diff options
Diffstat (limited to 'usr/src')
| -rw-r--r-- | usr/src/uts/i86pc/ml/syscall_asm_amd64.s | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/usr/src/uts/i86pc/ml/syscall_asm_amd64.s b/usr/src/uts/i86pc/ml/syscall_asm_amd64.s index fed9afbc8d..882eddc71d 100644 --- a/usr/src/uts/i86pc/ml/syscall_asm_amd64.s +++ b/usr/src/uts/i86pc/ml/syscall_asm_amd64.s @@ -1300,6 +1300,66 @@ _full_syscall_postsys32: SET_SIZE(brand_sys_sysenter) /* + * System call via an int80. This entry point is only used by the Linux + * application environment. Unlike the other entry points, there is no + * default action to take if no callback is registered for this process. + */ + + ENTRY_NP(brand_sys_int80) + SWAPGS /* kernel gsbase */ + XPV_TRAP_POP + call smap_enable + + /* + * We first attempt to call the "b_int80" handler from the "struct + * brand_mach_ops" for this brand. If no handler function is installed + * for this brand, the BRAND_CALLBACK() macro returns here and we + * check the lwp for a "lwp_brand_syscall" handler. + */ + BRAND_CALLBACK(BRAND_CB_INT80, BRAND_URET_FROM_INTR_STACK()) + + /* + * Check to see if this lwp provides "lwp_brand_syscall". If so, we + * will route this int80 through the regular system call handling path. + */ + movq %r15, %gs:CPU_RTMP_R15 + movq %gs:CPU_THREAD, %r15 + movq T_LWP(%r15), %r15 + movq LWP_BRAND_SYSCALL(%r15), %r15 + testq %r15, %r15 + movq %gs:CPU_RTMP_R15, %r15 + jnz nopop_syscall_int + + /* + * The brand provided neither a "b_int80", nor a "lwp_brand_syscall" + * function, and has thus opted out of handling this trap. + */ + SWAPGS /* user gsbase */ + jmp nopop_int80 + + ENTRY_NP(sys_int80) + /* + * We hit an int80, but this process isn't of a brand with an int80 + * handler. Bad process! Make it look as if the INT failed. + * Modify %rip to point before the INT, push the expected error + * code and fake a GP fault. Note on 64-bit hypervisor we need + * to undo the XPV_TRAP_POP and push rcx and r11 back on the stack + * because gptrap will pop them again with its own XPV_TRAP_POP. + */ + XPV_TRAP_POP + call smap_enable +nopop_int80: + subq $2, (%rsp) /* int insn 2-bytes */ + pushq $_CONST(_MUL(T_INT80, GATE_DESC_SIZE) + 2) +#if defined(__xpv) + push %r11 + push %rcx +#endif + jmp gptrap / GP fault + SET_SIZE(sys_int80) + SET_SIZE(brand_sys_int80) + +/* * This is the destination of the "int $T_SYSCALLINT" interrupt gate, used by * the generic i386 libc to do system calls. We do a small amount of setup * before jumping into the existing sys_syscall32 path. |