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author | Alexander van Heukelum <heukelum@mailshack.com> | 2008-11-21 15:41:55 (GMT) |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-21 18:02:54 (GMT) |
commit | c002a1e6b6b6f07ae04e68987054bf1f2150ae48 (patch) | |
tree | b8d0e2dbbba95876f26243ce4a425481ed9d4094 /arch/x86/kernel/entry_64.S | |
parent | 14ae22ba2b8bb3d53fb795f9b8074aa39ef7b6cd (diff) | |
download | linux-fsl-qoriq-c002a1e6b6b6f07ae04e68987054bf1f2150ae48.tar.xz |
x86: introduce save_rest and restructure the PTREGSCALL macro in entry_64.S
Impact: cleanup
The save_rest function completes a partial stack frame for use
by the PTREGSCALL macro. This also avoids the indirect call in
PTREGSCALLs.
This adds the macro movq_cfi_restore to hide the CFI_RESTORE
annotation when restoring a register from the stack frame.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
-rw-r--r-- | arch/x86/kernel/entry_64.S | 91 |
1 files changed, 53 insertions, 38 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 92c5e18..ef95c45 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -78,6 +78,11 @@ CFI_REL_OFFSET \reg, \offset .endm + .macro movq_cfi_restore offset reg + movq \offset(%rsp), %\reg + CFI_RESTORE \reg + .endm + #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) @@ -186,21 +191,21 @@ ENTRY(native_usergs_sysret64) */ /* %rsp:at FRAMEEND */ - .macro FIXUP_TOP_OF_STACK tmp - movq %gs:pda_oldrsp,\tmp - movq \tmp,RSP(%rsp) - movq $__USER_DS,SS(%rsp) - movq $__USER_CS,CS(%rsp) - movq $-1,RCX(%rsp) - movq R11(%rsp),\tmp /* get eflags */ - movq \tmp,EFLAGS(%rsp) + .macro FIXUP_TOP_OF_STACK tmp offset=0 + movq %gs:pda_oldrsp,\tmp + movq \tmp,RSP+\offset(%rsp) + movq $__USER_DS,SS+\offset(%rsp) + movq $__USER_CS,CS+\offset(%rsp) + movq $-1,RCX+\offset(%rsp) + movq R11+\offset(%rsp),\tmp /* get eflags */ + movq \tmp,EFLAGS+\offset(%rsp) .endm - .macro RESTORE_TOP_OF_STACK tmp,offset=0 - movq RSP-\offset(%rsp),\tmp - movq \tmp,%gs:pda_oldrsp - movq EFLAGS-\offset(%rsp),\tmp - movq \tmp,R11-\offset(%rsp) + .macro RESTORE_TOP_OF_STACK tmp offset=0 + movq RSP+\offset(%rsp),\tmp + movq \tmp,%gs:pda_oldrsp + movq EFLAGS+\offset(%rsp),\tmp + movq \tmp,R11+\offset(%rsp) .endm .macro FAKE_STACK_FRAME child_rip @@ -333,6 +338,21 @@ ENTRY(save_args) CFI_ENDPROC END(save_args) +ENTRY(save_rest) + PARTIAL_FRAME 1 REST_SKIP+8 + movq 5*8+16(%rsp), %r11 /* save return address */ + movq_cfi rbx, RBX+16 + movq_cfi rbp, RBP+16 + movq_cfi r12, R12+16 + movq_cfi r13, R13+16 + movq_cfi r14, R14+16 + movq_cfi r15, R15+16 + movq %r11, 8(%rsp) /* return address */ + FIXUP_TOP_OF_STACK %r11, 16 + ret + CFI_ENDPROC +END(save_rest) + /* * A newly forked process directly context switches into this. */ @@ -353,7 +373,7 @@ rff_action: je int_ret_from_sys_call testl $_TIF_IA32,TI_flags(%rcx) jnz int_ret_from_sys_call - RESTORE_TOP_OF_STACK %rdi,ARGOFFSET + RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET jmp ret_from_sys_call rff_trace: movq %rsp,%rdi @@ -626,18 +646,20 @@ END(system_call) /* * Certain special system calls that need to save a complete full stack frame. */ - .macro PTREGSCALL label,func,arg - .globl \label -\label: - leaq \func(%rip),%rax - leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ - jmp ptregscall_common +ENTRY(\label) + PARTIAL_FRAME 1 8 /* offset 8: return address */ + subq $REST_SKIP, %rsp + CFI_ADJUST_CFA_OFFSET REST_SKIP + call save_rest + DEFAULT_FRAME 0 8 /* offset 8: return address */ + leaq 8(%rsp), \arg /* pt_regs pointer */ + call \func + jmp ptregscall_common + CFI_ENDPROC END(\label) .endm - CFI_STARTPROC - PTREGSCALL stub_clone, sys_clone, %r8 PTREGSCALL stub_fork, sys_fork, %rdi PTREGSCALL stub_vfork, sys_vfork, %rdi @@ -645,22 +667,15 @@ END(\label) PTREGSCALL stub_iopl, sys_iopl, %rsi ENTRY(ptregscall_common) - popq %r11 - CFI_ADJUST_CFA_OFFSET -8 - CFI_REGISTER rip, r11 - SAVE_REST - movq %r11, %r15 - CFI_REGISTER rip, r15 - FIXUP_TOP_OF_STACK %r11 - call *%rax - RESTORE_TOP_OF_STACK %r11 - movq %r15, %r11 - CFI_REGISTER rip, r11 - RESTORE_REST - pushq %r11 - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rip, 0 - ret + DEFAULT_FRAME 1 8 /* offset 8: return address */ + RESTORE_TOP_OF_STACK %r11, 8 + movq_cfi_restore R15+8, r15 + movq_cfi_restore R14+8, r14 + movq_cfi_restore R13+8, r13 + movq_cfi_restore R12+8, r12 + movq_cfi_restore RBP+8, rbp + movq_cfi_restore RBX+8, rbx + ret $REST_SKIP /* pop extended registers */ CFI_ENDPROC END(ptregscall_common) |