1. 05 4月, 2018 4 次提交
    • D
      syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64 · f8781c4a
      Dominik Brodowski 提交于
      Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting
      ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify
      several codepaths.
      Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f8781c4a
    • D
      syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32 · ebeb8c82
      Dominik Brodowski 提交于
      Extend ARCH_HAS_SYSCALL_WRAPPER for i386 emulation and for x32 on 64-bit
      x86.
      
      For x32, all we need to do is to create an additional stub for each
      compat syscall which decodes the parameters in x86-64 ordering, e.g.:
      
      	asmlinkage long __compat_sys_x32_xyzzy(struct pt_regs *regs)
      	{
      		return c_SyS_xyzzy(regs->di, regs->si, regs->dx);
      	}
      
      For i386 emulation, we need to teach compat_sys_*() to take struct
      pt_regs as its only argument, e.g.:
      
      	asmlinkage long __compat_sys_ia32_xyzzy(struct pt_regs *regs)
      	{
      		return c_SyS_xyzzy(regs->bx, regs->cx, regs->dx);
      	}
      
      In addition, we need to create additional stubs for common syscalls
      (that is, for syscalls which have the same parameters on 32-bit and
      64-bit), e.g.:
      
      	asmlinkage long __sys_ia32_xyzzy(struct pt_regs *regs)
      	{
      		return c_sys_xyzzy(regs->bx, regs->cx, regs->dx);
      	}
      
      This approach avoids leaking random user-provided register content down
      the call chain.
      
      This patch is based on an original proof-of-concept
      
       | From: Linus Torvalds <torvalds@linux-foundation.org>
       | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
      
      and was split up and heavily modified by me, in particular to base it on
      ARCH_HAS_SYSCALL_WRAPPER.
      Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20180405095307.3730-6-linux@dominikbrodowski.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ebeb8c82
    • D
      syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls · fa697140
      Dominik Brodowski 提交于
      Let's make use of ARCH_HAS_SYSCALL_WRAPPER=y on pure 64-bit x86-64 systems:
      
      Each syscall defines a stub which takes struct pt_regs as its only
      argument. It decodes just those parameters it needs, e.g:
      
      	asmlinkage long sys_xyzzy(const struct pt_regs *regs)
      	{
      		return SyS_xyzzy(regs->di, regs->si, regs->dx);
      	}
      
      This approach avoids leaking random user-provided register content down
      the call chain.
      
      For example, for sys_recv() which is a 4-parameter syscall, the assembly
      now is (in slightly reordered fashion):
      
      	<sys_recv>:
      		callq	<__fentry__>
      
      		/* decode regs->di, ->si, ->dx and ->r10 */
      		mov	0x70(%rdi),%rdi
      		mov	0x68(%rdi),%rsi
      		mov	0x60(%rdi),%rdx
      		mov	0x38(%rdi),%rcx
      
      		[ SyS_recv() is automatically inlined by the compiler,
      		  as it is not [yet] used anywhere else ]
      		/* clear %r9 and %r8, the 5th and 6th args */
      		xor	%r9d,%r9d
      		xor	%r8d,%r8d
      
      		/* do the actual work */
      		callq	__sys_recvfrom
      
      		/* cleanup and return */
      		cltq
      		retq
      
      The only valid place in an x86-64 kernel which rightfully calls
      a syscall function on its own -- vsyscall -- needs to be modified
      to pass struct pt_regs onwards as well.
      
      To keep the syscall table generation working independent of
      SYSCALL_PTREGS being enabled, the stubs are named the same as the
      "original" syscall stubs, i.e. sys_*().
      
      This patch is based on an original proof-of-concept
      
       | From: Linus Torvalds <torvalds@linux-foundation.org>
       | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
      
      and was split up and heavily modified by me, in particular to base it on
      ARCH_HAS_SYSCALL_WRAPPER, to limit it to 64-bit-only for the time being,
      and to update the vsyscall to the new calling convention.
      Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20180405095307.3730-4-linux@dominikbrodowski.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fa697140
    • L
      x86/syscalls: Don't pointlessly reload the system call number · dfe64506
      Linus Torvalds 提交于
      We have it in a register in the low-level asm, just pass it in as an
      argument rather than have do_syscall_64() load it back in from the
      ptregs pointer.
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20180405095307.3730-2-linux@dominikbrodowski.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      dfe64506
  2. 03 4月, 2018 19 次提交
  3. 31 3月, 2018 4 次提交
  4. 29 3月, 2018 3 次提交
  5. 28 3月, 2018 4 次提交
  6. 27 3月, 2018 6 次提交
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