diff options
| -rw-r--r-- | arch/x86/entry/entry_64.S | 56 | ||||
| -rw-r--r-- | arch/x86/entry/syscall_64.c | 7 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 16 |
3 files changed, 55 insertions, 24 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 9d34d3c..f1c8f15 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -182,7 +182,15 @@ entry_SYSCALL_64_fastpath: #endif ja 1f /* return -ENOSYS (already in pt_regs->ax) */ movq %r10, %rcx + + /* + * This call instruction is handled specially in stub_ptregs_64. + * It might end up jumping to the slow path. If it jumps, RAX is + * clobbered. + */ call *sys_call_table(, %rax, 8) +.Lentry_SYSCALL_64_after_fastpath_call: + movq %rax, RAX(%rsp) 1: /* @@ -235,25 +243,13 @@ GLOBAL(int_ret_from_sys_call_irqs_off) /* Do syscall entry tracing */ tracesys: - movq %rsp, %rdi - movl $AUDIT_ARCH_X86_64, %esi - call syscall_trace_enter_phase1 - test %rax, %rax - jnz tracesys_phase2 /* if needed, run the slow path */ - RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */ - movq ORIG_RAX(%rsp), %rax - jmp entry_SYSCALL_64_fastpath /* and return to the fast path */ - -tracesys_phase2: SAVE_EXTRA_REGS movq %rsp, %rdi - movl $AUDIT_ARCH_X86_64, %esi - movq %rax, %rdx - call syscall_trace_enter_phase2 + call syscall_trace_enter /* * Reload registers from stack in case ptrace changed them. - * We don't reload %rax because syscall_trace_entry_phase2() returned + * We don't reload %rax because syscall_trace_enter() returned * the value it wants us to use in the table lookup. */ RESTORE_C_REGS_EXCEPT_RAX @@ -355,6 +351,38 @@ opportunistic_sysret_failed: jmp restore_c_regs_and_iret END(entry_SYSCALL_64) +ENTRY(stub_ptregs_64) + /* + * Syscalls marked as needing ptregs land here. + * If we are on the fast path, we need to save the extra regs. + * If we are on the slow path, the extra regs are already saved. + * + * RAX stores a pointer to the C function implementing the syscall. + */ + cmpq $.Lentry_SYSCALL_64_after_fastpath_call, (%rsp) + jne 1f + + /* Called from fast path -- pop return address and jump to slow path */ + popq %rax + jmp tracesys /* called from fast path */ + +1: + /* Called from C */ + jmp *%rax /* called from C */ +END(stub_ptregs_64) + +.macro ptregs_stub func +ENTRY(ptregs_\func) + leaq \func(%rip), %rax + jmp stub_ptregs_64 +END(ptregs_\func) +.endm + +/* Instantiate ptregs_stub for each ptregs-using syscall */ +#define __SYSCALL_64_QUAL_(sym) +#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_stub sym +#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym) +#include <asm/syscalls_64.h> .macro FORK_LIKE func ENTRY(stub_\func) diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c index a1d4087..9dbc5ab 100644 --- a/arch/x86/entry/syscall_64.c +++ b/arch/x86/entry/syscall_64.c @@ -6,11 +6,14 @@ #include <asm/asm-offsets.h> #include <asm/syscall.h> -#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ; +#define __SYSCALL_64_QUAL_(sym) sym +#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_##sym + +#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long __SYSCALL_64_QUAL_##qual(sym)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); #include <asm/syscalls_64.h> #undef __SYSCALL_64 -#define __SYSCALL_64(nr, sym, qual) [nr] = sym, +#define __SYSCALL_64(nr, sym, qual) [nr] = __SYSCALL_64_QUAL_##qual(sym), extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index dc1040a..5de342a 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -21,7 +21,7 @@ 12 common brk sys_brk 13 64 rt_sigaction sys_rt_sigaction 14 common rt_sigprocmask sys_rt_sigprocmask -15 64 rt_sigreturn stub_rt_sigreturn +15 64 rt_sigreturn stub_rt_sigreturn/ptregs 16 64 ioctl sys_ioctl 17 common pread64 sys_pread64 18 common pwrite64 sys_pwrite64 @@ -62,10 +62,10 @@ 53 common socketpair sys_socketpair 54 64 setsockopt sys_setsockopt 55 64 getsockopt sys_getsockopt -56 common clone stub_clone -57 common fork stub_fork -58 common vfork stub_vfork -59 64 execve stub_execve +56 common clone stub_clone/ptregs +57 common fork stub_fork/ptregs +58 common vfork stub_vfork/ptregs +59 64 execve stub_execve/ptregs 60 common exit sys_exit 61 common wait4 sys_wait4 62 common kill sys_kill @@ -328,7 +328,7 @@ 319 common memfd_create sys_memfd_create 320 common kexec_file_load sys_kexec_file_load 321 common bpf sys_bpf -322 64 execveat stub_execveat +322 64 execveat stub_execveat/ptregs 323 common userfaultfd sys_userfaultfd 324 common membarrier sys_membarrier 325 common mlock2 sys_mlock2 @@ -346,7 +346,7 @@ 517 x32 recvfrom compat_sys_recvfrom 518 x32 sendmsg compat_sys_sendmsg 519 x32 recvmsg compat_sys_recvmsg -520 x32 execve stub_x32_execve +520 x32 execve stub_x32_execve/ptregs 521 x32 ptrace compat_sys_ptrace 522 x32 rt_sigpending compat_sys_rt_sigpending 523 x32 rt_sigtimedwait compat_sys_rt_sigtimedwait @@ -371,4 +371,4 @@ 542 x32 getsockopt compat_sys_getsockopt 543 x32 io_setup compat_sys_io_setup 544 x32 io_submit compat_sys_io_submit -545 x32 execveat stub_x32_execveat +545 x32 execveat stub_x32_execveat/ptregs |