Commit 73cbf687 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Ingo Molnar

x86/asm/entry/32: Open-code LOAD_ARGS32

This macro is small, has only three callsites, and one of them
is slightly different using a conditional parameter.

A few saved lines aren't worth the resulting obfuscation.

Generated machine code is identical.
Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1433271842-9139-2-git-send-email-dvlasenk@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ef0cd5dc
...@@ -29,28 +29,6 @@ ...@@ -29,28 +29,6 @@
.section .entry.text, "ax" .section .entry.text, "ax"
/*
* Reload arg registers from stack in case ptrace changed them.
* We don't reload %eax because syscall_trace_enter() returned
* the %rax value we should see. Instead, we just truncate that
* value to 32 bits again as we did on entry from user mode.
* If it's a new value set by user_regset during entry tracing,
* this matches the normal truncation of the user-mode value.
* If it's -1 to make us punt the syscall, then (u32)-1 is still
* an appropriately invalid value.
*/
.macro LOAD_ARGS32 _r9=0
.if \_r9
movl R9(%rsp),%r9d
.endif
movl RCX(%rsp),%ecx
movl RDX(%rsp),%edx
movl RSI(%rsp),%esi
movl RDI(%rsp),%edi
movl %eax,%eax /* zero extension */
.endm
#ifdef CONFIG_PARAVIRT #ifdef CONFIG_PARAVIRT
ENTRY(native_usergs_sysret32) ENTRY(native_usergs_sysret32)
swapgs swapgs
...@@ -269,7 +247,14 @@ sysenter_tracesys: ...@@ -269,7 +247,14 @@ sysenter_tracesys:
movq %rax, R8(%rsp) movq %rax, R8(%rsp)
movq %rsp,%rdi /* &pt_regs -> arg1 */ movq %rsp,%rdi /* &pt_regs -> arg1 */
call syscall_trace_enter call syscall_trace_enter
LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
/* Reload arg registers from stack. (see sysenter_tracesys) */
movl RCX(%rsp), %ecx
movl RDX(%rsp), %edx
movl RSI(%rsp), %esi
movl RDI(%rsp), %edi
movl %eax, %eax /* zero extension */
RESTORE_EXTRA_REGS RESTORE_EXTRA_REGS
jmp sysenter_do_call jmp sysenter_do_call
ENDPROC(ia32_sysenter_target) ENDPROC(ia32_sysenter_target)
...@@ -413,7 +398,15 @@ cstar_tracesys: ...@@ -413,7 +398,15 @@ cstar_tracesys:
movq %rax, R8(%rsp) movq %rax, R8(%rsp)
movq %rsp,%rdi /* &pt_regs -> arg1 */ movq %rsp,%rdi /* &pt_regs -> arg1 */
call syscall_trace_enter call syscall_trace_enter
LOAD_ARGS32 1 /* reload args from stack in case ptrace changed it */ movl R9(%rsp),%r9d
/* Reload arg registers from stack. (see sysenter_tracesys) */
movl RCX(%rsp), %ecx
movl RDX(%rsp), %edx
movl RSI(%rsp), %esi
movl RDI(%rsp), %edi
movl %eax, %eax /* zero extension */
RESTORE_EXTRA_REGS RESTORE_EXTRA_REGS
xchgl %ebp,%r9d xchgl %ebp,%r9d
jmp cstar_do_call jmp cstar_do_call
...@@ -502,7 +495,18 @@ ia32_tracesys: ...@@ -502,7 +495,18 @@ ia32_tracesys:
SAVE_EXTRA_REGS SAVE_EXTRA_REGS
movq %rsp,%rdi /* &pt_regs -> arg1 */ movq %rsp,%rdi /* &pt_regs -> arg1 */
call syscall_trace_enter call syscall_trace_enter
LOAD_ARGS32 /* reload args from stack in case ptrace changed it */ /*
* Reload arg registers from stack in case ptrace changed them.
* Don't reload %eax because syscall_trace_enter() returned
* the %rax value we should see. But do truncate it to 32 bits.
* If it's -1 to make us punt the syscall, then (u32)-1 is still
* an appropriately invalid value.
*/
movl RCX(%rsp), %ecx
movl RDX(%rsp), %edx
movl RSI(%rsp), %esi
movl RDI(%rsp), %edi
movl %eax, %eax /* zero extension */
RESTORE_EXTRA_REGS RESTORE_EXTRA_REGS
jmp ia32_do_call jmp ia32_do_call
END(ia32_syscall) END(ia32_syscall)
......
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