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* x86/entry: Fix build error x86 with !CONFIG_POSIX_TIMERSBrian Gerst2020-03-251-1/+1
| | | | | | | | | | | Add missing semicolon. Fixes: a74d187c2df3 ("x86/entry: Refactor SYS_NI macros") Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200324143520.898733-1-brgerst@gmail.com
* x86/entry: Drop asmlinkage from syscallsBrian Gerst2020-03-211-17/+14
| | | | | | | | | | | | | asmlinkage is no longer required since the syscall ABI is now fully under x86 architecture control. This makes the 32-bit native syscalls a bit more effecient by passing in regs via EAX instead of on the stack. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-18-brgerst@gmail.com
* x86/entry/32: Enable pt_regs based syscallsBrian Gerst2020-03-211-50/+61
| | | | | | | | | | | | Enable pt_regs based syscalls for 32-bit. This makes the 32-bit native kernel consistent with the 64-bit kernel, and improves the syscall interface by not needing to push all 6 potential arguments onto the stack. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://lkml.kernel.org/r/20200313195144.164260-17-brgerst@gmail.com
* x86/entry/64: Move sys_ni_syscall stub to common.cBrian Gerst2020-03-211-0/+3
| | | | | | | | | | so it can be available to multiple syscall tables. Also directly return -ENOSYS instead of bouncing to the generic sys_ni_syscall(). Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-7-brgerst@gmail.com
* x86/entry: Refactor SYS_NI macrosBrian Gerst2020-03-211-9/+23
| | | | | | | | | | | | | Pull the common code out from the SYS_NI macros into a new __SYS_NI macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-5-brgerst@gmail.com
* x86/entry: Refactor COND_SYSCALL macrosBrian Gerst2020-03-211-18/+26
| | | | | | | | | | | | | Pull the common code out from the COND_SYSCALL macros into a new __COND_SYSCALL macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-4-brgerst@gmail.com
* x86/entry: Refactor SYSCALL_DEFINE0 macrosBrian Gerst2020-03-211-41/+32
| | | | | | | | | | | | | Pull the common code out from the SYSCALL_DEFINE0 macros into a new __SYS_STUB0 macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-3-brgerst@gmail.com
* x86/entry: Refactor SYSCALL_DEFINEx macrosBrian Gerst2020-03-211-25/+24
| | | | | | | | | | | | | Pull the common code out from the SYSCALL_DEFINEx macros into a new __SYS_STUBx macro. Also conditionalize the X64 version in preparation for enabling syscall wrappers on 32-bit native kernels. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-2-brgerst@gmail.com
* syscalls/x86: Fix function types in COND_SYSCALLSami Tolvanen2019-10-111-5/+16
| | | | | | | | | | | | | | | | | Define a weak function in COND_SYSCALL instead of a weak alias to sys_ni_syscall(), which has an incompatible type. This fixes indirect call mismatches with Control-Flow Integrity (CFI) checking. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H . Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191008224049.115427-6-samitolvanen@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Wire up COMPAT_SYSCALL_DEFINE0Andy Lutomirski2019-10-111-2/+30
| | | | | | | | | | | | | | | | | x86 has special handling for COMPAT_SYSCALL_DEFINEx, but there was no override for COMPAT_SYSCALL_DEFINE0. Wire it up so that we can use it for rt_sigreturn. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H . Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191008224049.115427-3-samitolvanen@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Use the correct function type in SYSCALL_DEFINE0Sami Tolvanen2019-10-111-11/+12
| | | | | | | | | | | | | | | | | Although a syscall defined using SYSCALL_DEFINE0 doesn't accept parameters, use the correct function type to avoid type mismatches with Control-Flow Integrity (CFI) checking. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H . Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191008224049.115427-2-samitolvanen@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming conventionDominik Brodowski2018-04-091-9/+9
| | | | | | | | | | | | | | | | | | | | Make the code in syscall_wrapper.h more readable by naming the stub macros similar to the stub they provide. While at it, fix a stray newline at the end of the __IA32_COMPAT_SYS_STUBx macro. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> 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: Josh Poimboeuf <jpoimboe@redhat.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/20180409105145.5364-5-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to ↵Dominik Brodowski2018-04-091-17/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __x64_sys_*() This rename allows us to have a coherent syscall stub naming convention on 64-bit x86 (0xffffffff prefix removed): 810f0af0 t kernel_waitid # common (32/64) kernel helper <inline> __do_sys_waitid # inlined helper doing actual work 810f0be0 t __se_sys_waitid # C func calling inlined helper <inline> __do_compat_sys_waitid # inlined helper doing actual work 810f0d80 t __se_compat_sys_waitid # compat C func calling inlined helper 810f2080 T __x64_sys_waitid # x64 64-bit-ptregs -> C stub 810f20b0 T __ia32_sys_waitid # ia32 32-bit-ptregs -> C stub[*] 810f2470 T __ia32_compat_sys_waitid # ia32 32-bit-ptregs -> compat C stub 810f2490 T __x32_compat_sys_waitid # x32 64-bit-ptregs -> compat C stub [*] This stub is unused, as the syscall table links __ia32_compat_sys_waitid instead of __ia32_sys_waitid as we need a compat variant here. