kernel/linux.git/tools/perf/util/maps.c, branch v6.12.80

perf maps: Fix reference count leak in maps__find_ams()

2026-03-04T12:20:49+00:00

[ Upstream commit 6fdd2676db55b503c52dd3f1359b5c57f774ab75 ] ams and so ams->ms.map is an in argument, however, it is also overwritten. As a map is reference counted, ensure a map__put() is done before overwriting it. Fixes: 42fd623b58dbcc48 ("perf maps: Get map before returning in maps__find") Reviewed-by: James Clark Signed-off-by: Ian Rogers Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Athira Rajeev Cc: Bill Wendling Cc: Dr. David Alan Gilbert Cc: Guo Ren Cc: Howard Chu Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Garry Cc: Julia Lawall Cc: Justin Stitt Cc: Krzysztof Łopatowski Cc: Leo Yan Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Shimin Guo Cc: Suchit Karunakaran Cc: Thomas Falcon Cc: Tianyou Li Cc: Will Deacon Cc: Zecheng Li Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf maps: Fix display of kernel symbols

2025-02-08T08:57:31+00:00

[ Upstream commit dae29277fddaaf6670d17dfcbb916a2ca29c912f ] Since commit 659ad3492b913c90 ("perf maps: Switch from rbtree to lazily sorted array for addresses"), perf doesn't display anymore kernel symbols on powerpc, allthough it still detects them as kernel addresses. # Overhead Command Shared Object Symbol # ........ .......... ............. ...................................... # 80.49% Coeur main [unknown] [k] 0xc005f0f8 3.91% Coeur main gau [.] engine_loop.constprop.0.isra.0 1.72% Coeur main [unknown] [k] 0xc005f11c 1.09% Coeur main [unknown] [k] 0xc01f82c8 0.44% Coeur main libc.so.6 [.] epoll_wait 0.38% Coeur main [unknown] [k] 0xc0011718 0.36% Coeur main [unknown] [k] 0xc01f45c0 This is because function maps__find_next_entry() now returns current entry instead of next entry, leading to kernel map end address getting mis-configured with its own start address instead of the start address of the following map. Fix it by really taking the next entry, also make sure that entry follows current one by making sure entries are sorted. Fixes: 659ad3492b913c90 ("perf maps: Switch from rbtree to lazily sorted array for addresses") Reviewed-by: Arnaldo Carvalho de Melo Reviewed-by: Ian Rogers Signed-off-by: Christophe Leroy Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/2ea4501209d5363bac71a6757fe91c0747558a42.1736329923.git.christophe.leroy@csgroup.eu Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf maps: Add/use a sorted insert for fixup overlap and insert

2024-06-07T06:31:30+00:00

Data may have lots of overlapping mmaps. The regular insert adds at the end and relies on a later sort. For data with overlapping mappings the sort will happen during a subsequent maps__find or __maps__fixup_overlap_and_insert, there's never a period where the inserted maps buffer up and a single sort happens. To avoid back to back sorts, maintain the sort order when fixing up and inserting. Previously the first_ending_after search was O(log n) where n is the size of maps, and the insert was O(1) but because of the continuous sorting was becoming O(n*log(n)). With maintaining sort order, the insert now becomes O(n) for a memmove. For a perf report on a perf.data file containing overlapping mappings the time numbers are: Before: real 0m5.894s user 0m5.650s sys 0m0.231s After: real 0m0.675s user 0m0.454s sys 0m0.196s Signed-off-by: Ian Rogers Reviewed-by: James Clark Cc: Steinar H . Gunderson Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240521165109.708593-4-irogers@google.com

perf maps: Reduce sorting for overlapping mappings

2024-06-07T06:31:15+00:00

When an 'after' map is generated the 'new' map must be before it so terminate iterating and don't resort. If the entry 'pos' is entirely overlapped by the 'new' mapping then don't remove and insert the mapping, just replace - again to remove sorting. For a perf report on a perf.data file containing overlapping mappings the time numbers are: Before: real 0m9.856s user 0m9.637s sys 0m0.204s After: real 0m5.894s user 0m5.650s sys 0m0.231s Signed-off-by: Ian Rogers Reviewed-by: James Clark Cc: Steinar H . Gunderson Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240521165109.708593-3-irogers@google.com

perf maps: Fix use after free in mapsfixup_overlap_and_insert

2024-06-07T06:30:58+00:00

In the case 'before' and 'after' are broken out from pos, maps_by_address may be changed by __maps__insert, as such it needs re-reading. Don't ignore the return value from __maps_insert. Fixes: 659ad3492b91 ("perf maps: Switch from rbtree to lazily sorted array for addresses") Signed-off-by: Ian Rogers Reviewed-by: James Clark Cc: Steinar H . Gunderson Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240521165109.708593-2-irogers@google.com

perf maps: Re-use mapsfree_maps_by_name()

