From f789383fa34a266d0c1a76f272043a15a8edf733 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Thu, 30 Nov 2023 16:39:33 +0100 Subject: [PATCH] x86/ia32: State that IA32 emulation is disabled Issue a short message once, on the first try to load a 32-bit process to save people time when wondering why it won't load and trying to execute it, would say: -bash: ./strsep32: cannot execute binary file: Exec format error Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nikolay Borisov Link: https://lore.kernel.org/r/20231130155213.1407-1-bp@alien8.de --- arch/x86/include/asm/elf.h | 2 +- arch/x86/include/asm/ia32.h | 11 ++++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index a0234dfd1031..1e16bd5ac781 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -150,7 +150,7 @@ do { \ ((x)->e_machine == EM_X86_64) #define compat_elf_check_arch(x) \ - ((elf_check_arch_ia32(x) && ia32_enabled()) || \ + ((elf_check_arch_ia32(x) && ia32_enabled_verbose()) || \ (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64)) static inline void elf_common_init(struct thread_struct *t, diff --git a/arch/x86/include/asm/ia32.h b/arch/x86/include/asm/ia32.h index 5a2ae24b1204..094886a8717e 100644 --- a/arch/x86/include/asm/ia32.h +++ b/arch/x86/include/asm/ia32.h @@ -2,7 +2,6 @@ #ifndef _ASM_X86_IA32_H #define _ASM_X86_IA32_H - #ifdef CONFIG_IA32_EMULATION #include @@ -84,4 +83,14 @@ static inline bool ia32_enabled(void) #endif +static inline bool ia32_enabled_verbose(void) +{ + bool enabled = ia32_enabled(); + + if (IS_ENABLED(CONFIG_IA32_EMULATION) && !enabled) + pr_notice_once("32-bit emulation disabled. You can reenable with ia32_emulation=on\n"); + + return enabled; +} + #endif /* _ASM_X86_IA32_H */