this repo has no description
Some initial work on ptrace/SIGEXC support
+208
-21
+7
-1
src/kernel/emulation/linux/CMakeLists.txt
+7
-1
src/kernel/emulation/linux/CMakeLists.txt
···
15
15
16
16
17
17
include_directories(${CMAKE_SOURCE_DIR}/src/startup)
18
-
include_directories(${CMAKE_CURRENT_SOURCE_DIR})
18
+
19
+
# include src/startup for rtsig.h
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include_directories(${CMAKE_CURRENT_SOURCE_DIR}
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${CMAKE_BINARY_DIR}/src/startup
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+
)
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set(emulation_sources
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elfcalls_wrapper.c
···
132
136
signal/sigprocmask.c
133
137
signal/sig_restorer.S
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signal/sigsuspend.c
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+
signal/sigexc.c
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misc/ptrace.c
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misc/getentropy.c
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misc/syscall.c
···
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add_library(emulation OBJECT ${emulation_sources})
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add_library(emulation_dyld OBJECT ${emulation_sources})
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set_target_properties(emulation_dyld PROPERTIES COMPILE_FLAGS "-ffunction-sections -DVARIANT_DYLD")
299
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add_dependencies(emulation rtsig_h)
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make_fat(emulation)
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make_fat(emulation_dyld)
+2
src/kernel/emulation/linux/mach/mach_traps.c
+2
src/kernel/emulation/linux/mach/mach_traps.c
+13
-14
src/kernel/emulation/linux/process/wait4.c
+13
-14
src/kernel/emulation/linux/process/wait4.c
···
3
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#include "../errno.h"
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#include "../signal/duct_signals.h"
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#include "../misc/ptrace.h"
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#include "../mach/lkm.h"
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#include "../../../../lkm/api.h"
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#include <sys/signal.h>
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#include <stddef.h>
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#include <linux-syscalls/linux.h>
···
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signal = signum_linux_to_bsd(signal);
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*status = (*status & 0x7f) | (signal << 8);
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switch (signal)
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if (lkm_call(NR_get_tracer, (void*)(long) ret) == getpid())
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{
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case SIGCONT:
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case SIGSTOP:
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case SIGTSTP:
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case SIGTTIN:
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case SIGTTOU:
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// It is standard behavior that these signals stop (resume) the process
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break;
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default:
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// We are probably ptracing the target process.
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// Allow the execution to continue so that the ptraced process can translate
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// the signal into a Mach message.
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sys_ptrace(PT_CONTINUE, ret, NULL, signal);
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goto restart;
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// We are ptracing the target process.
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// Allow the execution to continue so that the ptraced process can translate
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// the signal into a Mach message.
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if (signal == SIGSTOP)
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{
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// TODO: notify target process it has been SIGSTOP'ed via sigqueue
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}
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sys_ptrace(PT_CONTINUE, ret, NULL, signal);
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goto restart;
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}
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}
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-1
src/kernel/emulation/linux/signal/duct_signals.h
-1
src/kernel/emulation/linux/signal/duct_signals.h
+13
-5
src/kernel/emulation/linux/signal/sigaction.c
+13
-5
src/kernel/emulation/linux/signal/sigaction.c
···
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#include "../simple.h"
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#include <linux-syscalls/linux.h>
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#include <stddef.h>
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#include "sigexc.h"
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#include "../../../../../platform-include/sys/errno.h"
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9
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static void handler_linux_to_bsd(int linux_signum, struct linux_siginfo* info, void* ctxt);
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static int sigflags_bsd_to_linux(int flags);
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static int sigflags_linux_to_bsd(int flags);
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extern void sig_restorer(void);
···
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// Libc uses only one trampoline
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void (*sa_tramp)(void*, int, int, struct bsd_siginfo*, void*) = 0;
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static bsd_sig_handler* sig_handlers[32];
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bsd_sig_handler* sig_handlers[32];
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int sig_flags[32];
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unsigned int sig_masks[32];
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long sys_sigaction(int signum, const struct bsd___sigaction* nsa, struct bsd_sigaction* osa)
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{
···
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if (nsa != NULL)
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{
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sa_tramp = nsa->sa_tramp;
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if (nsa->sa_sigaction != SIG_DFL && nsa->sa_sigaction != SIG_IGN
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if (darling_am_i_ptraced())
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{