2024-05-09T21:48:19+00:00

maps__merge_in() hard codes the steps to free the maps_by_name list. It seems to not map__put() each element before freeing, and it sets maps_by_name_sorted to true after freeing, which may be harmless but is inconsistent with maps__init() and other functions. maps__maps_by_name_addr() is also quite hard to read because we already have maps__maps_by_name() and maps__maps_by_address(), but the function is only used in that place so delete it. Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240507141210.195939-3-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Add reference count checking and accessor functions

2024-05-06T18:28:49+00:00

Add reference count checking to struct dso, this can help with implementing correct reference counting discipline. To avoid RC_CHK_ACCESS everywhere, add accessor functions for the variables in struct dso. The majority of the change is mechanical in nature and not easy to split up. Committer testing: 'perf test' up to this patch shows no regressions. But: util/symbol.c: In function ‘dso__load_bfd_symbols’: util/symbol.c:1683:9: error: too few arguments to function ‘dso__set_adjust_symbols’ 1683 | dso__set_adjust_symbols(dso); | ^~~~~~~~~~~~~~~~~~~~~~~ In file included from util/symbol.c:21: util/dso.h:268:20: note: declared here 268 | static inline void dso__set_adjust_symbols(struct dso *dso, bool val) | ^~~~~~~~~~~~~~~~~~~~~~~ make[6]: *** [/home/acme/git/perf-tools-next/tools/build/Makefile.build:106: /tmp/tmp.ZWHbQftdN6/util/symbol.o] Error 1 MKDIR /tmp/tmp.ZWHbQftdN6/tests/workloads/ make[6]: *** Waiting for unfinished jobs.... This was updated: - symbols__fixup_end(&dso->symbols, false); - symbols__fixup_duplicate(&dso->symbols); - dso->adjust_symbols = 1; + symbols__fixup_end(dso__symbols(dso), false); + symbols__fixup_duplicate(dso__symbols(dso)); + dso__set_adjust_symbols(dso); But not build tested with BUILD_NONDISTRO and libbfd devel files installed (binutils-devel on fedora). Add the missing argument: symbols__fixup_end(dso__symbols(dso), false); symbols__fixup_duplicate(dso__symbols(dso)); - dso__set_adjust_symbols(dso); + dso__set_adjust_symbols(dso, true); Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Ahelenia Ziemiańska Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Ben Gainey Cc: Changbin Du Cc: Chengen Du Cc: Colin Ian King Cc: Dima Kogan Cc: Ilkka Koskinen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Paran Lee Cc: Peter Zijlstra Cc: Song Liu Cc: Sun Haiyong Cc: Thomas Richter Cc: Tiezhu Yang Cc: Yanteng Si Cc: zhaimingbing Link: https://lore.kernel.org/r/20240504213803.218974-6-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Remove check_invariants() from maps__lock()

2024-05-02T19:35:47+00:00

I found that the debug build was a slowed down a lot by the maps lock code since it checks the invariants whenever it gets the pointer to the lock. This means it checks twice the invariants before and after the access. Instead, let's move the checking code within the lock area but after any modification and remove it from the read paths. This would remove (more than) half of the maps lock overhead. The time for perf report with a huge data file (200k+ of MMAP2 events). Non-debug Before After --------- -------- -------- 2m 43s 6m 45s 4m 21s Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240429225738.1491791-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf map: Fix map reference count issues

2024-03-01T02:06:00+00:00

The find will get the map, ensure puts are done on all paths. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Masami Hiramatsu Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240229062048.558799-1-irogers@google.com

perf maps: Locking tidy up of nr_maps

2024-02-12T20:35:41+00:00

After this change maps__nr_maps is only used by tests, existing users are migrated to maps__empty. Compute maps__empty under the read lock. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: K Prateek Nayak Cc: James Clark Cc: Vincent Whitchurch Cc: Alexey Dobriyan Cc: Colin Ian King Cc: Changbin Du Cc: Masami Hiramatsu Cc: Song Liu Cc: Leo Yan Cc: Athira Rajeev Cc: Liam Howlett Cc: Artem Savkov Cc: bpf@vger.kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240210031746.4057262-7-irogers@google.com