From 93d77e7f1410c366050d6035dcba1a5167c7cf0b Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch Date: Fri, 14 Dec 2018 17:05:55 +0100 Subject: ARM: module: Fix function kallsyms on Thumb-2 Thumb-2 functions have the lowest bit set in the symbol value in the symtab. When kallsyms are generated for the vmlinux, the kallsyms are generated from the output of nm, and nm clears the lowest bit. $ arm-linux-gnueabihf-readelf -a vmlinux | grep show_interrupts 95947: 8015dc89 686 FUNC GLOBAL DEFAULT 2 show_interrupts $ arm-linux-gnueabihf-nm vmlinux | grep show_interrupts 8015dc88 T show_interrupts $ cat /proc/kallsyms | grep show_interrupts 8015dc88 T show_interrupts However, for modules, the kallsyms uses the values in the symbol table without modification, so for functions in modules, the lowest bit is set in kallsyms. $ arm-linux-gnueabihf-readelf -a drivers/net/tun.ko | grep tun_get_socket 333: 00002d4d 36 FUNC GLOBAL DEFAULT 1 tun_get_socket $ arm-linux-gnueabihf-nm drivers/net/tun.ko | grep tun_get_socket 00002d4c T tun_get_socket $ cat /proc/kallsyms | grep tun_get_socket 7f802d4d t tun_get_socket [tun] Because of this, the symbol+offset of the crashing instruction shown in oopses is incorrect when the crash is in a module. For example, given a tun_get_socket which starts like this, 00002d4c : 2d4c: 6943 ldr r3, [r0, #20] 2d4e: 4a07 ldr r2, [pc, #28] 2d50: 4293 cmp r3, r2 a crash when tun_get_socket is called with NULL results in: PC is at tun_xdp+0xa3/0xa4 [tun] pc : [<7f802d4c>] As can be seen, the "PC is at" line reports the wrong symbol name, and the symbol+offset will point to the wrong source line if it is passed to gdb. To solve this, add a way for archs to fixup the reading of these module kallsyms values, and use that to clear the lowest bit for function symbols on Thumb-2. After the fix: # cat /proc/kallsyms | grep tun_get_socket 7f802d4c t tun_get_socket [tun] PC is at tun_get_socket+0x0/0x24 [tun] pc : [<7f802d4c>] Signed-off-by: Vincent Whitchurch Signed-off-by: Jessica Yu --- include/linux/module.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index fce6b4335e36..c0b4b7840b57 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -486,6 +486,13 @@ struct module { #define MODULE_ARCH_INIT {} #endif +#ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE +static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym) +{ + return sym->st_value; +} +#endif + extern struct mutex module_mutex; /* FIXME: It'd be nice to isolate modules during init, too, so they -- cgit v1.2.3 From a38d1107f937ca95dcf820161ef44ea683d6a0b1 Mon Sep 17 00:00:00 2001 From: Matt Mullins Date: Wed, 12 Dec 2018 16:42:37 -0800 Subject: bpf: support raw tracepoints in modules Distributions build drivers as modules, including network and filesystem drivers which export numerous tracepoints. This enables bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints. Signed-off-by: Matt Mullins Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- include/linux/module.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index fce6b4335e36..5f147dd5e709 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -432,6 +432,10 @@ struct module { unsigned int num_tracepoints; tracepoint_ptr_t *tracepoints_ptrs; #endif +#ifdef CONFIG_BPF_EVENTS + unsigned int num_bpf_raw_events; + struct bpf_raw_event_map *bpf_raw_events; +#endif #ifdef HAVE_JUMP_LABEL struct jump_entry *jump_entries; unsigned int num_jump_entries; -- cgit v1.2.3 From e9666d10a5677a494260d60d1fa0b73cc7646eb3 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 31 Dec 2018 00:14:15 +0900 Subject: jump_label: move 'asm goto' support test to Kconfig Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Tested-by: Sedat Dilek --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index d5453eb5a68b..9a21fe3509af 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -436,7 +436,7 @@ struct module { unsigned int num_bpf_raw_events; struct bpf_raw_event_map *bpf_raw_events; #endif -#ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_JUMP_LABEL struct jump_entry *jump_entries; unsigned int num_jump_entries; #endif -- cgit v1.2.3 From e4f358916d528d479c3c12bd2fd03f2d5a576380 Mon Sep 17 00:00:00 2001 From: WANG Chao Date: Tue, 11 Dec 2018 00:37:25 +0800 Subject: x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE Commit 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the remaining pieces. [ bp: Massage commit message. ] Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Signed-off-by: WANG Chao Signed-off-by: Borislav Petkov Reviewed-by: Zhenzhong Duan Reviewed-by: Masahiro Yamada Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Daniel Borkmann Cc: David Woodhouse Cc: Geert Uytterhoeven Cc: Jessica Yu Cc: Jiri Kosina Cc: Kees Cook Cc: Konrad Rzeszutek Wilk Cc: Luc Van Oostenryck Cc: Michal Marek Cc: Miguel Ojeda Cc: Peter Zijlstra Cc: Tim Chen Cc: Vasily Gorbik Cc: linux-kbuild@vger.kernel.org Cc: srinivas.eeda@oracle.com Cc: stable Cc: x86-ml Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 9a21fe3509af..8fa38d3e7538 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -828,7 +828,7 @@ static inline void module_bug_finalize(const Elf_Ehdr *hdr, static inline void module_bug_cleanup(struct module *mod) {} #endif /* CONFIG_GENERIC_BUG */ -#ifdef RETPOLINE +#ifdef CONFIG_RETPOLINE extern bool retpoline_module_ok(bool has_retpoline); #else static inline bool retpoline_module_ok(bool has_retpoline) -- cgit v1.2.3