aboutsummaryrefslogtreecommitdiff
path: root/src/common/linux/breakpad_getcontext.S
diff options
context:
space:
mode:
Diffstat (limited to 'src/common/linux/breakpad_getcontext.S')
-rw-r--r--src/common/linux/breakpad_getcontext.S486
1 files changed, 486 insertions, 0 deletions
diff --git a/src/common/linux/breakpad_getcontext.S b/src/common/linux/breakpad_getcontext.S
new file mode 100644
index 00000000..fea0109d
--- /dev/null
+++ b/src/common/linux/breakpad_getcontext.S
@@ -0,0 +1,486 @@
+// Copyright (c) 2012, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A minimalistic implementation of getcontext() to be used by
+// Google Breakpad when getcontext() is not available in libc.
+
+#include "common/linux/ucontext_constants.h"
+
+/* int getcontext (ucontext_t *ucp) */
+
+#if defined(__arm__)
+
+ .text
+ .global breakpad_getcontext
+ .hidden breakpad_getcontext
+ .type breakpad_getcontext, #function
+ .align 0
+ .fnstart
+breakpad_getcontext:
+
+ /* First, save r4-r11 */
+ add r1, r0, #(MCONTEXT_GREGS_OFFSET + 4*4)
+ stm r1, {r4-r11}
+
+ /* r12 is a scratch register, don't save it */
+
+ /* Save sp and lr explicitly. */
+ /* - sp can't be stored with stmia in Thumb-2 */
+ /* - STM instructions that store sp and pc are deprecated in ARM */
+ str sp, [r0, #(MCONTEXT_GREGS_OFFSET + 13*4)]
+ str lr, [r0, #(MCONTEXT_GREGS_OFFSET + 14*4)]
+
+ /* Save the caller's address in 'pc' */
+ str lr, [r0, #(MCONTEXT_GREGS_OFFSET + 15*4)]
+
+ /* Save ucontext_t* pointer across next call */
+ mov r4, r0
+
+ /* Call sigprocmask(SIG_BLOCK, NULL, &(ucontext->uc_sigmask)) */
+ mov r0, #0 /* SIG_BLOCK */
+ mov r1, #0 /* NULL */
+ add r2, r4, #UCONTEXT_SIGMASK_OFFSET
+ bl sigprocmask(PLT)
+
+ /* Intentionally do not save the FPU state here. This is because on
+ * Linux/ARM, one should instead use ptrace(PTRACE_GETFPREGS) or
+ * ptrace(PTRACE_GETVFPREGS) to get it.
+ *
+ * Note that a real implementation of getcontext() would need to save
+ * this here to allow setcontext()/swapcontext() to work correctly.
+ */
+
+ /* Restore the values of r4 and lr */
+ mov r0, r4
+ ldr lr, [r0, #(MCONTEXT_GREGS_OFFSET + 14*4)]
+ ldr r4, [r0, #(MCONTEXT_GREGS_OFFSET + 4*4)]
+
+ /* Return 0 */
+ mov r0, #0
+ bx lr
+
+ .fnend
+ .size breakpad_getcontext, . - breakpad_getcontext
+
+#elif defined(__aarch64__)
+
+#define _NSIG 64
+#define __NR_rt_sigprocmask 135
+
+ .text
+ .global breakpad_getcontext
+ .hidden breakpad_getcontext
+ .type breakpad_getcontext, #function
+ .align 4
+ .cfi_startproc
+breakpad_getcontext:
+
+ /* The saved context will return to the getcontext() call point
+ with a return value of 0 */
+ str xzr, [x0, MCONTEXT_GREGS_OFFSET + 0 * REGISTER_SIZE]
+
+ stp x18, x19, [x0, MCONTEXT_GREGS_OFFSET + 18 * REGISTER_SIZE]
+ stp x20, x21, [x0, MCONTEXT_GREGS_OFFSET + 20 * REGISTER_SIZE]
+ stp x22, x23, [x0, MCONTEXT_GREGS_OFFSET + 22 * REGISTER_SIZE]
+ stp x24, x25, [x0, MCONTEXT_GREGS_OFFSET + 24 * REGISTER_SIZE]
+ stp x26, x27, [x0, MCONTEXT_GREGS_OFFSET + 26 * REGISTER_SIZE]
+ stp x28, x29, [x0, MCONTEXT_GREGS_OFFSET + 28 * REGISTER_SIZE]
+ str x30, [x0, MCONTEXT_GREGS_OFFSET + 30 * REGISTER_SIZE]
+
+ /* Place LR into the saved PC, this will ensure that when
