X-Git-Url: http://git.lttng.org/?p=ust.git;a=blobdiff_plain;f=include%2Fust%2Fprocessor.h;h=db39ee8b5382ac249ab77b5ad467f537034a7dcc;hp=bc24e7edddc39cd3f938e4388ccd4b416550cc72;hb=a09dac63957396890b1085cac0fee92ecc5db87a;hpb=636ca5d6fed61d16178a2e29038a6ffea26677fa diff --git a/include/ust/processor.h b/include/ust/processor.h index bc24e7e..db39ee8 100644 --- a/include/ust/processor.h +++ b/include/ust/processor.h @@ -1,3 +1,20 @@ +/* Copyright (C) 2009 Pierre-Marc Fournier + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + #ifndef UST_PROCESSOR_H #define UST_PROCESSOR_H @@ -7,43 +24,190 @@ extern __thread long ust_reg_stack[500]; extern volatile __thread long *ust_reg_stack_ptr; - -#ifdef X86_32 +#ifndef __x86_64 struct registers { - long eax; - long ebx; - long ecx; - long edx; - long ebp; - long esp; + short ss; + short cs; long esi; + long ebp; + long edx; long edi; - int xds; - int xes; - int xfs; - int xgs; - long eip; - int xcs; + long ecx; + long ebx; + long eax; long eflags; - int xss; + long esp; }; -static inline save_registers(struct registers *regs) -{ -} +#ifdef CONFIG_UST_GDB_INTEGRATION + +/* save_registers - saves most of the processor's registers so + * they are available to the probe. gdb uses this to give the + * value of local variables. + * + * Saving all registers without losing any of their values is + * tricky. + * + * We cannot pass to the asm stub the address of a registers structure + * on the stack, because it will use a register and override its value. + * + * We don't want to use a stub to push the regs on the stack and then + * another stub to copy them to a structure because changing %sp in asm + * and then returning to C (even briefly) can have unexpected results. + * Also, gcc might modify %sp between the stubs in reaction to the + * register needs of the second stub that needs to know where to copy + * the register values. + * + * So the chosen approach is to use another stack, declared in thread- + * local storage, to push the registers. They are subsequently copied + * to the stack, by C code. + */ + +#define save_registers(regsptr) \ + asm volatile ( \ + /* save original esp */ \ + "pushl %%esp\n\t" \ + /* push original eflags */ \ + "pushfl\n\t" \ + /* eax will hold the ptr to the private stack bottom */ \ + "pushl %%eax\n\t" \ + /* ebx is used for TLS access */ \ + "pushl %%ebx\n\t" \ + /* ecx will be used to temporarily hold the stack bottom addr */\ + "pushl %%ecx\n\t" \ + /* rdi is the input to __tls_get_addr, and also a temp var */ \ + "pushl %%edi\n\t" \ + /* For TLS access, we have to do function calls. However, \ + * we must not lose the original value of: \ + * esp, eflags, eax, ebx, ecx, edx, esi, edi, ebp, cs, ss \ + * \ + * Some registers' original values have already been saved: \ + * esp, eflags, eax, ebx, ecx, edi \ + * \ + * In addition, the i386 ABI says the following registers belong\ + * to the caller function: \ + * esp, ebp, esi, edi, ebx \ + * \ + * The following registers should not be changed by the callee: \ + * cs, ss \ + * \ + * Therefore, the following registers must be explicitly \ + * preserved: \ + * edx \ + */ \ + "pushl %%edx\n\t" \ + /* Get GOT address */ \ + "call __i686.get_pc_thunk.bx\n\t" \ + "addl $_GLOBAL_OFFSET_TABLE_, %%ebx\n\t" \ + /* Start TLS access of private reg stack pointer */ \ + "leal ust_reg_stack_ptr@tlsgd(,%%ebx,1),%%eax\n\t" \ + "call ___tls_get_addr@plt\n\t" \ + /* --- End TLS access */ \ + /* check if ust_reg_stack_ptr has been initialized */ \ + "movl (%%eax),%%ecx\n\t" \ + "testl %%ecx,%%ecx\n\t" \ + "jne 1f\n\t" \ + "movl %%eax,%%ecx\n\t" \ + /* Save ecx because we are using it. */ \ + "pushl %%ecx\n\t" \ + /* Start TLS access of private reg stack */ \ + "leal ust_reg_stack@tlsgd(,%%ebx,1),%%eax\n\t" \ + "call ___tls_get_addr@plt\n\t" \ + /* --- End TLS access */ \ + "popl %%ecx\n\t" \ + "addl $500,%%eax\n\t" \ + "movl %%eax,(%%ecx)\n\t" \ + "movl %%ecx,%%eax\n\t" \ + /* now the pointer to the private stack is in eax. \ + must add stack size so the ptr points to the stack bottom. */ \ + "1:\n\t" \ + /* edx was pushed for function calls */ \ + "popl %%edx\n\t" \ + /* Manually push esp to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 20(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* Manually push eflags to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 16(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* Manually push eax to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 12(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* Manually push ebx to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 8(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* Manually push ecx to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 4(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* Manually push edi to private stack */ \ + "addl $-4,(%%eax)\n\t" \ + "movl 0(%%esp), %%edi\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edi, (%%ebx)\n\t" \ + /* now push regs to tls */ \ + /* -- esp already pushed -- */ \ + /* -- eax already pushed -- */ \ + /* -- ebx already pushed -- */ \ + /* -- ecx already pushed -- */ \ + /* -- edi already pushed -- */ \ + "addl $-4,(%%eax)\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%edx,(%%ebx)\n\t" \ + "addl $-4,(%%eax)\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%ebp,(%%ebx)\n\t" \ + "addl $-4,(%%eax)\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movl %%esi,(%%ebx)\n\t" \ + /* push cs */ \ + "addl $-2,(%%eax)\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movw %%cs, (%%ebx)\n\t" \ + /* push ss */ \ + "addl $-2,(%%eax)\n\t" \ + "movl (%%eax), %%ebx\n\t" \ + "movw %%ss, (%%ebx)\n\t" \ + /* restore original values of regs that were used internally */ \ + "popl %%edi\n\t" \ + "popl %%ecx\n\t" \ + "popl %%ebx\n\t" \ + "popl %%eax\n\t" \ + /* cancel push of rsp */ \ + "addl $4,%%esp\n\t" \ + /* cancel push of eflags */ \ + "addl $4,%%esp\n\t" \ + ::: "memory"); \ + memcpy(regsptr, (void *)ust_reg_stack_ptr, sizeof(struct registers)); \ + ust_reg_stack_ptr = (void *)(((long)ust_reg_stack_ptr) + sizeof(struct registers)); + +#else /* CONFIG_UST_GDB_INTEGRATION */ + +#define save_registers(a) + +#endif /* CONFIG_UST_GDB_INTEGRATION */ #define RELATIVE_ADDRESS(__rel_label__) __rel_label__ +#define ARCH_COPY_ADDR(src, dst) "lea " src "," dst + #define _ASM_PTR ".long " -#else +#else /* below is code for x86-64 */ struct registers { int padding; /* 4 bytes */ short ss; short cs; - unsigned long rflags; unsigned long r15; unsigned long r14; unsigned long r13; @@ -59,31 +223,90 @@ struct registers { unsigned long rdi; unsigned long rbx; unsigned long rax; + unsigned long rflags; unsigned long rsp; }; +#ifdef CONFIG_UST_GDB_INTEGRATION + #define save_registers(regsptr) \ - if(ust_reg_stack_ptr == NULL) { \ - ust_reg_stack_ptr = (long*)((long)ust_reg_stack)+500; \ - } \ asm volatile ( \ /* save original rsp */ \ "pushq %%rsp\n\t" \ + /* push original rflags */ \ + "pushfq\n\t" \ /* rax will hold the ptr to