Commit 46eabf06 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar

x86/entry/64: Call all native slow-path syscalls with full pt-regs

This removes all of the remaining asm syscall stubs except for
stub_ptregs_64.  Entries in the main syscall table are now all
callable from C.

The resulting asm is every bit as ridiculous as it looks.  The
next few patches will clean it up.  This patch is here to let
reviewers rest their brains and for bisection.
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a6b3801be0d505d50aefabda02d3b93efbfc9c73.1454022279.git.luto@kernel.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 302f5b26
...@@ -253,7 +253,6 @@ tracesys: ...@@ -253,7 +253,6 @@ tracesys:
* the value it wants us to use in the table lookup. * the value it wants us to use in the table lookup.
*/ */
RESTORE_C_REGS_EXCEPT_RAX RESTORE_C_REGS_EXCEPT_RAX
RESTORE_EXTRA_REGS
#if __SYSCALL_MASK == ~0 #if __SYSCALL_MASK == ~0
cmpq $__NR_syscall_max, %rax cmpq $__NR_syscall_max, %rax
#else #else
...@@ -264,6 +263,7 @@ tracesys: ...@@ -264,6 +263,7 @@ tracesys:
movq %r10, %rcx /* fixup for C */ movq %r10, %rcx /* fixup for C */
call *sys_call_table(, %rax, 8) call *sys_call_table(, %rax, 8)
movq %rax, RAX(%rsp) movq %rax, RAX(%rsp)
RESTORE_EXTRA_REGS
1: 1:
/* Use IRET because user could have changed pt_regs->foo */ /* Use IRET because user could have changed pt_regs->foo */
...@@ -384,83 +384,6 @@ END(ptregs_\func) ...@@ -384,83 +384,6 @@ END(ptregs_\func)
#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym) #define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
#include <asm/syscalls_64.h> #include <asm/syscalls_64.h>
.macro FORK_LIKE func
ENTRY(stub_\func)
SAVE_EXTRA_REGS 8
jmp sys_\func
END(stub_\func)
.endm
FORK_LIKE clone
FORK_LIKE fork
FORK_LIKE vfork
ENTRY(stub_execve)
call sys_execve
return_from_execve:
testl %eax, %eax
jz 1f
/* exec failed, can use fast SYSRET code path in this case */
ret
1:
/* must use IRET code path (pt_regs->cs may have changed) */
addq $8, %rsp
ZERO_EXTRA_REGS
movq %rax, RAX(%rsp)
jmp int_ret_from_sys_call
END(stub_execve)
/*
* Remaining execve stubs are only 7 bytes long.
* ENTRY() often aligns to 16 bytes, which in this case has no benefits.
*/
.align 8
GLOBAL(stub_execveat)
call sys_execveat
jmp return_from_execve
END(stub_execveat)
#if defined(CONFIG_X86_X32_ABI)
.align 8
GLOBAL(stub_x32_execve)
call compat_sys_execve
jmp return_from_execve
END(stub_x32_execve)
.align 8
GLOBAL(stub_x32_execveat)
call compat_sys_execveat
jmp return_from_execve
END(stub_x32_execveat)
#endif
/*
* sigreturn is special because it needs to restore all registers on return.
* This cannot be done with SYSRET, so use the IRET return path instead.
*/
ENTRY(stub_rt_sigreturn)
/*
* SAVE_EXTRA_REGS result is not normally needed:
* sigreturn overwrites all pt_regs->GPREGS.
* But sigreturn can fail (!), and there is no easy way to detect that.
* To make sure RESTORE_EXTRA_REGS doesn't restore garbage on error,
* we SAVE_EXTRA_REGS here.
*/
SAVE_EXTRA_REGS 8
call sys_rt_sigreturn
return_from_stub:
addq $8, %rsp
RESTORE_EXTRA_REGS
movq %rax, RAX(%rsp)
jmp int_ret_from_sys_call
END(stub_rt_sigreturn)
#ifdef CONFIG_X86_X32_ABI
ENTRY(stub_x32_rt_sigreturn)
SAVE_EXTRA_REGS 8
call sys32_x32_rt_sigreturn
jmp return_from_stub
END(stub_x32_rt_sigreturn)
#endif
