURE); } - return physinfo.nr_cpus; + return physinfo.max_cpu_id + 1; } /** diff --git a/xen/common/trace.c b/xen/common/trace.c index 8cdc17b731..cc294fc384 100644 --- a/xen/common/trace.c +++ b/xen/common/trace.c @@ -113,7 +113,7 @@ static int calculate_tbuf_size(unsigned int pages, uint16_t t_info_first_offset) struct t_info dummy_pages; typeof(dummy_pages.tbuf_size) max_pages; typeof(dummy_pages.mfn_offset[0]) max_mfn_offset; - unsigned int max_cpus = num_online_cpus(); + unsigned int max_cpus = nr_cpu_ids; unsigned int t_info_words; /* force maximum value for an unsigned type */ @@ -149,13 +149,13 @@ static int calculate_tbuf_size(unsigned int pages, uint16_t t_info_first_offset) /* * NB this calculation is correct, because t_info_first_offset is - * in words, not bytes, not bytes + * in words, not bytes */ - t_info_words = num_online_cpus() * pages + t_info_first_offset; + t_info_words = nr_cpu_ids * pages + t_info_first_offset; t_info_pages = PFN_UP(t_info_words * sizeof(uint32_t)); printk(XENLOG_INFO "xentrace: requesting %u t_info pages " "for %u trace pages on %u cpus\n", - t_info_pages, pages, num_online_cpus()); + t_info_pages, pages, nr_cpu_ids); return pages; } -- generated by git-patchbot for /home/xen/git/xen.git#staging _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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