From 15d5daa0a7006b9bd4dcc49f90e7ac8ddbe102f2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 17 May 2023 15:18:07 +0200 Subject: kallsyms: remove unused arch_get_kallsym() helper The arch_get_kallsym() function was introduced so that x86 could override it, but that override was removed in bf904d2762ee ("x86/pti/64: Remove the SYSCALL64 entry trampoline"), so now this does nothing except causing a warning about a missing prototype: kernel/kallsyms.c:662:12: error: no previous prototype for 'arch_get_kallsym' [-Werror=missing-prototypes] 662 | int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value, Restore the old behavior before d83212d5dd67 ("kallsyms, x86: Export addresses of PTI entry trampolines") to simplify the code and avoid the warning. Signed-off-by: Arnd Bergmann Tested-by: Alan Maguire [mcgrof: fold in bpf selftest fix] Signed-off-by: Luis Chamberlain --- kernel/kallsyms.c | 28 +--------------------------- 1 file changed, 1 insertion(+), 27 deletions(-) (limited to 'kernel/kallsyms.c') diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 77747391f49b..290d8cc1943a 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -646,7 +646,6 @@ int sprint_backtrace_build_id(char *buffer, unsigned long address) /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ struct kallsym_iter { loff_t pos; - loff_t pos_arch_end; loff_t pos_mod_end; loff_t pos_ftrace_mod_end; loff_t pos_bpf_end; @@ -659,29 +658,9 @@ struct kallsym_iter { int show_value; }; -int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value, - char *type, char *name) -{ - return -EINVAL; -} - -static int get_ksymbol_arch(struct kallsym_iter *iter) -{ - int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms, - &iter->value, &iter->type, - iter->name); - - if (ret < 0) { - iter->pos_arch_end = iter->pos; - return 0; - } - - return 1; -} - static int get_ksymbol_mod(struct kallsym_iter *iter) { - int ret = module_get_kallsym(iter->pos - iter->pos_arch_end, + int ret = module_get_kallsym(iter->pos - kallsyms_num_syms, &iter->value, &iter->type, iter->name, iter->module_name, &iter->exported); @@ -764,7 +743,6 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) iter->nameoff = get_symbol_offset(new_pos); iter->pos = new_pos; if (new_pos == 0) { - iter->pos_arch_end = 0; iter->pos_mod_end = 0; iter->pos_ftrace_mod_end = 0; iter->pos_bpf_end = 0; @@ -780,10 +758,6 @@ static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) { iter->pos = pos; - if ((!iter->pos_arch_end || iter->pos_arch_end > pos) && - get_ksymbol_arch(iter)) - return 1; - if ((!iter->pos_mod_end || iter->pos_mod_end > pos) && get_ksymbol_mod(iter)) return 1; -- cgit v1.2.3 From 4f521bab5bfc854ec0dab7ef560dfa75247e615d Mon Sep 17 00:00:00 2001 From: Maninder Singh Date: Fri, 26 May 2023 12:51:23 +0530 Subject: kallsyms: remove unsed API lookup_symbol_attrs with commit '7878c231dae0 ("slab: remove /proc/slab_allocators")' lookup_symbol_attrs usage is removed. Thus removing redundant API. Signed-off-by: Maninder Singh Reviewed-by: Kees Cook Signed-off-by: Luis Chamberlain --- kernel/kallsyms.c | 28 ---------------------------- 1 file changed, 28 deletions(-) (limited to 'kernel/kallsyms.c') diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 290d8cc1943a..8193e947aa10 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -484,34 +484,6 @@ found: return 0; } -int lookup_symbol_attrs(unsigned long addr, unsigned long *size, - unsigned long *offset, char *modname, char *name) -{ - int res; - - name[0] = '\0'; - name[KSYM_NAME_LEN - 1] = '\0'; - - if (is_ksym_addr(addr)) { - unsigned long pos; - - pos = get_symbol_pos(addr, size, offset); - /* Grab name */ - kallsyms_expand_symbol(get_symbol_offset(pos), - name, KSYM_NAME_LEN); - modname[0] = '\0'; - goto found; - } - /* See if it's in a module. */ - res = lookup_module_symbol_attrs(addr, size, offset, modname, name); - if (res) - return res; - -found: - cleanup_symbol_name(name); - return 0; -} - /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, int symbol_offset, int add_offset, int add_buildid) -- cgit v1.2.3 From b06e9318bfd03f531b918bd27b63f1eb88c21729 Mon Sep 17 00:00:00 2001 From: Maninder Singh Date: Thu, 8 Jun 2023 09:01:18 +0530 Subject: kallsyms: move kallsyms_show_value() out of kallsyms.c function kallsyms_show_value() is used by other parts like modules_open(), kprobes_read() etc. which can work in case of !KALLSYMS also. e.g. as of now lsmod do not show module address if KALLSYMS is disabled. since kallsyms_show_value() defination is not present, it returns false in !KALLSYMS. / # lsmod test 12288 0 - Live 0x0000000000000000 (O) So kallsyms_show_value() can be made generic without dependency on KALLSYMS. Thus moving out function to a new file ksyms_common.c. With this patch code is just moved to new file and no functional change. Co-developed-by: Onkarnath Signed-off-by: Onkarnath Signed-off-by: Maninder Singh Reviewed-by: Zhen Lei Signed-off-by: Luis Chamberlain --- kernel/kallsyms.c | 35 ----------------------------------- 1 file changed, 35 deletions(-) (limited to 'kernel/kallsyms.c') diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 8193e947aa10..0f82c3d5a57d 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -907,41 +907,6 @@ late_initcall(bpf_ksym_iter_register); #endif /* CONFIG_BPF_SYSCALL */ -static inline int kallsyms_for_perf(void) -{ -#ifdef CONFIG_PERF_EVENTS - extern int sysctl_perf_event_paranoid; - if (sysctl_perf_event_paranoid <= 1) - return 1; -#endif - return 0; -} - -/* - * We show kallsyms information even to normal users if we've enabled - * kernel profiling and are explicitly not paranoid (so kptr_restrict - * is clear, and sysctl_perf_event_paranoid isn't set). - * - * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to - * block even that). - */ -bool kallsyms_show_value(const struct cred *cred) -{ - switch (kptr_restrict) { - case 0: - if (kallsyms_for_perf()) - return true; - fallthrough; - case 1: - if (security_capable(cred, &init_user_ns, CAP_SYSLOG, - CAP_OPT_NOAUDIT) == 0) - return true; - fallthrough; - default: - return false; - } -} - static int kallsyms_open(struct inode *inode, struct file *file) { /* -- cgit v1.2.3