diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_asm.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_asm.h | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 0c9b5fc4ba0a..352aaebf4198 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -81,12 +81,39 @@ extern u32 __kvm_get_mdcr_el2(void); extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; -/* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */ +/* + * Obtain the PC-relative address of a kernel symbol + * s: symbol + * + * The goal of this macro is to return a symbol's address based on a + * PC-relative computation, as opposed to a loading the VA from a + * constant pool or something similar. This works well for HYP, as an + * absolute VA is guaranteed to be wrong. Only use this if trying to + * obtain the address of a symbol (i.e. not something you obtained by + * following a pointer). + */ +#define hyp_symbol_addr(s) \ + ({ \ + typeof(s) *addr; \ + asm("adrp %0, %1\n" \ + "add %0, %0, :lo12:%1\n" \ + : "=r" (addr) : "S" (&s)); \ + addr; \ + }) + +/* + * Home-grown __this_cpu_{ptr,read} variants that always work at HYP, + * provided that sym is really a *symbol* and not a pointer obtained from + * a data structure. As for SHIFT_PERCPU_PTR(), the creative casting keeps + * sparse quiet. + */ #define __hyp_this_cpu_ptr(sym) \ ({ \ - void *__ptr = hyp_symbol_addr(sym); \ + void *__ptr; \ + __verify_pcpu_ptr(&sym); \ + __ptr = hyp_symbol_addr(sym); \ __ptr += read_sysreg(tpidr_el2); \ - (typeof(&sym))__ptr; \ + (typeof(sym) __kernel __force *)__ptr; \ }) #define __hyp_this_cpu_read(sym) \ |