diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 34 |
1 files changed, 6 insertions, 28 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7bb08670fc10..c2a5a018bd00 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -193,14 +193,6 @@ out: return fault; } -static inline int permission_fault(unsigned int esr) -{ - unsigned int ec = (esr & ESR_ELx_EC_MASK) >> ESR_ELx_EC_SHIFT; - unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; - - return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM); -} - static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, struct pt_regs *regs) { @@ -234,13 +226,12 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, mm_flags |= FAULT_FLAG_WRITE; } - if (permission_fault(esr) && (addr < USER_DS)) { - if (get_fs() == KERNEL_DS) - die("Accessing user space memory with fs=KERNEL_DS", regs, esr); - - if (!search_exception_tables(regs->pc)) - die("Accessing user space memory outside uaccess.h routines", regs, esr); - } + /* + * PAN bit set implies the fault happened in kernel space, but not + * in the arch's user access functions. + */ + if (IS_ENABLED(CONFIG_ARM64_PAN) && (regs->pstate & PSR_PAN_BIT)) + goto no_context; /* * As per x86, we may deadlock here. However, since the kernel only @@ -572,16 +563,3 @@ void cpu_enable_pan(void *__unused) config_sctlr_el1(SCTLR_EL1_SPAN, 0); } #endif /* CONFIG_ARM64_PAN */ - -#ifdef CONFIG_ARM64_UAO -/* - * Kernel threads have fs=KERNEL_DS by default, and don't need to call - * set_fs(), devtmpfs in particular relies on this behaviour. - * We need to enable the feature at runtime (instead of adding it to - * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. - */ -void cpu_enable_uao(void *__unused) -{ - asm(SET_PSTATE_UAO(1)); -} -#endif /* CONFIG_ARM64_UAO */ |