From: Michael Petlan <mpetlan@redhat.com> stable inclusion from stable-v5.10.108 commit 204d38dc6a8196ad57bd53f55d2cd4b13c1fa3e1 bugzilla: https://gitee.com/openeuler/kernel/issues/I574A9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 3cf6a32f3f2a45944dd5be5c6ac4deb46bcd3bee upstream. Before this patch, the symbol end address fixup to be called, needed two conditions being met: if (prev->end == prev->start && prev->end != curr->start) Where "prev->end == prev->start" means that prev is zero-long (and thus needs a fixup) and "prev->end != curr->start" means that fixup hasn't been applied yet However, this logic is incorrect in the following situation: *curr = {rb_node = {__rb_parent_color = 278218928, rb_right = 0x0, rb_left = 0x0}, start = 0xc000000000062354, end = 0xc000000000062354, namelen = 40, type = 2 '\002', binding = 0 '\000', idle = 0 '\000', ignore = 0 '\000', inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false, name = 0x1159739e "kprobe_optinsn_page\t[__builtin__kprobes]"} *prev = {rb_node = {__rb_parent_color = 278219041, rb_right = 0x109548b0, rb_left = 0x109547c0}, start = 0xc000000000062354, end = 0xc000000000062354, namelen = 12, type = 2 '\002', binding = 1 '\001', idle = 0 '\000', ignore = 0 '\000', inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false, name = 0x1095486e "optinsn_slot"} In this case, prev->start == prev->end == curr->start == curr->end, thus the condition above thinks that "we need a fixup due to zero length of prev symbol, but it has been probably done, since the prev->end == curr->start", which is wrong. After the patch, the execution path proceeds to arch__symbols__fixup_end function which fixes up the size of prev symbol by adding page_size to its end offset. Fixes: 3b01a413c196c910 ("perf symbols: Improve kallsyms symbol end addr calculation") Signed-off-by: Michael Petlan <mpetlan@redhat.com> Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Link: http://lore.kernel.org/lkml/20220317135536.805-1-mpetlan@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- tools/perf/util/symbol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 4d569ad7db02..3609da7cce0a 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -231,7 +231,7 @@ void symbols__fixup_end(struct rb_root_cached *symbols) prev = curr; curr = rb_entry(nd, struct symbol, rb_node); - if (prev->end == prev->start && prev->end != curr->start) + if (prev->end == prev->start || prev->end != curr->start) arch__symbols__fixup_end(prev, curr); } -- 2.20.1