Merge tag 'x86_entry_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 entry code updates from Dave Hansen:
"This is entirely composed of a set of long overdue VDSO cle

Merge tag 'x86_entry_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 entry code updates from Dave Hansen:
"This is entirely composed of a set of long overdue VDSO cleanups. They
makes the VDSO build much more logical and zap quite a bit of old
cruft.

It also results in a coveted net-code-removal diffstat"

* tag 'x86_entry_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry/vdso: Add vdso2c to .gitignore
x86/entry/vdso32: Omit '.cfi_offset eflags' for LLVM < 16
MAINTAINERS: Adjust vdso file entry in INTEL SGX
x86/entry/vdso/selftest: Update location of vgetrandom-chacha.S
x86/entry/vdso: Fix filtering of vdso compiler flags
x86/entry/vdso: Update the object paths for "make vdso_install"
x86/entry/vdso32: When using int $0x80, use it directly
x86/cpufeature: Replace X86_FEATURE_SYSENTER32 with X86_FEATURE_SYSFAST32
x86/vdso: Abstract out vdso system call internals
x86/entry/vdso: Include GNU_PROPERTY and GNU_STACK PHDRs
x86/entry/vdso32: Remove open-coded DWARF in sigreturn.S
x86/entry/vdso32: Remove SYSCALL_ENTER_KERNEL macro in sigreturn.S
x86/entry/vdso32: Don't rely on int80_landing_pad for adjusting ip
x86/entry/vdso: Refactor the vdso build
x86/entry/vdso: Move vdso2c to arch/x86/tools
x86/entry/vdso: Rename vdso_image_* to vdso*_image

show more ...

x86/entry/vdso32: When using int $0x80, use it directly

When neither sysenter32 nor syscall32 is available (on either
FRED-capable 64-bit hardware or old 32-bit hardware), there is no
reason to do a

x86/entry/vdso32: When using int $0x80, use it directly

When neither sysenter32 nor syscall32 is available (on either
FRED-capable 64-bit hardware or old 32-bit hardware), there is no
reason to do a bunch of stack shuffling in __kernel_vsyscall.
Unfortunately, just overwriting the initial "push" instructions will
mess up the CFI annotations, so suffer the 3-byte NOP if not
applicable.

Similarly, inline the int $0x80 when doing inline system calls in the
vdso instead of calling __kernel_vsyscall.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-11-hpa@zytor.com

show more ...

x86/vdso: Abstract out vdso system call internals

Abstract out the calling of true system calls from the vdso into
macros.

It has been a very long time since gcc did not allow %ebx or %ebp in
inlin

x86/vdso: Abstract out vdso system call internals

Abstract out the calling of true system calls from the vdso into
macros.

It has been a very long time since gcc did not allow %ebx or %ebp in
inline asm in 32-bit PIC mode; remove the corresponding hacks.

Remove the use of memory output constraints in gettimeofday.h in favor
of "memory" clobbers. The resulting code is identical for the current
use cases, as the system call is usually a terminal fallback anyway,
and it merely complicates the macroization.

This patch adds only a handful of more lines of code than it removes,
and in fact could be made substantially smaller by removing the macros
for the argument counts that aren't currently used, however, it seems
better to be general from the start.

[ v3: remove stray comment from prototyping; remove VDSO_SYSCALL6()
since it would require special handling on 32 bits and is
currently unused. (Uros Biszjak)

Indent nested preprocessor directives. ]

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://patch.msgid.link/20251216212606.1325678-9-hpa@zytor.com

show more ...