diff options
Diffstat (limited to 'src/arch/x86/linux/syscalls.cc')
-rw-r--r-- | src/arch/x86/linux/syscalls.cc | 107 |
1 files changed, 106 insertions, 1 deletions
diff --git a/src/arch/x86/linux/syscalls.cc b/src/arch/x86/linux/syscalls.cc index 6c44785d2..eacbf5e7b 100644 --- a/src/arch/x86/linux/syscalls.cc +++ b/src/arch/x86/linux/syscalls.cc @@ -122,6 +122,111 @@ archPrctlFunc(SyscallDesc *desc, int callnum, LiveProcess *process, } } +BitUnion32(UserDescFlags) + Bitfield<0> seg_32bit; + Bitfield<2, 1> contents; + Bitfield<3> read_exec_only; + Bitfield<4> limit_in_pages; + Bitfield<5> seg_not_present; + Bitfield<6> useable; +EndBitUnion(UserDescFlags) + +struct UserDesc32 { + uint32_t entry_number; + uint32_t base_addr; + uint32_t limit; + uint32_t flags; +}; + +struct UserDesc64 { + uint32_t entry_number; + uint32_t __padding1; + uint64_t base_addr; + uint32_t limit; + uint32_t flags; +}; + +static SyscallReturn +setThreadArea32Func(SyscallDesc *desc, int callnum, + LiveProcess *process, ThreadContext *tc) +{ + const int minTLSEntry = 6; + const int numTLSEntries = 3; + const int maxTLSEntry = minTLSEntry + numTLSEntries - 1; + + X86LiveProcess *x86lp = dynamic_cast<X86LiveProcess *>(process); + assert(x86lp); + + assert((maxTLSEntry + 1) * sizeof(uint64_t) <= x86lp->gdtSize()); + + TypedBufferArg<UserDesc32> userDesc(process->getSyscallArg(tc, 0)); + TypedBufferArg<uint64_t> + gdt(x86lp->gdtStart() + minTLSEntry * sizeof(uint64_t), + numTLSEntries * sizeof(uint64_t)); + + if (!userDesc.copyIn(tc->getMemPort())) + return -EFAULT; + + if (!gdt.copyIn(tc->getMemPort())) + panic("Failed to copy in GDT for %s.\n", desc->name); + + if (userDesc->entry_number == (uint32_t)(-1)) { + // Find a free TLS entry. + for (int i = 0; i < numTLSEntries; i++) { + if (gdt[i] == 0) { + userDesc->entry_number = i + minTLSEntry; + break; + } + } + // We failed to find one. + if (userDesc->entry_number == (uint32_t)(-1)) + return -ESRCH; + } + + int index = userDesc->entry_number; + + if (index < minTLSEntry || index > maxTLSEntry) + return -EINVAL; + + index -= minTLSEntry; + + // Build the entry we're going to add. + SegDescriptor segDesc = 0; + UserDescFlags flags = userDesc->flags; + + segDesc.limitLow = bits(userDesc->limit, 15, 0); + segDesc.baseLow = bits(userDesc->base_addr, 23, 0); + segDesc.type.a = 1; + if (!flags.read_exec_only) + segDesc.type.w = 1; + if (bits((uint8_t)flags.contents, 0)) + segDesc.type.e = 1; + if (bits((uint8_t)flags.contents, 1)) + segDesc.type.codeOrData = 1; + segDesc.s = 1; + segDesc.dpl = 3; + if (!flags.seg_not_present) + segDesc.p = 1; + segDesc.limitHigh = bits(userDesc->limit, 19, 16); + if (flags.useable) + segDesc.avl = 1; + segDesc.l = 0; + if (flags.seg_32bit) + segDesc.d = 1; + if (flags.limit_in_pages) + segDesc.g = 1; + segDesc.baseHigh = bits(userDesc->base_addr, 31, 24); + + gdt[index] = (uint64_t)segDesc; + + if (!userDesc.copyOut(tc->getMemPort())) + return -EFAULT; + if (!gdt.copyOut(tc->getMemPort())) + panic("Failed to copy out GDT for %s.\n", desc->name); + + return 0; +} + SyscallDesc X86_64LinuxProcess::syscallDescs[] = { /* 0 */ SyscallDesc("read", readFunc), /* 1 */ SyscallDesc("write", writeFunc), @@ -642,7 +747,7 @@ SyscallDesc I386LinuxProcess::syscallDescs[] = { /* 240 */ SyscallDesc("futex", unimplementedFunc), /* 241 */ SyscallDesc("sched_setaffinity", unimplementedFunc), /* 242 */ SyscallDesc("sched_getaffinity", unimplementedFunc), - /* 243 */ SyscallDesc("set_thread_area", unimplementedFunc), + /* 243 */ SyscallDesc("set_thread_area", setThreadArea32Func), /* 244 */ SyscallDesc("get_thread_area", unimplementedFunc), /* 245 */ SyscallDesc("io_setup", unimplementedFunc), /* 246 */ SyscallDesc("io_destroy", unimplementedFunc), |