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path: root/arch/x86/entry/syscall_x32.c
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2024-04-08x86/syscall: Don't force use of indirect calls for system callsLinus Torvalds1-3/+7
Make <asm/syscall.h> build a switch statement instead, and the compiler can either decide to generate an indirect jump, or - more likely these days due to mitigations - just a series of conditional branches. Yes, the conditional branches also have branch prediction, but the branch prediction is much more controlled, in that it just causes speculatively running the wrong system call (harmless), rather than speculatively running possibly wrong random less controlled code gadgets. This doesn't mitigate other indirect calls, but the system call indirection is the first and most easily triggered case. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2021-05-20x86/syscalls: Stop filling syscall arrays with *_sys_ni_syscallMasahiro Yamada1-8/+2
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(<nr>, 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 <asm/unistd.h>, either. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210517073815.97426-4-masahiroy@kernel.org
2021-05-20x86/syscalls: Switch to generic syscalltbl.shMasahiro Yamada1-10/+5
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 <masahiroy@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210517073815.97426-3-masahiroy@kernel.org
2021-05-20x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_*Masahiro Yamada1-14/+2
The SYSCALL macros are mapped to symbols as follows: __SYSCALL_COMMON(nr, sym) --> __x64_<sym> __SYSCALL_X32(nr, sym) --> __x32_<sym> Originally, the syscalls in the x32 special range (512-547) were all compat. This assumption is now broken after the following commits: 55db9c0e8534 ("net: remove compat_sys_{get,set}sockopt") 5f764d624a89 ("fs: remove the compat readv/writev syscalls") 598b3cec831f ("fs: remove compat_sys_vmsplice") c3973b401ef2 ("mm: remove compat_process_vm_{readv,writev}") Those commits redefined __x32_sys_* to __x64_sys_* because there is no stub like __x32_sys_*. Defining them as follows is more sensible and cleaner. __SYSCALL_COMMON(nr, sym) --> __x64_<sym> __SYSCALL_X32(nr, sym) --> __x64_<sym> This works because both x86_64 and x32 use the same ABI (RDI, RSI, RDX, R10, R8, R9) The ugly #define __x32_sys_* will go away. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210517073815.97426-2-masahiroy@kernel.org
2020-10-03mm: remove compat_process_vm_{readv,writev}Christoph Hellwig1-0/+2
Now that import_iovec handles compat iovecs, the native syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03fs: remove compat_sys_vmspliceChristoph Hellwig1-0/+1
Now that import_iovec handles compat iovecs, the native vmsplice syscall can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-10-03fs: remove the compat readv/writev syscallsChristoph Hellwig1-0/+2
Now that import_iovec handles compat iovecs, the native readv and writev syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-20net: remove compat_sys_{get,set}sockoptChristoph Hellwig1-0/+7
Now that the ->compat_{get,set}sockopt proto_ops methods are gone there is no good reason left to keep the compat syscalls separate. This fixes the odd use of unsigned int for the compat_setsockopt optlen and the missing sock_use_custom_sol_socket. It would also easily allow running the eBPF hooks for the compat syscalls, but such a large change in behavior does not belong into a consolidation patch like this one. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-21x86/entry: Drop asmlinkage from syscallsBrian Gerst1-2/+2
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
2020-03-21x86/entry: Remove ABI prefixes from functions in syscall tablesBrian Gerst1-4/+4
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 <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-13-brgerst@gmail.com
2020-03-21x86/entry/64: Add __SYSCALL_COMMON()Brian Gerst1-0/+3
Add a __SYSCALL_COMMON() macro to the syscall table, which simplifies syscalltbl.sh. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-12-brgerst@gmail.com
2020-03-21x86/entry: Remove syscall qualifier supportBrian Gerst1-3/+3
Syscall qualifier support is no longer needed. 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/20200313195144.164260-11-brgerst@gmail.com
2020-03-21x86/entry: Move max syscall number calculation to syscallhdr.shBrian Gerst1-3/+3
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 <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-9-brgerst@gmail.com
2020-03-21x86/entry/64: Split X32 syscall table into its own fileBrian Gerst1-0/+26
Since X32 has its own syscall table now, move it to a separate file. 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/20200313195144.164260-8-brgerst@gmail.com
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