diff options
Diffstat (limited to '0003-trace-Support-module-memory-layout-change-on-Linux-6.patch')
| -rw-r--r-- | 0003-trace-Support-module-memory-layout-change-on-Linux-6.patch | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/0003-trace-Support-module-memory-layout-change-on-Linux-6.patch b/0003-trace-Support-module-memory-layout-change-on-Linux-6.patch new file mode 100644 index 0000000..205ae1e --- /dev/null +++ b/0003-trace-Support-module-memory-layout-change-on-Linux-6.patch @@ -0,0 +1,126 @@ +From c5913a960dfa07d64397e6b591e6f0d40ea0b503 Mon Sep 17 00:00:00 2001 +From: HATAYAMA Daisuke <d.hatayama@fujitsu.com> +Date: Tue, 26 Sep 2023 02:55:49 -0400 +Subject: [PATCH] trace: Support module memory layout change on Linux 6.4 + +Linux kernel introduced new module memory layout on Linux 6.4 at the +commit ac3b432 (module: replace module_layout with module_memory) and +crash utility supported it at the commit 7750e61 (Support module +memory layout change on Linux 6.4). + +In the change, crash utility changed definition and usage of data +structure for kernel modules. However, crash trace also refers to the +data structures. As a result, with the crash utility with the change, +crash trace command results in segmentation fault: + + crash> extend trace.so + /usr/lib64/crash/extensions/trace.so: shared object loaded + crash> trace show + Segmentation fault (core dumped) + +To fix this issue, let's support the new definition and usage of +struct load_module in crash trace. This is at the same time intended +for crash trace to support the new module memory layout of the Linux +kernel. + +On the other hand, there is still inevitable dependency left to size +of struct load_module, one of the data structures of crash utility, in +crash trace. struct symbol_table_data holds an array of objects of +struct load_module in member variable load_modules and we need to know +size of struct load_module in advance to refer to its elements. + + struct symbol_table_data { + ...snip... + int mods_installed; + struct load_module *current; + struct load_module *load_modules; + +Due to this, once crash trace is built with the defs.h including +change of size of struct load_module, it can never be used with the +older crash utility that was built with a different size of struct +load_module. + +Because there is no preferable way to tackle the dependency without +altering implementation of crash utility, we have no choice but accept +breaking backward-compatibility for the time being. + +Signed-off-by: HATAYAMA Daisuke <d.hatayama@fujitsu.com> +Signed-off-by: Lianbo Jiang <lijiang@redhat.com> +--- + trace.c | 49 +++++++++++++++++++++++++++++++++++++++++++++---- + 1 file changed, 45 insertions(+), 4 deletions(-) + +diff --git a/trace.c b/trace.c +index c33907f98b00..9e51707da5f7 100644 +--- a/trace.c ++++ b/trace.c +@@ -2219,14 +2219,11 @@ fail: + return -1; + } + +-static int save_proc_kallsyms(int fd) ++static void __save_proc_kallsyms_mod_legacy(void) + { + int i; + struct syment *sp; + +- for (sp = st->symtable; sp < st->symend; sp++) +- tmp_fprintf("%lx %c %s\n", sp->value, sp->type, sp->name); +- + for (i = 0; i < st->mods_installed; i++) { + struct load_module *lm = &st->load_modules[i]; + +@@ -2239,6 +2236,50 @@ static int save_proc_kallsyms(int fd) + sp->name, lm->mod_name); + } + } ++} ++ ++#ifdef MODULE_MEMORY ++static void __save_proc_kallsyms_mod_v6_4(void) ++{ ++ int i, t; ++ struct syment *sp; ++ ++ for (i = 0; i < st->mods_installed; i++) { ++ struct load_module *lm = &st->load_modules[i]; ++ ++ for_each_mod_mem_type(t) { ++ if (!lm->symtable[t]) ++ continue; ++ ++ for (sp = lm->symtable[t]; sp <= lm->symend[t]; sp++) { ++ if (!strncmp(sp->name, "_MODULE_", strlen("_MODULE_"))) ++ continue; ++ ++ /* Currently sp->type for modules is not trusted */ ++ tmp_fprintf("%lx %c %s\t[%s]\n", sp->value, 'm', ++ sp->name, lm->mod_name); ++ } ++ } ++ } ++} ++#else ++#define MODULE_MEMORY() (0) ++static inline void __save_proc_kallsyms_mod_v6_4(void) ++{ ++} ++#endif ++ ++static int save_proc_kallsyms(int fd) ++{ ++ struct syment *sp; ++ ++ for (sp = st->symtable; sp < st->symend; sp++) ++ tmp_fprintf("%lx %c %s\n", sp->value, sp->type, sp->name); ++ ++ if (MODULE_MEMORY()) ++ __save_proc_kallsyms_mod_v6_4(); ++ else ++ __save_proc_kallsyms_mod_legacy(); + + if (tmp_file_record_size4(fd)) + return -1; +-- +2.41.0 + |