+/* 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
extern __thread long ust_reg_stack[500];
extern volatile __thread long *ust_reg_stack_ptr;
-#ifndef __x86_64
+#ifdef __i386
struct registers {
short ss;
long esp;
};
+static inline int fls(int x)
+{
+ int r;
+ asm("bsrl %1,%0\n\t"
+ "cmovzl %2,%0"
+ : "=&r" (r) : "rm" (x), "rm" (-1));
+ return r + 1;
+}
+
#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 ( \
"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" \
+ /* 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" \
- /* Save registers before call (not using ecx yet but we must preserve \
- the original value of edx. */ \
- "pushl %%edx\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 */ \
- "popl %%edx\n\t" \
/* 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 registers before call (using ecx and we must preserve \
- the original value of edx. */ \
+ /* Save ecx because we are using it. */ \
"pushl %%ecx\n\t" \
- "pushl %%edx\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 %%edx\n\t" \
"popl %%ecx\n\t" \
"addl $500,%%eax\n\t" \
"movl %%eax,(%%ecx)\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" \
#define RELATIVE_ADDRESS(__rel_label__) __rel_label__
+#define ARCH_COPY_ADDR(dst) "lea 2b," dst "\n\t"
+
#define _ASM_PTR ".long "
-#else /* below is code for x86-64 */
+#endif /* below is code for x86-64 */
+
+#ifdef __x86_64
struct registers {
int padding; /* 4 bytes */
unsigned long rsp;
};
+static inline int fls(int x)
+{
+ int r;
+ asm("bsrl %1,%0\n\t"
+ "cmovzl %2,%0"
+ : "=&r" (r) : "rm" (x), "rm" (-1));
+ return r + 1;
+}
+
#ifdef CONFIG_UST_GDB_INTEGRATION
#define save_registers(regsptr) \
"pushq %%rbx\n\t" \
/* rdi is the input to __tls_get_addr, and also a temp var */ \
"pushq %%rdi\n\t" \
+ /* 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" \
/* 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" \
* 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(dst) "lea 2b(%%rip)," dst "\n\t"
+
#define _ASM_PTR ".quad "
-#endif
+#endif /* x86_64 */
+
+#ifdef __PPC__
+
+struct registers {
+};
+
+static __inline__ int fls(unsigned int x)
+{
+ int lz;
+
+ asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
+ return 32 - lz;
+}
+
+#define ARCH_COPY_ADDR(dst) \
+ "lis " dst ",2b@h\n\t" /* load high bytes */ \
+ "ori " dst "," dst ",2b@l\n\t" /* load low bytes */
+
+#define _ASM_PTR ".long "
+#define save_registers(a)
+
+#endif /* __PPC__ */
#endif /* UST_PROCESSOR_H */