diff options
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 698907724eed..f409b7750114 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -401,6 +401,23 @@ tsk .req x28 // current thread_info .text +#ifdef CONFIG_ARM64_ILP32 +/* + * AARCH64/ILP32. Zero top halves of x0-x7 + * registers as userspace may put garbage there. + */ + .macro delouse_input_regs + mov w0, w0 + mov w1, w1 + mov w2, w2 + mov w3, w3 + mov w4, w4 + mov w5, w5 + mov w6, w6 + mov w7, w7 + .endm +#endif + /* * Exception vectors. */ @@ -695,6 +712,7 @@ el0_svc_compat: */ ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags adrp stbl, compat_sys_call_table // load compat syscall table pointer + ldr x19, [tsk, #TSK_TI_FLAGS] mov wscno, w7 // syscall number in w7 (r7) mov wsc_nr, #__NR_compat_syscalls b el0_svc_naked @@ -916,14 +934,15 @@ ENDPROC(ret_to_user) el0_svc: ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags adrp stbl, sys_call_table // load syscall table pointer + ldr x19, [tsk, #TSK_TI_FLAGS] mov wscno, w8 // syscall number in w8 mov wsc_nr, #__NR_syscalls #ifdef CONFIG_ARM64_SVE alternative_if_not ARM64_SVE - b el0_svc_naked + b el0_svc_select_table alternative_else_nop_endif - tbz x16, #TIF_SVE, el0_svc_naked // Skip unless TIF_SVE set: + tbz x16, #TIF_SVE, el0_svc_select_table // Skip unless TIF_SVE set: bic x16, x16, #_TIF_SVE // discard SVE state str x16, [tsk, #TSK_TI_FLAGS] @@ -939,12 +958,19 @@ alternative_else_nop_endif msr cpacr_el1, x9 // synchronised by eret to el0 #endif +el0_svc_select_table: +#ifdef CONFIG_ARM64_ILP32 + tst x19, #_TIF_32BIT_AARCH64 + b.eq el0_svc_naked // We are using LP64 syscall table + adrp stbl, sys_call_ilp32_table // load ilp32 syscall table pointer + delouse_input_regs +#endif el0_svc_naked: // compat entry point stp x0, xscno, [sp, #S_ORIG_X0] // save the original x0 and syscall number enable_daif ct_user_exit 1 - tst x16, #_TIF_SYSCALL_WORK // check for syscall hooks + tst x19, #_TIF_SYSCALL_WORK // check for syscall hooks b.ne __sys_trace cmp wscno, wsc_nr // check upper syscall limit b.hs ni_sys |