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store in fs:0 the address pointed to by fs itself

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- defined in the x86_64 ABI because you cannot easily get the address
  pointed to by fs without reading fs' MSR
This commit is contained in:
Stefan Lankes 2017-02-12 23:53:58 +01:00
parent ee703ddaf2
commit 7e8549b8fa
1 changed files with 5 additions and 2 deletions
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7
kernel/tasks.c
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@ -334,11 +334,12 @@ int init_tls(void)
// do we have a thread local storage?
if (((size_t) &tls_end - (size_t) &tls_start) > 0) {
char* tls_addr = NULL;
size_t fs;
curr_task->tls_addr = (size_t) &tls_start;
curr_task->tls_size = (size_t) &tls_end - (size_t) &tls_start;
tls_addr = kmalloc(curr_task->tls_size + TLS_OFFSET);
tls_addr = kmalloc(curr_task->tls_size + TLS_OFFSET + sizeof(size_t));
if (BUILTIN_EXPECT(!tls_addr, 0)) {
LOG_ERROR("load_task: heap is missing!\n");
return -ENOMEM;
@ -346,9 +347,11 @@ int init_tls(void)
memset(tls_addr, 0x00, TLS_OFFSET);
memcpy((void*) (tls_addr+TLS_OFFSET), (void*) curr_task->tls_addr, curr_task->tls_size);
fs = (size_t) tls_addr + curr_task->tls_size + TLS_OFFSET;
*((size_t*)fs) = fs;
// set fs register to the TLS segment
set_tls((size_t) tls_addr + curr_task->tls_size + TLS_OFFSET);
set_tls(fs);
LOG_INFO("TLS of task %d on core %d starts at 0x%zx (TLS)\n", curr_task->id, CORE_ID, tls_addr + TLS_OFFSET);
} else set_tls(0); // no TLS => clear fs register