privcmd_call requires to enable access to userspace for the duration of the hypercall.
Currently, this is done via assembly macros. Change it to C inlines instead. Signed-off-by: Pavel Tatashin <pasha.tatas...@soleen.com> Acked-by: Stefano Stabellini <sstabell...@kernel.org> --- arch/arm/include/asm/assembler.h | 2 +- arch/arm/include/asm/xen/hypercall.h | 10 +++++++++ arch/arm/xen/enlighten.c | 2 +- arch/arm/xen/hypercall.S | 4 ++-- arch/arm64/include/asm/xen/hypercall.h | 28 ++++++++++++++++++++++++++ arch/arm64/xen/hypercall.S | 19 ++--------------- include/xen/arm/hypercall.h | 12 +++++------ 7 files changed, 50 insertions(+), 27 deletions(-) diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 99929122dad7..8e9262a0f016 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -480,7 +480,7 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) .macro uaccess_disable, tmp, isb=1 #ifdef CONFIG_CPU_SW_DOMAIN_PAN /* - * Whenever we re-enter userspace, the domains should always be + * Whenever we re-enter kernel, the domains should always be * set appropriately. */ mov \tmp, #DACR_UACCESS_DISABLE diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h index 3522cbaed316..cac5bd9ef519 100644 --- a/arch/arm/include/asm/xen/hypercall.h +++ b/arch/arm/include/asm/xen/hypercall.h @@ -1 +1,11 @@ +#ifndef _ASM_ARM_XEN_HYPERCALL_H +#define _ASM_ARM_XEN_HYPERCALL_H #include <xen/arm/hypercall.h> + +static inline long privcmd_call(unsigned int call, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5) +{ + return arch_privcmd_call(call, a1, a2, a3, a4, a5); +} +#endif /* _ASM_ARM_XEN_HYPERCALL_H */ diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index dd6804a64f1a..e87280c6d25d 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -440,4 +440,4 @@ EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op_raw); EXPORT_SYMBOL_GPL(HYPERVISOR_multicall); EXPORT_SYMBOL_GPL(HYPERVISOR_vm_assist); EXPORT_SYMBOL_GPL(HYPERVISOR_dm_op); -EXPORT_SYMBOL_GPL(privcmd_call); +EXPORT_SYMBOL_GPL(arch_privcmd_call); diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S index b11bba542fac..277078c7da49 100644 --- a/arch/arm/xen/hypercall.S +++ b/arch/arm/xen/hypercall.S @@ -94,7 +94,7 @@ HYPERCALL2(multicall); HYPERCALL2(vm_assist); HYPERCALL3(dm_op); -ENTRY(privcmd_call) +ENTRY(arch_privcmd_call) stmdb sp!, {r4} mov r12, r0 mov r0, r1 @@ -119,4 +119,4 @@ ENTRY(privcmd_call) ldm sp!, {r4} ret lr -ENDPROC(privcmd_call); +ENDPROC(arch_privcmd_call); diff --git a/arch/arm64/include/asm/xen/hypercall.h b/arch/arm64/include/asm/xen/hypercall.h index 3522cbaed316..1a74fb28607f 100644 --- a/arch/arm64/include/asm/xen/hypercall.h +++ b/arch/arm64/include/asm/xen/hypercall.h @@ -1 +1,29 @@ +#ifndef _ASM_ARM64_XEN_HYPERCALL_H +#define _ASM_ARM64_XEN_HYPERCALL_H #include <xen/arm/hypercall.h> +#include <linux/uaccess.h> + +static inline long privcmd_call(unsigned int call, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5) +{ + long rv; + + /* + * Privcmd calls are issued by the userspace. The kernel needs to + * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 + * translations to user memory via AT instructions. Since AT + * instructions are not affected by the PAN bit (ARMv8.1), we only + * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation + * is enabled (it implies that hardware UAO and PAN disabled). + */ + uaccess_ttbr0_enable(); + rv = arch_privcmd_call(call, a1, a2, a3, a4, a5); + /* + * Disable userspace access from kernel once the hyp call completed. + */ + uaccess_ttbr0_disable(); + + return rv; +} +#endif /* _ASM_ARM64_XEN_HYPERCALL_H */ diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S index c5f05c4a4d00..921611778d2a 100644 --- a/arch/arm64/xen/hypercall.S +++ b/arch/arm64/xen/hypercall.S @@ -49,7 +49,6 @@ #include <linux/linkage.h> #include <asm/assembler.h> -#include <asm/asm-uaccess.h> #include <xen/interface/xen.h> @@ -86,27 +85,13 @@ HYPERCALL2(multicall); HYPERCALL2(vm_assist); HYPERCALL3(dm_op); -ENTRY(privcmd_call) +ENTRY(arch_privcmd_call) mov x16, x0 mov x0, x1 mov x1, x2 mov x2, x3 mov x3, x4 mov x4, x5 - /* - * Privcmd calls are issued by the userspace. The kernel needs to - * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 - * translations to user memory via AT instructions. Since AT - * instructions are not affected by the PAN bit (ARMv8.1), we only - * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation - * is enabled (it implies that hardware UAO and PAN disabled). - */ - uaccess_ttbr0_enable x6, x7, x8 hvc XEN_IMM - - /* - * Disable userspace access from kernel once the hyp call completed. - */ - uaccess_ttbr0_disable x6, x7 ret -ENDPROC(privcmd_call); +ENDPROC(arch_privcmd_call); diff --git a/include/xen/arm/hypercall.h b/include/xen/arm/hypercall.h index b40485e54d80..624c8ad7e42a 100644 --- a/include/xen/arm/hypercall.h +++ b/include/xen/arm/hypercall.h @@ -30,8 +30,8 @@ * IN THE SOFTWARE. */ -#ifndef _ASM_ARM_XEN_HYPERCALL_H -#define _ASM_ARM_XEN_HYPERCALL_H +#ifndef _ARM_XEN_HYPERCALL_H +#define _ARM_XEN_HYPERCALL_H #include <linux/bug.h> @@ -41,9 +41,9 @@ struct xen_dm_op_buf; -long privcmd_call(unsigned call, unsigned long a1, - unsigned long a2, unsigned long a3, - unsigned long a4, unsigned long a5); +long arch_privcmd_call(unsigned int call, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5); int HYPERVISOR_xen_version(int cmd, void *arg); int HYPERVISOR_console_io(int cmd, int count, char *str); int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count); @@ -88,4 +88,4 @@ MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req, BUG(); } -#endif /* _ASM_ARM_XEN_HYPERCALL_H */ +#endif /* _ARM_XEN_HYPERCALL_H */ -- 2.24.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel