From eebadafc3b14d9426fa9cc3ab0da0e48367c7114 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 15 May 2024 15:03:35 +0100 Subject: ARM: 9398/1: Fix userspace enter on LPAE with CC_OPTIMIZE_FOR_SIZE=y Booting an LPAE-enabled kernel built with CONFIG_CC_OPTIMIZE_FOR_SIZE=y fails when starting userspace: Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 CPU: 1 PID: 1 Comm: init Tainted: G W N 6.9.0-rc1-koelsch-00004-g7af5b901e847 #1930 Hardware name: Generic R-Car Gen2 (Flattened Device Tree) Call trace: unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x78/0xa8 dump_stack_lvl from panic+0x118/0x398 panic from do_exit+0x1ec/0x938 do_exit from sys_exit_group+0x0/0x10 ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004 ]--- Add the missing memory clobber to cpu_set_ttbcr(), as suggested by Russell King. Force inlining of uaccess_save_and_enable(), as suggested by Ard Biesheuvel. The latter fixes booting on Koelsch. Closes: https://lore.kernel.org/r/CAMuHMdWTAJcZ9BReWNhpmsgkOzQxLNb5OhNYxzxv6D5TSh2fwQ@mail.gmail.com/ Fixes: 7af5b901e84743c6 ("ARM: 9358/2: Implement PAN for LPAE by TTBR0 page table walks disablement") Acked-by: Ard Biesheuvel Reviewed-by: Linus Walleij Tested-by: Florian Fainelli Signed-off-by: Geert Uytterhoeven Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/proc-fns.h | 2 +- arch/arm/include/asm/uaccess.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h index 9b3105a2a5e0..b4986a23d852 100644 --- a/arch/arm/include/asm/proc-fns.h +++ b/arch/arm/include/asm/proc-fns.h @@ -187,7 +187,7 @@ static inline unsigned int cpu_get_ttbcr(void) static inline void cpu_set_ttbcr(unsigned int ttbcr) { - asm("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr)); + asm volatile("mcr p15, 0, %0, c2, c0, 2" : : "r" (ttbcr) : "memory"); } #else /*!CONFIG_MMU */ diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 25d21d7d6e3e..6c9c16d767cf 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -47,7 +47,7 @@ static __always_inline void uaccess_restore(unsigned int flags) #elif defined(CONFIG_CPU_TTBR0_PAN) -static inline unsigned int uaccess_save_and_enable(void) +static __always_inline unsigned int uaccess_save_and_enable(void) { unsigned int old_ttbcr = cpu_get_ttbcr(); -- cgit v1.2.3