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UserspaceEmulator: Handle PerfEvent syscalls

We only froward String setting and FlagPost creation for now, due to the
other performance events being nonsensical to forward.
We also record these signposts in the optionally generated profile.
This commit is contained in:
Hediadyoin1 2021-08-20 17:09:23 +02:00 committed by Brian Gianforcaro
parent 045461b7cb
commit bce3bf9f1e
3 changed files with 63 additions and 7 deletions

View file

@ -10,6 +10,7 @@
#include <AK/Debug.h>
#include <AK/FileStream.h>
#include <AK/Format.h>
#include <alloca.h>
#include <fcntl.h>
#include <sched.h>
#include <serenity.h>
@ -75,6 +76,10 @@ u32 Emulator::virt_syscall(u32 function, u32 arg1, u32 arg2, u32 arg3)
return virt$profiling_enable(arg1);
case SC_profiling_disable:
return virt$profiling_disable(arg1);
case SC_perf_event:
return virt$perf_event((int)arg1, arg2, arg3);
case SC_perf_register_string:
return virt$perf_register_string(arg1, arg2);
case SC_disown:
return virt$disown(arg1);
case SC_purge:
@ -248,8 +253,6 @@ u32 Emulator::virt_syscall(u32 function, u32 arg1, u32 arg2, u32 arg3)
case SC_futex:
return virt$futex(arg1);
case SC_map_time_page:
case SC_perf_register_string:
case SC_perf_event:
return -ENOSYS;
default:
reportln("\n=={}== \033[31;1mUnimplemented syscall: {}\033[0m, {:p}", getpid(), Syscall::to_string((Syscall::Function)function), function);
@ -283,6 +286,37 @@ int Emulator::virt$profiling_disable(pid_t pid)
return syscall(SC_profiling_disable, pid);
}
FlatPtr Emulator::virt$perf_event(int event, FlatPtr arg1, FlatPtr arg2)
{
if (event == PERF_EVENT_SIGNPOST) {
if (is_profiling()) {
if (profiler_string_id_map().size() > arg1)
emit_profile_event(profile_stream(), "signpost", String::formatted("\"arg1\": {}, \"arg2\": {}", arg1, arg2));
syscall(SC_perf_event, PERF_EVENT_SIGNPOST, profiler_string_id_map().at(arg1), arg2);
} else {
syscall(SC_perf_event, PERF_EVENT_SIGNPOST, arg1, arg2);
}
return 0;
}
return -ENOSYS;
}
FlatPtr Emulator::virt$perf_register_string(FlatPtr string, size_t size)
{
char* buffer = (char*)alloca(size + 4);
// FIXME: not nice, but works
__builtin_memcpy(buffer, "UE: ", 4);
mmu().copy_from_vm((buffer + 4), string, size);
auto ret = (int)syscall(SC_perf_register_string, buffer, size + 4);
if (ret >= 0 && is_profiling()) {
profiler_strings().append(make<String>(StringView { buffer + 4, size }));
profiler_string_id_map().append(ret);
ret = profiler_string_id_map().size() - 1;
}
return ret;
}
int Emulator::virt$disown(pid_t pid)
{
return syscall(SC_disown, pid);