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> 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: Josh Poimboeuf <jpoimboe@redhat.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/20180409105145.5364-4-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/core, syscalls/x86: Clean up compat syscall stub naming conventionDominik Brodowski2018-04-091-22/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tidy the naming convention for compat syscall subs. Hints which describe the purpose of the stub go in front and receive a double underscore to denote that they are generated on-the-fly by the COMPAT_SYSCALL_DEFINEx() macro. For the generic case, this means: t kernel_waitid # common C function (see kernel/exit.c) __do_compat_sys_waitid # inlined helper doing the actual work # (takes original parameters as declared) T __se_compat_sys_waitid # sign-extending C function calling inlined # helper (takes parameters of type long, # casts them to unsigned long and then to # the declared type) T compat_sys_waitid # alias to __se_compat_sys_waitid() # (taking parameters as declared), to # be included in syscall table For x86, the naming is as follows: t kernel_waitid # common C function (see kernel/exit.c) __do_compat_sys_waitid # inlined helper doing the actual work # (takes original parameters as declared) t __se_compat_sys_waitid # sign-extending C function calling inlined # helper (takes parameters of type long, # casts them to unsigned long and then to # the declared type) T __ia32_compat_sys_waitid # IA32_EMULATION 32-bit-ptregs -> C stub, # calls __se_compat_sys_waitid(); to be # included in syscall table T __x32_compat_sys_waitid # x32 64-bit-ptregs -> C stub, calls # __se_compat_sys_waitid(); to be included # in syscall table If only one of IA32_EMULATION and x32 is enabled, __se_compat_sys_waitid() may be inlined into the stub __{ia32,x32}_compat_sys_waitid(). Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> 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: Josh Poimboeuf <jpoimboe@redhat.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/20180409105145.5364-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/core, syscalls/x86: Clean up syscall stub naming conventionDominik Brodowski2018-04-091-17/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tidy the naming convention for compat syscall subs. Hints which describe the purpose of the stub go in front and receive a double underscore to denote that they are generated on-the-fly by the SYSCALL_DEFINEx() macro. For the generic case, this means (0xffffffff prefix removed): 810f08d0 t kernel_waitid # common C function (see kernel/exit.c) <inline> __do_sys_waitid # inlined helper doing the actual work # (takes original parameters as declared) 810f1aa0 T __se_sys_waitid # sign-extending C function calling inlined # helper (takes parameters of type long; # casts them to the declared type) 810f1aa0 T sys_waitid # alias to __se_sys_waitid() (taking # parameters as declared), to be included # in syscall table For x86, the naming is as follows: 810efc70 t kernel_waitid # common C function (see kernel/exit.c) <inline> __do_sys_waitid # inlined helper doing the actual work # (takes original parameters as declared) 810efd60 t __se_sys_waitid # sign-extending C function calling inlined # helper (takes parameters of type long; # casts them to the declared type) 810f1140 T __ia32_sys_waitid # IA32_EMULATION 32-bit-ptregs -> C stub, # calls __se_sys_waitid(); to be included # in syscall table 810f1110 T sys_waitid # x86 64-bit-ptregs -> C stub, calls # __se_sys_waitid(); to be included in # syscall table For x86, sys_waitid() will be re-named to __x64_sys_waitid in a follow-up patch. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> 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: Josh Poimboeuf <jpoimboe@redhat.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/20180409105145.5364-2-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION ↵Dominik Brodowski2018-04-051-4/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and x32 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: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus 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.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Use 'struct pt_regs' based syscall calling convention for ↵Dominik Brodowski2018-04-051-0/+70
64-bit syscalls 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: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus 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.net Signed-off-by: Ingo Molnar <mingo@kernel.org>