the private stack bottom */ \ "pushq %%rax\n\t" \ /* rbx will be used to temporarily hold the stack bottom addr */ \ "pushq %%rbx\n\t" \ /* rdi is the input to __tls_get_addr, and also a temp var */ \ "pushq %%rdi\n\t" \ - /* Start TLS access of private reg stack */ \ + /* For TLS access, we have to do function calls. However, \ + * we must not lose the original value of: \ + * rsp, rflags, rax, rbx, rcx, rdx, rsi, rdi, rbp, r8, r9 \ + * r10, r11, r12, r13, r14, r15, cs, ss \ + * \ + * Some registers' original values have already been saved: \ + * rsp, rflags, rax, rbx, rdi \ + * \ + * In addition, the x86-64 ABI says the following registers \ + * belong to the caller function: \ + * rbp, rbx, r12, r13, r14, r15 \ + * \ + * The following registers should not be changed by the callee: \ + * cs, ss \ + * \ + * Therefore, the following registers must be explicitly \ + * preserved: \ + * rcx, rdx, rsi, r8, r9, r10, r11 \ + */ \ + "pushq %%rcx\n\t" \ + "pushq %%rdx\n\t" \ + "pushq %%rsi\n\t" \ + "pushq %%r8\n\t" \ + "pushq %%r9\n\t" \ + "pushq %%r10\n\t" \ + "pushq %%r11\n\t" \ + /* Start TLS access of private reg stack pointer */ \ ".byte 0x66\n\t" \ "leaq ust_reg_stack_ptr@tlsgd(%%rip), %%rdi\n\t" \ ".word 0x6666\n\t" \ "rex64\n\t" \ "call __tls_get_addr@plt\n\t" \ /* --- End TLS access */ \ + /* check if ust_reg_stack_ptr has been initialized */ \ + "movq (%%rax),%%rbx\n\t" \ + "testq %%rbx,%%rbx\n\t" \ + "jne 1f\n\t" \ + "movq %%rax,%%rbx\n\t" \ + /* Start TLS access of private reg stack */ \ + ".byte 0x66\n\t" \ + "leaq ust_reg_stack@tlsgd(%%rip), %%rdi\n\t" \ + ".word 0x6666\n\t" \ + "rex64\n\t" \ + "call __tls_get_addr@plt\n\t" \ + /* --- End TLS access */ \ + "addq $500,%%rax\n\t" \ + "movq %%rax,(%%rbx)\n\t" \ + "movq %%rbx,%%rax\n\t" \ + /* now the pointer to the private stack is in rax. + must add stack size so the ptr points to the stack bottom. */ \ + "1:\n\t" \ + /* Pop regs that were pushed for function calls */ \ + "popq %%r11\n\t" \ + "popq %%r10\n\t" \ + "popq %%r9\n\t" \ + "popq %%r8\n\t" \ + "popq %%rsi\n\t" \ + "popq %%rdx\n\t" \ + "popq %%rcx\n\t" \ /* Manually push rsp to private stack */ \ "addq $-8,(%%rax)\n\t" \ + "movq 32(%%rsp), %%rdi\n\t" \ + "movq (%%rax), %%rbx\n\t" \ + "movq %%rdi, (%%rbx)\n\t" \ + /* Manually push eflags to private stack */ \ + "addq $-8,(%%rax)\n\t" \ "movq 24(%%rsp), %%rdi\n\t" \ "movq (%%rax), %%rbx\n\t" \ "movq %%rdi, (%%rbx)\n\t" \ @@ -143,11 +366,6 @@ struct registers { "addq $-8,(%%rax)\n\t" \ "movq (%%rax), %%rbx\n\t" \ "movq %%r15,(%%rbx)\n\t" \ - /* deal with rflags */ \ - "pushfq\n\t" /* push rflags on stack */ \ - "addq $-8,(%%rax)\n\t" \ - "movq (%%rax), %%rbx\n\t" \ - "popq (%%rbx)\n\t" \ /* push cs */ \ "addq $-2,(%%rax)\n\t" \ "movq (%%rax), %%rbx\n\t" \ @@ -164,14 +382,24 @@ struct registers { "popq %%rax\n\t" \ /* cancel push of rsp */ \ "addq $8,%%rsp\n\t" \ + /* cancel push of rflags */ \ + "addq $8,%%rsp\n\t" \ ::); \ memcpy(regsptr, (void *)ust_reg_stack_ptr, sizeof(struct registers)); \ ust_reg_stack_ptr = (void *)(((long)ust_reg_stack_ptr) + sizeof(struct registers)); +#else /* CONFIG_UST_GDB_INTEGRATION */ + +#define save_registers(a) + +#endif /* CONFIG_UST_GDB_INTEGRATION */ + /* Macro to insert the address of a relative jump in an assembly stub, * in a relocatable way. On x86-64, this uses a special (%rip) notation. */ #define RELATIVE_ADDRESS(__rel_label__) __rel_label__(%%rip) +#define ARCH_COPY_ADDR(src, dst) "lea " src "(%%rip)," dst + #define _ASM_PTR ".quad " #endif