+ switching to this saved context with setcontext() control
+ will pass back to the caller of getcontext(), we have
+ already arranged to return the appropriate return value in x0
+ above. */
+ str x30, [x0, MCONTEXT_PC_OFFSET]
+
+ /* Save the current SP */
+ mov x2, sp
+ str x2, [x0, MCONTEXT_SP_OFFSET]
+
+ /* Initialize the pstate. */
+ str xzr, [x0, MCONTEXT_PSTATE_OFFSET]
+
+ /* Figure out where to place the first context extension
+ block. */
+ add x2, x0, #MCONTEXT_EXTENSION_OFFSET
+
+ /* Write the context extension fpsimd header. */
+ mov w3, #(FPSIMD_MAGIC & 0xffff)
+ movk w3, #(FPSIMD_MAGIC >> 16), lsl #16
+ str w3, [x2, #FPSIMD_CONTEXT_MAGIC_OFFSET]
+ mov w3, #FPSIMD_CONTEXT_SIZE
+ str w3, [x2, #FPSIMD_CONTEXT_SIZE_OFFSET]
+
+ /* Fill in the FP SIMD context. */
+ add x3, x2, #(FPSIMD_CONTEXT_VREGS_OFFSET + 8 * SIMD_REGISTER_SIZE)
+ stp d8, d9, [x3], #(2 * SIMD_REGISTER_SIZE)
+ stp d10, d11, [x3], #(2 * SIMD_REGISTER_SIZE)
+ stp d12, d13, [x3], #(2 * SIMD_REGISTER_SIZE)
+ stp d14, d15, [x3], #(2 * SIMD_REGISTER_SIZE)
+
+ add x3, x2, FPSIMD_CONTEXT_FPSR_OFFSET
+
+ mrs x4, fpsr
+ str w4, [x3]
+
+ mrs x4, fpcr
+ str w4, [x3, FPSIMD_CONTEXT_FPCR_OFFSET - FPSIMD_CONTEXT_FPSR_OFFSET]
+
+ /* Write the termination context extension header. */
+ add x2, x2, #FPSIMD_CONTEXT_SIZE
+
+ str xzr, [x2, #FPSIMD_CONTEXT_MAGIC_OFFSET]
+ str xzr, [x2, #FPSIMD_CONTEXT_SIZE_OFFSET]
+
+ /* Grab the signal mask */
+ /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
+ add x2, x0, #UCONTEXT_SIGMASK_OFFSET
+ mov x0, #0 /* SIG_BLOCK */
+ mov x1, #0 /* NULL */
+ mov x3, #(_NSIG / 8)
+ mov x8, #__NR_rt_sigprocmask
+ svc 0
+
+ /* Return x0 for success */
+ mov x0, 0
+ ret
+
+ .cfi_endproc
+ .size breakpad_getcontext, . - breakpad_getcontext
+
+#elif defined(__i386__)
+
+ .text
+ .global breakpad_getcontext
+ .hidden breakpad_getcontext
+ .align 4
+ .type breakpad_getcontext, @function
+
+breakpad_getcontext:
+
+ movl 4(%esp), %eax /* eax = uc */
+
+ /* Save register values */
+ movl %ecx, MCONTEXT_ECX_OFFSET(%eax)
+ movl %edx, MCONTEXT_EDX_OFFSET(%eax)
+ movl %ebx, MCONTEXT_EBX_OFFSET(%eax)
+ movl %edi, MCONTEXT_EDI_OFFSET(%eax)
+ movl %esi, MCONTEXT_ESI_OFFSET(%eax)
+ movl %ebp, MCONTEXT_EBP_OFFSET(%eax)
+
+ movl (%esp), %edx /* return address */
+ lea 4(%esp), %ecx /* exclude return address from stack */
+ mov %edx, MCONTEXT_EIP_OFFSET(%eax)
+ mov %ecx, MCONTEXT_ESP_OFFSET(%eax)
+
+ xorl %ecx, %ecx
+ movw %fs, %cx
+ mov %ecx, MCONTEXT_FS_OFFSET(%eax)
+
+ movl $0, MCONTEXT_EAX_OFFSET(%eax)
+
+ /* Save floating point state to fpregstate, then update
+ * the fpregs pointer to point to it */
+ leal UCONTEXT_FPREGS_MEM_OFFSET(%eax), %ecx
+ fnstenv (%ecx)
+ fldenv (%ecx)
+ mov %ecx, UCONTEXT_FPREGS_OFFSET(%eax)
+
+ /* Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask) */
+ leal UCONTEXT_SIGMASK_OFFSET(%eax), %edx
+ xorl %ecx, %ecx
+ push %edx /* &uc->uc_sigmask */
+ push %ecx /* NULL */
+ push %ecx /* SIGBLOCK == 0 on i386 */
+ call sigprocmask@PLT
+ addl $12, %esp
+
+ movl $0, %eax
+ ret
+
+ .size breakpad_getcontext, . - breakpad_getcontext
+
+#elif defined(__mips__)
+
+// This implementation is inspired by implementation of getcontext in glibc.
