Commit-ID: 1871853f7abc3c727c4346539c5062cbeaf016a4 Gitweb: http://git.kernel.org/tip/1871853f7abc3c727c4346539c5062cbeaf016a4 Author: Frederic Weisbecker <fweisbec@xxxxxxxxx> AuthorDate: Fri, 1 Jul 2011 01:51:22 +0200 Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx> CommitDate: Sat, 2 Jul 2011 18:05:31 +0200 x86,64: Simplify save_regs() The save_regs function that saves the regs on low level irq entry is complicated because of the fact it changes its stack in the middle and also because it manipulates data allocated in the caller frame and accesses there are directly calculated from callee rsp value with the return address in the middle of the way. This complicates the static stack offsets calculation and require more dynamic ones. It also needs a save/restore of the function's return address. To simplify and optimize this, turn save_regs() into a macro. Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Jan Beulich <JBeulich@xxxxxxxxxx> --- arch/x86/kernel/entry_64.S | 44 +++++++++++++++++--------------------------- 1 files changed, 17 insertions(+), 27 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 8a445a0..b6b2e85 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -297,27 +297,22 @@ ENDPROC(native_usergs_sysret64) .endm /* save partial stack frame */ - .pushsection .kprobes.text, "ax" -ENTRY(save_args) - XCPT_FRAME + .macro SAVE_ARGS_IRQ cld - /* - * start from rbp in pt_regs and jump over - * return address. - */ - movq_cfi rdi, RDI+8-RBP - movq_cfi rsi, RSI+8-RBP - movq_cfi rdx, RDX+8-RBP - movq_cfi rcx, RCX+8-RBP - movq_cfi rax, RAX+8-RBP - movq_cfi r8, R8+8-RBP - movq_cfi r9, R9+8-RBP - movq_cfi r10, R10+8-RBP - movq_cfi r11, R11+8-RBP - - leaq -RBP+8(%rsp),%rdi /* arg1 for handler */ - movq_cfi rbp, 8 /* push %rbp */ - leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ + /* start from rbp in pt_regs and jump over */ + movq_cfi rdi, RDI-RBP + movq_cfi rsi, RSI-RBP + movq_cfi rdx, RDX-RBP + movq_cfi rcx, RCX-RBP + movq_cfi rax, RAX-RBP + movq_cfi r8, R8-RBP + movq_cfi r9, R9-RBP + movq_cfi r10, R10-RBP + movq_cfi r11, R11-RBP + + leaq -RBP(%rsp),%rdi /* arg1 for handler */ + movq_cfi rbp, 0 /* push %rbp */ + movq %rsp, %rbp testl $3, CS(%rdi) je 1f SWAPGS @@ -329,19 +324,14 @@ ENTRY(save_args) */ 1: incl PER_CPU_VAR(irq_count) jne 2f - popq_cfi %rax /* move return address... */ mov PER_CPU_VAR(irq_stack_ptr),%rsp EMPTY_FRAME 0 pushq_cfi %rbp /* backlink for unwinder */ - pushq_cfi %rax /* ... to the new stack */ /* * We entered an interrupt context - irqs are off: */ 2: TRACE_IRQS_OFF - ret - CFI_ENDPROC -END(save_args) - .popsection + .endm ENTRY(save_rest) PARTIAL_FRAME 1 REST_SKIP+8 @@ -791,7 +781,7 @@ END(interrupt) /* reserve pt_regs for scratch regs and rbp */ subq $ORIG_RAX-RBP, %rsp CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP - call save_args + SAVE_ARGS_IRQ PARTIAL_FRAME 0 call \func .endm -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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