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sa.sa_sigaction = &sigexc_handler;
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}
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else if (nsa->sa_sigaction != SIG_DFL && nsa->sa_sigaction != SIG_IGN
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&& nsa->sa_sigaction != SIG_ERR)
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{
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sa.sa_sigaction = &handler_linux_to_bsd;
···
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osa->sa_flags = sigflags_linux_to_bsd(olsa.sa_flags);
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}
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-
if (nsa != NULL)
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if (nsa != NULL && ret >= 0)
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{
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// __simple_printf("Saving handler for signal %d: %d\n", linux_signum, nsa->sa_sigaction);
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sig_handlers[linux_signum] = nsa->sa_sigaction;
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sig_flags[linux_signum] = sa.sa_flags;
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sig_masks[linux_signum] = sa.sa_mask;
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}
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return 0;
···
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#undef copyreg
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}
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-
static void handler_linux_to_bsd(int linux_signum, struct linux_siginfo* info, void* ctxt)
131
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void handler_linux_to_bsd(int linux_signum, struct linux_siginfo* info, void* ctxt)
124
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{
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int bsd_signum;
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struct bsd_siginfo binfo;
+6
src/kernel/emulation/linux/signal/sigaction.h
+6
src/kernel/emulation/linux/signal/sigaction.h
···
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union
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{
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int _pad[__SI_PAD_SIZE];
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unsigned long si_value;
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};
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};
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···
193
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unsigned long uc_mcsize;
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struct bsd_mcontext* uc_mcontext;
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};
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+
198
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void handler_linux_to_bsd(int linux_signum, struct linux_siginfo* info, void* ctxt);
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extern bsd_sig_handler* sig_handlers[32];
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extern int sig_flags[32];
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extern unsigned int sig_masks[32];
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#endif
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+113
src/kernel/emulation/linux/signal/sigexc.c
+113
src/kernel/emulation/linux/signal/sigexc.c
···
1
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#include "sigexc.h"
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#include "../base.h"
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#include <stddef.h>
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#include <linux-syscalls/linux.h>
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// Support for Darwin debugging.
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+
// Unlike other Unix-like systems, macOS doesn't use wait() to handle events in the debugged process.
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+
9
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static bool am_i_ptraced = false;
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static void handle_rt_signal(int signum);
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extern void sig_restorer(void);
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void darling_sigexc_uninstall(void);
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void sigrt_handler(int signum, struct linux_siginfo* info, void* ctxt);
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void sigexc_setup(void)
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{
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// Setup handler for SIGNAL_SIGEXC_TOGGLE and SIGNAL_SIGEXC_THUPDATE
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handle_rt_signal(SIGNAL_SIGEXC_TOGGLE);
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handle_rt_signal(SIGNAL_SIGEXC_THUPDATE);
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}
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static void handle_rt_signal(int signum)
23
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{
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struct linux_sigaction sa;
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sa.sa_sigaction = sigrt_handler;
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sa.sa_mask = 0;
27
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sa.sa_flags = LINUX_SA_RESTORER | LINUX_SA_SIGINFO | LINUX_SA_RESTART;
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sa.sa_restorer = sig_restorer;
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LINUX_SYSCALL(__NR_rt_sigaction, signum,
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&sa, NULL,
32
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sizeof(sa.sa_mask));
33
+
}
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+
35
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bool darling_am_i_ptraced(void)
36
+
{
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return am_i_ptraced;
38
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}
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+
40
+
void sigrt_handler(int signum, struct linux_siginfo* info, void* ctxt)
41
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{
42
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if (signum == SIGNAL_SIGEXC_TOGGLE)
43
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{
44
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if (info->si_value == SIGRT_MAGIC_ENABLE_SIGEXC)
45
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{
46
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am_i_ptraced = true;
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darling_sigexc_self();
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}
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else if (info->si_value == SIGRT_MAGIC_DISABLE_SIGEXC)
50
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{
51
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am_i_ptraced = false;
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darling_sigexc_uninstall();
53
+
}
54
+
}
55
+
else if (signum == SIGNAL_SIGEXC_THUPDATE)
56
+
{
57
+
// TODO: Change how a pending signal is handled
58
+
// Use TLS?