+#include <asm-mips/asm.h>
+#include <asm-mips/regdef.h>
+#if _MIPS_SIM == _ABIO32
+#include <asm-mips/fpregdef.h>
+#endif
+
+// from asm-mips/asm.h
+#if _MIPS_SIM == _ABIO32
+#define ALSZ 7
+#define ALMASK ~7
+#define SZREG 4
+#else // _MIPS_SIM != _ABIO32
+#define ALSZ 15
+#define ALMASK ~15
+#define SZREG 8
+#endif
+
+#include <asm/unistd.h> // for __NR_rt_sigprocmask
+
+#define _NSIG8 128 / 8
+#define SIG_BLOCK 1
+
+
+ .text
+LOCALS_NUM = 1 // save gp on stack
+FRAME_SIZE = ((LOCALS_NUM * SZREG) + ALSZ) & ALMASK
+
+GP_FRAME_OFFSET = FRAME_SIZE - (1 * SZREG)
+MCONTEXT_REG_SIZE = 8
+
+#if _MIPS_SIM == _ABIO32
+
+NESTED (breakpad_getcontext, FRAME_SIZE, ra)
+ .mask 0x00000000, 0
+ .fmask 0x00000000, 0
+
+ .set noreorder
+ .cpload t9
+ .set reorder
+
+ move a2, sp
+#define _SP a2
+
+ addiu sp, -FRAME_SIZE
+ .cprestore GP_FRAME_OFFSET
+
+ sw s0, (16 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s1, (17 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s2, (18 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s3, (19 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s4, (20 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s5, (21 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s6, (22 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw s7, (23 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw _SP, (29 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw fp, (30 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw ra, (31 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sw ra, MCONTEXT_PC_OFFSET(a0)
+
+#ifdef __mips_hard_float
+ s.d fs0, (20 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d fs1, (22 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d fs2, (24 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d fs3, (26 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d fs4, (28 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d fs5, (30 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+
+ cfc1 v1, fcr31
+ sw v1, MCONTEXT_FPC_CSR(a0)
+#endif // __mips_hard_float
+
+ /* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
+ li a3, _NSIG8
+ addu a2, a0, UCONTEXT_SIGMASK_OFFSET
+ move a1, zero
+ li a0, SIG_BLOCK
+ li v0, __NR_rt_sigprocmask
+ syscall
+
+ addiu sp, FRAME_SIZE
+ jr ra
+
+END (breakpad_getcontext)
+#else
+
+#ifndef NESTED
+/*
+ * NESTED - declare nested routine entry point
+ */
+#define NESTED(symbol, framesize, rpc) \
+ .globl symbol; \
+ .align 2; \
+ .type symbol,@function; \
+ .ent symbol,0; \
+symbol: .frame sp, framesize, rpc;
+#endif
+
+/*
+ * END - mark end of function
+ */
+#ifndef END
+# define END(function) \
+ .end function; \
+ .size function,.-function
+#endif
+
+/* int getcontext (ucontext_t *ucp) */
+
+NESTED (breakpad_getcontext, FRAME_SIZE, ra)
+ .mask 0x10000000, 0
+ .fmask 0x00000000, 0
+
+ move a2, sp
+#define _SP a2
+ move a3, gp
+#define _GP a3
+
+ daddiu sp, -FRAME_SIZE
+ .cpsetup $25, GP_FRAME_OFFSET, breakpad_getcontext
+
+ /* Store a magic flag. */
+ li v1, 1
+ sd v1, (0 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0) /* zero */
+
+ sd s0, (16 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s1, (17 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s2, (18 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s3, (19 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s4, (20 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s5, (21 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s6, (22 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s7, (23 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd _GP, (28 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd _SP, (29 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd s8, (30 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd ra, (31 * MCONTEXT_REG_SIZE + MCONTEXT_GREGS_OFFSET)(a0)
+ sd ra, MCONTEXT_PC_OFFSET(a0)
+
+#ifdef __mips_hard_float
+ s.d $f24, (24 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f25, (25 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f26, (26 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f27, (27 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f28, (28 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f29, (29 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f30, (30 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+ s.d $f31, (31 * MCONTEXT_REG_SIZE + MCONTEXT_FPREGS_OFFSET)(a0)
+
+ cfc1 v1, $31
+ sw v1, MCONTEXT_FPC_CSR(a0)
+#endif /* __mips_hard_float */
+
+/* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
+ li a3, _NSIG8
+ daddu a2, a0, UCONTEXT_SIGMASK_OFFSET
+ move a1, zero
+ li a0, SIG_BLOCK
+
+ li v0, __NR_rt_sigprocmask
+ syscall
+
+ .cpreturn
+ daddiu sp, FRAME_SIZE
+ move v0, zero
+ jr ra
+
+END (breakpad_getcontext)
+#endif // _MIPS_SIM == _ABIO32
+
+#elif defined(__x86_64__)
+/* The x64 implementation of breakpad_getcontext was derived in part
+ from the implementation of libunwind which requires the following
+ notice. */
+/* libunwind - a platform-independent unwind library
+ Copyright (C) 2008 Google, Inc
+ Contributed by Paul Pluzhnikov <ppluzhnikov@google.com>
+ Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
+
+ .text
+ .global breakpad_getcontext
+ .hidden breakpad_getcontext
+ .align 4
+ .type breakpad_getcontext, @function
+
+breakpad_getcontext:
+ .cfi_startproc
+
+ /* Callee saved: RBX, RBP, R12-R15 */
+ movq %r12, MCONTEXT_GREGS_R12(%rdi)
+ movq %r13, MCONTEXT_GREGS_R13(%rdi)
+ movq %r14, MCONTEXT_GREGS_R14(%rdi)
+ movq %r15, MCONTEXT_GREGS_R15(%rdi)
+ movq %rbp, MCONTEXT_GREGS_RBP(%rdi)
+ movq %rbx, MCONTEXT_GREGS_RBX(%rdi)
+
+ /* Save argument registers (not strictly needed, but setcontext
+ restores them, so don't restore garbage). */
+ movq %r8, MCONTEXT_GREGS_R8(%rdi)
+ movq %r9, MCONTEXT_GREGS_R9(%rdi)
+ movq %rdi, MCONTEXT_GREGS_RDI(%rdi)
+ movq %rsi, MCONTEXT_GREGS_RSI(%rdi)
+ movq %rdx, MCONTEXT_GREGS_RDX(%rdi)
+ movq %rax, MCONTEXT_GREGS_RAX(%rdi)
+ movq %rcx, MCONTEXT_GREGS_RCX(%rdi)
+
+ /* Save fp state (not needed, except for setcontext not
+ restoring garbage). */
+ leaq MCONTEXT_FPREGS_MEM(%rdi),%r8
+ movq %r8, MCONTEXT_FPREGS_PTR(%rdi)
+ fnstenv (%r8)
+ stmxcsr FPREGS_OFFSET_MXCSR(%r8)
+
+ leaq 8(%rsp), %rax /* exclude this call. */
+ movq %rax, MCONTEXT_GREGS_RSP(%rdi)
+
+ movq 0(%rsp), %rax
+ movq %rax, MCONTEXT_GREGS_RIP(%rdi)
+
+ /* Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask) */
+ leaq UCONTEXT_SIGMASK_OFFSET(%rdi), %rdx // arg3
+ xorq %rsi, %rsi // arg2 NULL
+ xorq %rdi, %rdi // arg1 SIGBLOCK == 0
+ call sigprocmask@PLT
+
+ /* Always return 0 for success, even if sigprocmask failed. */
+ xorl %eax, %eax
+ ret
+ .cfi_endproc
+ .size breakpad_getcontext, . - breakpad_getcontext
+
+#else
+#error "This file has not been ported for your CPU!"
+#endif
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-03 14:58:27 +0000