linux-dev/arch/x86/entry/syscall_32.c, branch linus/master

x86/syscalls: Stop filling syscall arrays with *_sys_ni_syscall

2021-05-20T13:03:59Z

This is a follow-up cleanup after switching to the generic syscalltbl.sh. The old x86 specific script skipped non-existing syscalls. So, the generated syscalls_64.h, for example, had a big hole in the syscall numbers 335-423 range. That is why there exists [0 ... __NR_*_syscall_max] = &__*_sys_ni_cyscall. The new script, scripts/syscalltbl.sh automatically fills holes with __SYSCALL(, sys_ni_syscall), hence such ugly code can go away. The designated initializers, '[nr] =' are also unneeded. Also, there is no need to give __NR_*_syscall_max+1 because the array size is implied by the number of syscalls in the generated headers. Hence, there is no need to include , either. Signed-off-by: Masahiro Yamada Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210517073815.97426-4-masahiroy@kernel.org

x86/syscalls: Switch to generic syscalltbl.sh

2021-05-20T13:03:58Z

Many architectures duplicate similar shell scripts. Convert x86 and UML to use scripts/syscalltbl.sh. The generic script generates seperate headers for x86/64 and x86/x32 syscalls, while the x86 specific script coalesced them into one. Adjust the code accordingly. Signed-off-by: Masahiro Yamada Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210517073815.97426-3-masahiroy@kernel.org

x86/entry: Drop asmlinkage from syscalls

2020-03-21T15:03:25Z

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 Signed-off-by: Thomas Gleixner Reviewed-by: Dominik Brodowski Reviewed-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20200313195144.164260-18-brgerst@gmail.com

x86/entry/32: Enable pt_regs based syscalls

2020-03-21T15:03:24Z

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 Signed-off-by: Thomas Gleixner Reviewed-by: Dominik Brodowski Link: https://lkml.kernel.org/r/20200313195144.164260-17-brgerst@gmail.com

x86/entry: Remove ABI prefixes from functions in syscall tables

2020-03-21T15:03:23Z

Move the ABI prefixes to the __SYSCALL_[abi]() macros. This allows removal of the need to strip the prefix for UML. Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200313195144.164260-13-brgerst@gmail.com

x86/entry: Remove syscall qualifier support

2020-03-21T15:03:22Z

Syscall qualifier support is no longer needed. Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Reviewed-by: Dominik Brodowski Link: https://lkml.kernel.org/r/20200313195144.164260-11-brgerst@gmail.com

x86/entry: Move max syscall number calculation to syscallhdr.sh

2020-03-21T15:03:21Z

Instead of using an array in asm-offsets to calculate the max syscall number, calculate it when writing out the syscall headers. Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200313195144.164260-9-brgerst@gmail.com

syscalls/x86: Use the correct function type for sys_ni_syscall

2019-10-11T10:49:18Z

Use the correct function type for sys_ni_syscall() in system call tables to fix indirect call mismatches with Control-Flow Integrity (CFI) checking. Signed-off-by: Sami Tolvanen Acked-by: Andy Lutomirski Cc: Borislav Petkov Cc: H . Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20191008224049.115427-5-samitolvanen@google.com Signed-off-by: Ingo Molnar

syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64

2018-04-05T14:59:38Z

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: Dominik Brodowski Acked-by: Linus Torvalds Cc: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar

syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32

2018-04-05T14:59:38Z

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 | Signed-off-by: Linus Torvalds and was split up and heavily modified by me, in particular to base it on ARCH_HAS_SYSCALL_WRAPPER. Signed-off-by: Dominik Brodowski Acked-by: Linus Torvalds Cc: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180405095307.3730-6-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar