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Add tests for reading pre-set general purpose register values via PT_…

…GETREGS.

Add new tests verifying that PT_GETREGS provides correct register values
from the underlying program.  The test uses inline assembly in the child program
to set registers to well-known constants, then compares the results obtained
via PT_GETREGS against them.

Reviewed by kamil.
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mgorny committed May 5, 2019
1 parent 6914ed4 commit 7a58d92435a91c159f4f938e4b6dfb3679c66837
Showing with 181 additions and 4 deletions.
  1. +90 −2 tests/lib/libc/sys/t_ptrace_amd64_wait.h
  2. +91 −2 tests/lib/libc/sys/t_ptrace_i386_wait.h
@@ -1,4 +1,4 @@
/* $NetBSD: t_ptrace_amd64_wait.h,v 1.6 2019/02/10 02:13:45 kamil Exp $ */
/* $NetBSD: t_ptrace_amd64_wait.h,v 1.7 2019/05/05 10:04:11 mgorny Exp $ */

/*-
* Copyright (c) 2016, 2017, 2018, 2019 The NetBSD Foundation, Inc.
@@ -111,11 +111,99 @@ ATF_TC_BODY(x86_64_regs1, tc)
TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
}

ATF_TC(x86_64_regs_gp_read);
ATF_TC_HEAD(x86_64_regs_gp_read, tc)
{
atf_tc_set_md_var(tc, "descr",
"Set general-purpose reg values from debugged program and read "
"them via PT_GETREGS, comparing values against expected.");
}

ATF_TC_BODY(x86_64_regs_gp_read, tc)
{
const int exitval = 5;
const int sigval = SIGTRAP;
pid_t child, wpid;
#if defined(TWAIT_HAVE_STATUS)
int status;
#endif
struct reg gpr;

const uint64_t rax = 0x0001020304050607;
const uint64_t rbx = 0x1011121314151617;
const uint64_t rcx = 0x2021222324252627;
const uint64_t rdx = 0x3031323334353637;
const uint64_t rsi = 0x4041424344454647;
const uint64_t rdi = 0x5051525354555657;
const uint64_t rsp = 0x6061626364656667;
const uint64_t rbp = 0x7071727374757677;

DPRINTF("Before forking process PID=%d\n", getpid());
SYSCALL_REQUIRE((child = fork()) != -1);
if (child == 0) {
DPRINTF("Before calling PT_TRACE_ME from child %d\n", getpid());
FORKEE_ASSERT(ptrace(PT_TRACE_ME, 0, NULL, 0) != -1);

DPRINTF("Before running assembly from child\n");

__asm__ __volatile__(
/* rbp & rbp are a bit tricky, we must not clobber them */
"movq %%rsp, %%r8\n\t"
"movq %%rbp, %%r9\n\t"
"movq %6, %%rsp\n\t"
"movq %7, %%rbp\n\t"
"\n\t"
"int3\n\t"
"\n\t"
"movq %%r8, %%rsp\n\t"
"movq %%r9, %%rbp\n\t"
:
: "a"(rax), "b"(rbx), "c"(rcx), "d"(rdx), "S"(rsi), "D"(rdi),
"i"(rsp), "i"(rbp)
: "%r8", "%r9"
);

DPRINTF("Before exiting of the child process\n");
_exit(exitval);
}
DPRINTF("Parent process PID=%d, child's PID=%d\n", getpid(), child);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);

validate_status_stopped(status, sigval);

DPRINTF("Call GETREGS for the child process\n");
SYSCALL_REQUIRE(ptrace(PT_GETREGS, child, &gpr, 0) != -1);

ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RAX], rax);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RBX], rbx);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RCX], rcx);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RDX], rdx);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RSI], rsi);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RDI], rdi);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RSP], rsp);
ATF_CHECK_EQ((uint64_t)gpr.regs[_REG_RBP], rbp);

DPRINTF("Before resuming the child process where it left off and "
"without signal to be sent\n");
SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);

validate_status_exited(status, exitval);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
}

/// ----------------------------------------------------------------------------


#define ATF_TP_ADD_TCS_PTRACE_WAIT_AMD64() \
ATF_TP_ADD_TC_HAVE_GPREGS(tp, x86_64_regs1);
ATF_TP_ADD_TC_HAVE_GPREGS(tp, x86_64_regs1); \
ATF_TP_ADD_TC_HAVE_GPREGS(tp, x86_64_regs_gp_read);
#else
#define ATF_TP_ADD_TCS_PTRACE_WAIT_AMD64()
#endif
@@ -1,4 +1,4 @@
/* $NetBSD: t_ptrace_i386_wait.h,v 1.3 2019/02/10 02:13:45 kamil Exp $ */
/* $NetBSD: t_ptrace_i386_wait.h,v 1.4 2019/05/05 10:04:11 mgorny Exp $ */

/*-
* Copyright (c) 2016, 2017, 2018, 2019 The NetBSD Foundation, Inc.
@@ -100,8 +100,97 @@ ATF_TC_BODY(i386_regs1, tc)
DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
}

ATF_TC(i386_regs_gp_read);
ATF_TC_HEAD(i386_regs_gp_read, tc)
{
atf_tc_set_md_var(tc, "descr",
"Set general-purpose reg values from debugged program and read "
"them via PT_GETREGS, comparing values against expected.");
}

ATF_TC_BODY(i386_regs_gp_read, tc)
{
const int exitval = 5;
const int sigval = SIGTRAP;
pid_t child, wpid;
#if defined(TWAIT_HAVE_STATUS)
int status;
#endif
struct reg gpr;

const uint32_t eax = 0x00010203;
const uint32_t ebx = 0x10111213;
const uint32_t ecx = 0x20212223;
const uint32_t edx = 0x30313233;
const uint32_t esi = 0x40414243;
const uint32_t edi = 0x50515253;
const uint32_t esp = 0x60616263;
const uint32_t ebp = 0x70717273;

DPRINTF("Before forking process PID=%d\n", getpid());
SYSCALL_REQUIRE((child = fork()) != -1);
if (child == 0) {
DPRINTF("Before calling PT_TRACE_ME from child %d\n", getpid());
FORKEE_ASSERT(ptrace(PT_TRACE_ME, 0, NULL, 0) != -1);

DPRINTF("Before running assembly from child\n");

__asm__ __volatile__(
/* ebp & ebp are a bit tricky, we must not clobber them */
"movd %%esp, %%mm0\n\t"
"movd %%ebp, %%mm1\n\t"
"movd %6, %%esp\n\t"
"movd %7, %%ebp\n\t"
"\n\t"
"int3\n\t"
"\n\t"
"movd %%mm0, %%esp\n\t"
"movd %%mm1, %%ebp\n\t"
:
: "a"(eax), "b"(ebx), "c"(ecx), "d"(edx), "S"(esi), "D"(edi),
"y"(esp), "y"(ebp)
: "%mm0", "%mm1"
);

DPRINTF("Before exiting of the child process\n");
_exit(exitval);
}
DPRINTF("Parent process PID=%d, child's PID=%d\n", getpid(), child);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);

validate_status_stopped(status, sigval);

DPRINTF("Call GETREGS for the child process\n");
SYSCALL_REQUIRE(ptrace(PT_GETREGS, child, &gpr, 0) != -1);

ATF_CHECK_EQ((uint32_t)gpr.r_eax, eax);
ATF_CHECK_EQ((uint32_t)gpr.r_ebx, ebx);
ATF_CHECK_EQ((uint32_t)gpr.r_ecx, ecx);
ATF_CHECK_EQ((uint32_t)gpr.r_edx, edx);
ATF_CHECK_EQ((uint32_t)gpr.r_esi, esi);
ATF_CHECK_EQ((uint32_t)gpr.r_edi, edi);
ATF_CHECK_EQ((uint32_t)gpr.r_esp, esp);
ATF_CHECK_EQ((uint32_t)gpr.r_ebp, ebp);

DPRINTF("Before resuming the child process where it left off and "
"without signal to be sent\n");
SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);

validate_status_exited(status, exitval);

DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
}

#define ATF_TP_ADD_TCS_PTRACE_WAIT_I386() \
ATF_TP_ADD_TC_HAVE_GPREGS(tp, i386_regs1);
ATF_TP_ADD_TC_HAVE_GPREGS(tp, i386_regs1); \
ATF_TP_ADD_TC_HAVE_GPREGS(tp, i386_regs_gp_read);
#else
#define ATF_TP_ADD_TCS_PTRACE_WAIT_I386()
#endif

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