59
+
if (!am_i_ptraced)
60
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return;
61
+
}
62
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}
63
+
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+
void darling_sigexc_self(void)
65
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{
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+
// Make sigexc_handler the handler for all signals in the process
67
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for (int i = 1; i <= 31; i++)
68
+
{
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struct linux_sigaction sa;
70
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sa.sa_sigaction = sigrt_handler;
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sa.sa_mask = sig_masks[i];
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sa.sa_flags = LINUX_SA_RESTORER | LINUX_SA_SIGINFO | LINUX_SA_RESTART;
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+
sa.sa_restorer = sig_restorer;
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+
75
+
LINUX_SYSCALL(__NR_rt_sigaction, i,
76
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&sa, NULL,
77
+
sizeof(sa.sa_mask));
78
+
}
79
+
}
80
+
void darling_sigexc_uninstall(void)
81
+
{
82
+
for (int i = 1; i <= 31; i++)
83
+
{
84
+
struct linux_sigaction sa;
85
+
86
+
if (sig_handlers[i] == SIG_DFL || sig_handlers[i] != SIG_IGN
87
+
|| sig_handlers[i] != SIG_ERR)
88
+
{
89
+
sa.sa_sigaction = (linux_sig_handler*) sig_handlers[i];
90
+
}
91
+
else
92
+
sa.sa_sigaction = &handler_linux_to_bsd;
93
+
94
+
sa.sa_mask = sig_masks[i];
95
+
sa.sa_flags = sig_flags[i];
96
+
sa.sa_restorer = sig_restorer;
97
+
98
+
LINUX_SYSCALL(__NR_rt_sigaction, i,
99
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&sa, NULL,
100
+
sizeof(sa.sa_mask));
101
+
}
102
+
}
103
+
104
+
void sigexc_handler(int linux_signum, struct linux_siginfo* info, void* ctxt)
105
+
{
106
+
// SIGSEGV + SIGBUS -> EXC_BAD_ACCESS
107
+
// SIGTRAP -> EXC_BREAKPOINT
108
+
// * -> EXC_SOFTWARE with EXC_SOFT_SIGNAL (e.g. SIGSTOP
109
+
if (darling_am_i_ptraced())
110
+
{
111
+
}
112
+
}
113
+
+25
src/kernel/emulation/linux/signal/sigexc.h
+25
src/kernel/emulation/linux/signal/sigexc.h
···
1
+
#ifndef _SIGEXC_H
2
+
#define _SIGEXC_H
3
+
#include <stdbool.h>
4
+
#include "rtsig.h"
5
+
#include "sigaction.h"
6
+
7
+
#define SIGNAL_SIGEXC_TOGGLE LINUX_SIGRTMIN
8
+
#define SIGNAL_SIGEXC_THUPDATE (LINUX_SIGRTMIN + 1)
9
+
10
+
#define SIGRT_MAGIC_ENABLE_SIGEXC 0xdebdeb01
11
+
#define SIGRT_MAGIC_DISABLE_SIGEXC 0xdebdeb00
12
+
#define SIGRT_
13
+
14
+
// Initializes this module
15
+
void sigexc_setup(void);
16
+
17
+
// Is this process currently traced by a debugger?
18
+
bool darling_am_i_ptraced(void);
19
+
20
+
// for PT_SIGEXC to handle this operation synchronously
21
+
void darling_sigexc_self(void);
22
+
void sigexc_handler(int linux_signum, struct linux_siginfo* info, void* ctxt);
23
+
24
+
#endif
25
+
+4
src/startup/CMakeLists.txt
+4
src/startup/CMakeLists.txt
···
59
59
add_executable(print_wrapped_elf wrapgen/print_wrapped_elf.cpp)
60
60
endif (DEFINED WITH_PRINT_WRAPPED_ELF)
61
61
62
+
add_executable(rtsig rtsig.c)
63
+
add_custom_command(OUTPUT rtsig.h DEPENDS rtsig COMMAND ${CMAKE_CURRENT_BINARY_DIR}/rtsig rtsig.h COMMENT "Determining available RT signals")
64
+
add_custom_target(rtsig_h DEPENDS rtsig.h)
65
+
+25
src/startup/rtsig.c
+25
src/startup/rtsig.c
···
1
+
#include <signal.h>
2
+
#include <stdio.h>
3
+
4
+
// Determine RT signal ranges without polluting the build environment with Linux system headers
5
+
int main(int argc, char** argv)
6
+
{
7
+
FILE* output = stdout;
8
+
9
+
if (argc > 1)
10
+
{
11
+
output = fopen(argv[1], "w");
12
+
if (!output)
13
+
{
14
+
perror("fopen");
15
+
return 1;
16
+
}
17
+
}
18
+
19
+
fprintf(output, "#define LINUX_SIGRTMIN %d\n", SIGRTMIN);
20
+
fprintf(output, "#define LINUX_SIGRTMAX %d\n", SIGRTMAX);
21
+
22
+
fclose(output);
23
+
return 0;
24
+
}
25
+