kernel/linux.git/arch/x86/entry/Makefile, branch v6.19.11

x86/syscall: Move sys_ni_syscall()

2025-03-19T10:19:17+00:00

Move sys_ni_syscall() to kernel/process.c, and remove the now empty entry/common.c No functional changes. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Josh Poimboeuf Link: https://lore.kernel.org/r/20250314151220.862768-6-brgerst@gmail.com

x86/syscall/x32: Move x32 syscall table

2025-03-19T10:19:15+00:00

Since commit: 2e958a8a510d ("x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_*") the ABI prefix for x32 syscalls is the same as native 64-bit syscalls. Move the x32 syscall table to syscall_64.c No functional changes. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Josh Poimboeuf Link: https://lore.kernel.org/r/20250314151220.862768-5-brgerst@gmail.com

x86/syscall/64: Move 64-bit syscall dispatch code

2025-03-19T10:19:04+00:00

Move the 64-bit syscall dispatch code to syscall_64.c. No functional changes. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Josh Poimboeuf Link: https://lore.kernel.org/r/20250314151220.862768-4-brgerst@gmail.com

x86/syscall/32: Move 32-bit syscall dispatch code

2025-03-19T10:19:01+00:00

Move the 32-bit syscall dispatch code to syscall_32.c. No functional changes. Signed-off-by: Brian Gerst Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Josh Poimboeuf Link: https://lore.kernel.org/r/20250314151220.862768-3-brgerst@gmail.com

x86/entry: Merge thunk_64.S and thunk_32.S into thunk.S

2024-04-09T07:57:56+00:00

The code in thunk_64.S and thunk_32.S are exactly the same except for the comments. Merge them in to thunk.S. And since thunk_32.S was originated from thunk_64.S, the new merged thunk.S is actually renamed from thunk_64.S. Signed-off-by: Lai Jiangshan Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240407090558.3395-9-jiangshanlai@gmail.com

x86/fred: FRED entry/exit and dispatch code

2024-01-31T21:02:31+00:00

The code to actually handle kernel and event entry/exit using FRED. It is split up into two files thus: - entry_64_fred.S contains the actual entrypoints and exit code, and saves and restores registers. - entry_fred.c contains the two-level event dispatch code for FRED. The first-level dispatch is on the event type, and the second-level is on the event vector. [ bp: Fold in an allmodconfig clang build fix: https://lore.kernel.org/r/20240129064521.5168-1-xin3.li@intel.com and a CONFIG_IA32_EMULATION=n build fix: https://lore.kernel.org/r/20240127093728.1323-3-xin3.li@intel.com] Suggested-by: Thomas Gleixner Originally-by: Megha Dey Co-developed-by: Xin Li Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Tested-by: Shan Kang Link: https://lore.kernel.org/r/20231209214214.2932-1-xin3.li@intel.com

x86/entry: Build thunk_$(BITS) only if CONFIG_PREEMPTION=y

2022-08-04T10:23:50+00:00

With CONFIG_PREEMPTION disabled, arch/x86/entry/thunk_$(BITS).o becomes an empty object file. With some old versions of binutils (i.e., 2.35.90.20210113-1ubuntu1) the GNU assembler doesn't generate a symbol table for empty object files and objtool fails with the following error when a valid symbol table cannot be found: arch/x86/entry/thunk_64.o: warning: objtool: missing symbol table To prevent this from happening, build thunk_$(BITS).o only if CONFIG_PREEMPTION is enabled. BugLink: https://bugs.launchpad.net/bugs/1911359 Fixes: 320100a5ffe5 ("x86/entry: Remove the TRACE_IRQS cruft") Signed-off-by: Andrea Righi Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/Ys/Ke7EWjcX+ZlXO@arighi-desktop

x86/bugs: Add retbleed=ibpb

2022-06-27T08:34:00+00:00

jmp2ret mitigates the easy-to-attack case at relatively low overhead. It mitigates the long speculation windows after a mispredicted RET, but it does not mitigate the short speculation window from arbitrary instruction boundaries. On Zen2, there is a chicken bit which needs setting, which mitigates "arbitrary instruction boundaries" down to just "basic block boundaries". But there is no fix for the short speculation window on basic block boundaries, other than to flush the entire BTB to evict all attacker predictions. On the spectrum of "fast & blurry" -> "safe", there is (on top of STIBP or no-SMT): 1) Nothing System wide open 2) jmp2ret May stop a script kiddy 3) jmp2ret+chickenbit Raises the bar rather further 4) IBPB Only thing which can count as "safe". Tentative numbers put IBPB-on-entry at a 2.5x hit on Zen2, and a 10x hit on Zen1 according to lmbench. [ bp: Fixup feature bit comments, document option, 32-bit build fix. ] Suggested-by: Andrew Cooper Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov

x86/syscalls: Don't adjust CFLAGS for syscall tables

2021-05-25T14:59:23+00:00

The syscall_*.c files only contain data (the syscall tables). There is no need to adjust CFLAGS for tracing and stack protector since they contain no code. Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Reviewed-by: Masahiro Yamada Link: https://lore.kernel.org/r/20210524181707.132844-4-brgerst@gmail.com

x86/syscalls: Remove -Wno-override-init for syscall tables

2021-05-25T14:59:23+00:00

Commit 44fe4895f47c ("Stop filling syscall arrays with *_sys_ni_syscall") removes the need for -Wno-override-init, since the table is now filled sequentially instead of overriding a default value. Signed-off-by: Brian Gerst Signed-off-by: Thomas Gleixner Reviewed-by: Masahiro Yamada Link: https://lore.kernel.org/r/20210524181707.132844-3-brgerst@gmail.com