From: Jessica Yu jeyu@kernel.org
stable inclusion from stable-v5.10.118 commit 030de84d453a8ec3d99294246f8c07d845bb3828 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L686
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 33121347fb1c359bd6e3e680b9f2c6ced5734a81 upstream.
Dynamic code patching (alternatives, jump_label and static_call) can have sites in __exit code, even it __exit is never executed. Therefore __exit must be present at runtime, at least for as long as __init code is.
Additionally, for jump_label and static_call, the __exit sites must also identify as within_module_init(), such that the infrastructure is aware to never touch them after module init -- alternatives are only ran once at init and hence don't have this particular constraint.
By making __exit identify as __init for MODULE_UNLOAD, the above is satisfied.
So, when !CONFIG_MODULE_UNLOAD, the section ordering should look like the following, with the .exit sections moved to the init region of the module.
Core section allocation order: .text .rodata __ksymtab_gpl __ksymtab_strings .note.* sections .bss .data .gnu.linkonce.this_module Init section allocation order: .init.text .exit.text .symtab .strtab
[jeyu: thanks to Peter Zijlstra for most of changelog]
Link: https://lore.kernel.org/lkml/YFiuphGw0RKehWsQ@gunter/ Link: https://lore.kernel.org/r/20210323142756.11443-1-jeyu@kernel.org Acked-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Jessica Yu jeyu@kernel.org Cc: Joerg Vehlow lkml@jv-coder.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- kernel/module.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c index 1acdfba63716..de90f989c558 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2873,7 +2873,11 @@ void * __weak module_alloc(unsigned long size)
bool __weak module_init_section(const char *name) { +#ifndef CONFIG_MODULE_UNLOAD + return strstarts(name, ".init") || module_exit_section(name); +#else return strstarts(name, ".init"); +#endif }
bool __weak module_exit_section(const char *name) @@ -3186,11 +3190,6 @@ static int rewrite_section_headers(struct load_info *info, int flags) temporary image. */ shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
-#ifndef CONFIG_MODULE_UNLOAD - /* Don't load .exit sections */ - if (module_exit_section(info->secstrings+shdr->sh_name)) - shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; -#endif }
/* Track but don't keep modinfo and version sections. */