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X86: Implement the 32 bit set_thread_area system call.

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Gabe Black 2009-02-27 09:23:42 -08:00
parent 1786f20058
commit 9491debaa6
1 changed files with 106 additions and 1 deletions
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107
src/arch/x86/linux/syscalls.cc
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@ -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),