From 5638fd9c41829f59dba054a67a6fd955006f9a85 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 31 Aug 2023 13:06:25 +0200 Subject: [PATCH] 6.5-stable patches added patches: kallsyms-fix-kallsyms_selftest-failure.patch --- ...llsyms-fix-kallsyms_selftest-failure.patch | 135 ++++++++++++++++++ queue-6.5/series | 1 + 2 files changed, 136 insertions(+) create mode 100644 queue-6.5/kallsyms-fix-kallsyms_selftest-failure.patch diff --git a/queue-6.5/kallsyms-fix-kallsyms_selftest-failure.patch b/queue-6.5/kallsyms-fix-kallsyms_selftest-failure.patch new file mode 100644 index 00000000000..112831f1da6 --- /dev/null +++ b/queue-6.5/kallsyms-fix-kallsyms_selftest-failure.patch @@ -0,0 +1,135 @@ +From 33f0467fe06934d5e4ea6e24ce2b9c65ce618e26 Mon Sep 17 00:00:00 2001 +From: Yonghong Song +Date: Thu, 24 Aug 2023 20:46:59 -0700 +Subject: kallsyms: Fix kallsyms_selftest failure + +From: Yonghong Song + +commit 33f0467fe06934d5e4ea6e24ce2b9c65ce618e26 upstream. + +Kernel test robot reported a kallsyms_test failure when clang lto is +enabled (thin or full) and CONFIG_KALLSYMS_SELFTEST is also enabled. +I can reproduce in my local environment with the following error message +with thin lto: + [ 1.877897] kallsyms_selftest: Test for 1750th symbol failed: (tsc_cs_mark_unstable) addr=ffffffff81038090 + [ 1.877901] kallsyms_selftest: abort + +It appears that commit 8cc32a9bbf29 ("kallsyms: strip LTO-only suffixes +from promoted global functions") caused the failure. Commit 8cc32a9bbf29 +changed cleanup_symbol_name() based on ".llvm." instead of '.' where +".llvm." is appended to a before-lto-optimization local symbol name. +We need to propagate such knowledge in kallsyms_selftest.c as well. + +Further more, compare_symbol_name() in kallsyms.c needs change as well. +In scripts/kallsyms.c, kallsyms_names and kallsyms_seqs_of_names are used +to record symbol names themselves and index to symbol names respectively. +For example: + kallsyms_names: + ... + __amd_smn_rw._entry <== seq 1000 + __amd_smn_rw._entry.5 <== seq 1001 + __amd_smn_rw.llvm. <== seq 1002 + ... + +kallsyms_seqs_of_names are sorted based on cleanup_symbol_name() through, so +the order in kallsyms_seqs_of_names actually has + + index 1000: seq 1002 <== __amd_smn_rw.llvm. (actual symbol comparison using '__amd_smn_rw') + index 1001: seq 1000 <== __amd_smn_rw._entry + index 1002: seq 1001 <== __amd_smn_rw._entry.5 + +Let us say at a particular point, at index 1000, symbol '__amd_smn_rw.llvm.' +is comparing to '__amd_smn_rw._entry' where '__amd_smn_rw._entry' is the one to +search e.g., with function kallsyms_on_each_match_symbol(). The current implementation +will find out '__amd_smn_rw._entry' is less than '__amd_smn_rw.llvm.' and +then continue to search e.g., index 999 and never found a match although the actual +index 1001 is a match. + +To fix this issue, let us do cleanup_symbol_name() first and then do comparison. +In the above case, comparing '__amd_smn_rw' vs '__amd_smn_rw._entry' and +'__amd_smn_rw._entry' being greater than '__amd_smn_rw', the next comparison will +be > index 1000 and eventually index 1001 will be hit an a match is found. + +For any symbols not having '.llvm.' substr, there is no functionality change +for compare_symbol_name(). + +Fixes: 8cc32a9bbf29 ("kallsyms: strip LTO-only suffixes from promoted global functions") +Reported-by: kernel test robot +Closes: https://lore.kernel.org/oe-lkp/202308232200.1c932a90-oliver.sang@intel.com +Signed-off-by: Yonghong Song +Reviewed-by: Song Liu +Reviewed-by: Zhen Lei +Link: https://lore.kernel.org/r/20230825034659.1037627-1-yonghong.song@linux.dev +Cc: stable@vger.kernel.org +Signed-off-by: Kees Cook +Signed-off-by: Greg Kroah-Hartman +--- + kernel/kallsyms.c | 17 +++++++---------- + kernel/kallsyms_selftest.c | 23 +---------------------- + 2 files changed, 8 insertions(+), 32 deletions(-) + +--- a/kernel/kallsyms.c ++++ b/kernel/kallsyms.c +@@ -188,16 +188,13 @@ static bool cleanup_symbol_name(char *s) + + static int compare_symbol_name(const char *name, char *namebuf) + { +- int ret; +- +- ret = strcmp(name, namebuf); +- if (!ret) +- return ret; +- +- if (cleanup_symbol_name(namebuf) && !strcmp(name, namebuf)) +- return 0; +- +- return ret; ++ /* The kallsyms_seqs_of_names is sorted based on names after ++ * cleanup_symbol_name() (see scripts/kallsyms.c) if clang lto is enabled. ++ * To ensure correct bisection in kallsyms_lookup_names(), do ++ * cleanup_symbol_name(namebuf) before comparing name and namebuf. ++ */ ++ cleanup_symbol_name(namebuf); ++ return strcmp(name, namebuf); + } + + static unsigned int get_symbol_seq(int index) +--- a/kernel/kallsyms_selftest.c ++++ b/kernel/kallsyms_selftest.c +@@ -196,7 +196,7 @@ static bool match_cleanup_name(const cha + if (!IS_ENABLED(CONFIG_LTO_CLANG)) + return false; + +- p = strchr(s, '.'); ++ p = strstr(s, ".llvm."); + if (!p) + return false; + +@@ -344,27 +344,6 @@ static int test_kallsyms_basic_function( + goto failed; + } + +- /* +- * The first '.' may be the initial letter, in which case the +- * entire symbol name will be truncated to an empty string in +- * cleanup_symbol_name(). Do not test these symbols. +- * +- * For example: +- * cat /proc/kallsyms | awk '{print $3}' | grep -E "^\." | head +- * .E_read_words +- * .E_leading_bytes +- * .E_trailing_bytes +- * .E_write_words +- * .E_copy +- * .str.292.llvm.12122243386960820698 +- * .str.24.llvm.12122243386960820698 +- * .str.29.llvm.12122243386960820698 +- * .str.75.llvm.12122243386960820698 +- * .str.99.llvm.12122243386960820698 +- */ +- if (IS_ENABLED(CONFIG_LTO_CLANG) && !namebuf[0]) +- continue; +- + lookup_addr = kallsyms_lookup_name(namebuf); + + memset(stat, 0, sizeof(*stat)); diff --git a/queue-6.5/series b/queue-6.5/series index 3700da06caf..f602bf5fff7 100644 --- a/queue-6.5/series +++ b/queue-6.5/series @@ -5,3 +5,4 @@ arm-module-use-module_init_layout_section-to-spot-init-sections.patch module-decompress-use-vmalloc-for-zstd-decompression-workspace.patch ipv6-remove-hard-coded-limitation-on-ipv6_pinfo.patch lockdep-fix-static-memory-detection-even-more.patch +kallsyms-fix-kallsyms_selftest-failure.patch -- 2.47.3