kernel/linux.git/arch/x86/include/asm/syscall_wrapper.h, branch v6.19.11

x86/entry/ia32: Ensure s32 is sign extended to s64

2024-01-24T10:49:19+00:00

Presently ia32 registers stored in ptregs are unconditionally cast to unsigned int by the ia32 stub. They are then cast to long when passed to __se_sys*, but will not be sign extended. This takes the sign of the syscall argument into account in the ia32 stub. It still casts to unsigned int to avoid implementation specific behavior. However then casts to int or unsigned int as necessary. So that the following cast to long sign extends the value. This fixes the io_pgetevents02 LTP test when compiled with -m32. Presently the systemcall io_pgetevents_time64() unexpectedly accepts -1 for the maximum number of events. It doesn't appear other systemcalls with signed arguments are effected because they all have compat variants defined and wired up. Fixes: ebeb8c82ffaf ("syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32") Suggested-by: Arnd Bergmann Signed-off-by: Richard Palethorpe Signed-off-by: Nikolay Borisov Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240110130122.3836513-1-nik.borisov@suse.com Link: https://lore.kernel.org/ltp/20210921130127.24131-1-rpalethorpe@suse.com/

posix-timers: Get rid of [COMPAT_]SYS_NI() uses

2023-12-21T05:30:27+00:00

Only the posix timer system calls use this (when the posix timer support is disabled, which does not actually happen in any normal case), because they had debug code to print out a warning about missing system calls. Get rid of that special case, and just use the standard COND_SYSCALL interface that creates weak system call stubs that return -ENOSYS for when the system call does not exist. This fixes a kCFI issue with the SYS_NI() hackery: CFI failure at int80_emulation+0x67/0xb0 (target: sys_ni_posix_timers+0x0/0x70; expected type: 0xb02b34d9) WARNING: CPU: 0 PID: 48 at int80_emulation+0x67/0xb0 Reported-by: kernel test robot Reviewed-by: Sami Tolvanen Tested-by: Sami Tolvanen Cc: Thomas Gleixner Cc: Dave Hansen Cc: Borislav Petkov Signed-off-by: Linus Torvalds

x86/syscall: Include asm/ptrace.h in syscall_wrapper header

2022-10-24T15:57:28+00:00

With just the forward declaration of the 'struct pt_regs' in syscall_wrapper.h, the syscall stub functions: __[x64|ia32]_sys_*(struct pt_regs *regs) will have different definition of 'regs' argument in BTF data based on which object file they are defined in. If the syscall's object includes 'struct pt_regs' definition, the BTF argument data will point to a 'struct pt_regs' record, like: [226] STRUCT 'pt_regs' size=168 vlen=21 'r15' type_id=1 bits_offset=0 'r14' type_id=1 bits_offset=64 'r13' type_id=1 bits_offset=128 ... If not, it will point to a fwd declaration record: [15439] FWD 'pt_regs' fwd_kind=struct and make bpf tracing program hooking on those functions unable to access fields from 'struct pt_regs'. Include asm/ptrace.h directly in syscall_wrapper.h to make sure all syscalls see 'struct pt_regs' definition. This then results in BTF for '__*_sys_*(struct pt_regs *regs)' functions to point to the actual struct, not just the forward declaration. [ bp: No Fixes tag as this is not really a bug fix but "adjustment" so that BTF is happy. ] Reported-by: Akihiro HARAI Signed-off-by: Jiri Olsa Signed-off-by: Borislav Petkov Acked-by: Andrii Nakryiko Cc: # this is needed only for BTF so kernels >= 5.15 Link: https://lore.kernel.org/r/20221018122708.823792-1-jolsa@kernel.org

x86: Remove toolchain check for X32 ABI capability

2022-03-15T09:32:48+00:00

Commit 0bf6276392e9 ("x32: Warn and disable rather than error if binutils too old") added a small test in arch/x86/Makefile because binutils 2.22 or newer is needed to properly support elf32-x86-64. This check is no longer necessary, as the minimum supported version of binutils is 2.23, which is enforced at configuration time with scripts/min-tool-version.sh. Remove this check and replace all uses of CONFIG_X86_X32 with CONFIG_X86_X32_ABI, as two symbols are no longer necessary. [nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still used, and simplify commit message to satisfy -tip requirements] Signed-off-by: Masahiro Yamada Signed-off-by: Nathan Chancellor Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org

x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_*

2021-05-20T13:03:58+00:00

The SYSCALL macros are mapped to symbols as follows: __SYSCALL_COMMON(nr, sym) --> __x64_ __SYSCALL_X32(nr, sym) --> __x32_ 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_ __SYSCALL_X32(nr, sym) --> __x64_ 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 Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210517073815.97426-2-masahiroy@kernel.org

x86/syscalls: Fix -Wmissing-prototypes warnings from COND_SYSCALL()

2021-03-25T15:20:41+00:00

Building kernel/sys_ni.c with W=1 emits tons of -Wmissing-prototypes warnings: $ make W=1 kernel/sys_ni.o [ snip ] CC kernel/sys_ni.o ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes] ... The problem is in __COND_SYSCALL(), the __SYS_STUB0() and __SYS_STUBx() macros defined a few lines above already have forward declarations. Let's do likewise for __COND_SYSCALL() to fix the warnings. Signed-off-by: Masahiro Yamada Signed-off-by: Ingo Molnar Tested-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210301131533.64671-2-masahiroy@kernel.org

x86/entry: Fix build error x86 with !CONFIG_POSIX_TIMERS

2020-03-25T09:06:20+00:00

Add missing semicolon. Fixes: a74d187c2df3 ("x86/entry: Refactor SYS_NI macros") Reported-by: Ingo Molnar Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200324143520.898733-1-brgerst@gmail.com

x86/entry: Drop asmlinkage from syscalls

2020-03-21T15:03:25+00:00

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

2020-03-21T15:03:24+00:00

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/64: Move sys_ni_syscall stub to common.c

2020-03-21T15:03:20+00:00

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 Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200313195144.164260-7-brgerst@gmail.com