/* /*
* A newly forked process directly context switches into this address. * A newly forked process directly context switches into this address.
* *
......
...@@ -21,7 +21,7 @@ ...@@ -21,7 +21,7 @@
12 common brk sys_brk 12 common brk sys_brk
13 64 rt_sigaction sys_rt_sigaction 13 64 rt_sigaction sys_rt_sigaction
14 common rt_sigprocmask sys_rt_sigprocmask 14 common rt_sigprocmask sys_rt_sigprocmask
15 64 rt_sigreturn stub_rt_sigreturn/ptregs 15 64 rt_sigreturn sys_rt_sigreturn/ptregs
16 64 ioctl sys_ioctl 16 64 ioctl sys_ioctl
17 common pread64 sys_pread64 17 common pread64 sys_pread64
18 common pwrite64 sys_pwrite64 18 common pwrite64 sys_pwrite64
...@@ -62,10 +62,10 @@ ...@@ -62,10 +62,10 @@
53 common socketpair sys_socketpair 53 common socketpair sys_socketpair
54 64 setsockopt sys_setsockopt 54 64 setsockopt sys_setsockopt
55 64 getsockopt sys_getsockopt 55 64 getsockopt sys_getsockopt
56 common clone stub_clone/ptregs 56 common clone sys_clone/ptregs
57 common fork stub_fork/ptregs 57 common fork sys_fork/ptregs
58 common vfork stub_vfork/ptregs 58 common vfork sys_vfork/ptregs
59 64 execve stub_execve/ptregs 59 64 execve sys_execve/ptregs
60 common exit sys_exit 60 common exit sys_exit
61 common wait4 sys_wait4 61 common wait4 sys_wait4
62 common kill sys_kill 62 common kill sys_kill
...@@ -328,7 +328,7 @@ ...@@ -328,7 +328,7 @@
319 common memfd_create sys_memfd_create 319 common memfd_create sys_memfd_create
320 common kexec_file_load sys_kexec_file_load 320 common kexec_file_load sys_kexec_file_load
321 common bpf sys_bpf 321 common bpf sys_bpf
322 64 execveat stub_execveat/ptregs 322 64 execveat sys_execveat/ptregs
323 common userfaultfd sys_userfaultfd 323 common userfaultfd sys_userfaultfd
324 common membarrier sys_membarrier 324 common membarrier sys_membarrier
325 common mlock2 sys_mlock2 325 common mlock2 sys_mlock2
...@@ -339,14 +339,14 @@ ...@@ -339,14 +339,14 @@
# for native 64-bit operation. # for native 64-bit operation.
# #
512 x32 rt_sigaction compat_sys_rt_sigaction 512 x32 rt_sigaction compat_sys_rt_sigaction
513 x32 rt_sigreturn stub_x32_rt_sigreturn 513 x32 rt_sigreturn sys32_x32_rt_sigreturn
514 x32 ioctl compat_sys_ioctl 514 x32 ioctl compat_sys_ioctl
515 x32 readv compat_sys_readv 515 x32 readv compat_sys_readv
516 x32 writev compat_sys_writev 516 x32 writev compat_sys_writev
517 x32 recvfrom compat_sys_recvfrom 517 x32 recvfrom compat_sys_recvfrom
518 x32 sendmsg compat_sys_sendmsg 518 x32 sendmsg compat_sys_sendmsg
519 x32 recvmsg compat_sys_recvmsg 519 x32 recvmsg compat_sys_recvmsg
520 x32 execve stub_x32_execve/ptregs 520 x32 execve compat_sys_execve/ptregs
521 x32 ptrace compat_sys_ptrace 521 x32 ptrace compat_sys_ptrace
522 x32 rt_sigpending compat_sys_rt_sigpending 522 x32 rt_sigpending compat_sys_rt_sigpending
523 x32 rt_sigtimedwait compat_sys_rt_sigtimedwait 523 x32 rt_sigtimedwait compat_sys_rt_sigtimedwait
...@@ -371,4 +371,4 @@ ...@@ -371,4 +371,4 @@
542 x32 getsockopt compat_sys_getsockopt 542 x32 getsockopt compat_sys_getsockopt
543 x32 io_setup compat_sys_io_setup 543 x32 io_setup compat_sys_io_setup
544 x32 io_submit compat_sys_io_submit 544 x32 io_submit compat_sys_io_submit
545 x32 execveat stub_x32_execveat/ptregs 545 x32 execveat compat_sys_execveat/ptregs
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