diff options
Diffstat (limited to 'sysdeps/mach')
| -rw-r--r-- | sysdeps/mach/hurd/fork.c | 7 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/i386/tls.h | 53 | ||||
| -rw-r--r-- | sysdeps/mach/hurd/i386/trampoline.c | 2 | ||||
| -rw-r--r-- | sysdeps/mach/i386/thread_state.h | 13 | ||||
| -rw-r--r-- | sysdeps/mach/thread_state.h | 6 |
5 files changed, 73 insertions, 8 deletions
diff --git a/sysdeps/mach/hurd/fork.c b/sysdeps/mach/hurd/fork.c index b55eecffc6..cc322ebee5 100644 --- a/sysdeps/mach/hurd/fork.c +++ b/sysdeps/mach/hurd/fork.c @@ -507,6 +507,11 @@ __fork (void) #endif MACHINE_THREAD_STATE_SET_PC (&state, (unsigned long int) _hurd_msgport_receive); + + /* Do special signal thread setup for TLS if needed. */ + if (err = _hurd_tls_fork (sigthread, _hurd_msgport_thread, &state)) + LOSE; + if (err = __thread_set_state (sigthread, MACHINE_THREAD_STATE_FLAVOR, (natural_t *) &state, statecount)) LOSE; @@ -517,7 +522,7 @@ __fork (void) _hurd_longjmp_thread_state (&state, env, 1); /* Do special thread setup for TLS if needed. */ - if (err = _hurd_tls_fork (thread, &state)) + if (err = _hurd_tls_fork (thread, ss->thread, &state)) LOSE; if (err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR, diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h index b194a49e34..4c78685045 100644 --- a/sysdeps/mach/hurd/i386/tls.h +++ b/sysdeps/mach/hurd/i386/tls.h @@ -52,6 +52,15 @@ typedef struct #define TLS_TCB_AT_TP 1 #define TLS_DTV_AT_TP 0 +/* Alignment requirement for TCB. + + Some processors such as Intel Atom pay a big penalty on every + access using a segment override if that segment's base is not + aligned to the size of a cache line. (See Intel 64 and IA-32 + Architectures Optimization Reference Manual, section 13.3.3.3, + "Segment Base".) On such machines, a cache line is 64 bytes. */ +#define TCB_ALIGNMENT 64 + #ifndef __ASSEMBLER__ /* Use i386-specific RPCs to arrange that %gs segment register prefix @@ -78,6 +87,7 @@ typedef struct | (((unsigned int) (tcb)) & 0xff000000) /* base 24..31 */ \ } +# define HURD_SEL_LDT(sel) (__builtin_expect((sel) & 4, 0)) static inline const char * __attribute__ ((unused)) _hurd_tls_init (tcbhead_t *tcb) @@ -141,9 +151,40 @@ _hurd_tls_init (tcbhead_t *tcb) # include <mach/machine/thread_status.h> -/* Set up TLS in the new thread of a fork child, copying from our own. */ -static inline error_t __attribute__ ((unused)) -_hurd_tls_fork (thread_t child, struct i386_thread_state *state) +/* Set up TLS in the new thread of a fork child, copying from the original. */ +static inline kern_return_t __attribute__ ((unused)) +_hurd_tls_fork (thread_t child, thread_t orig, struct i386_thread_state *state) +{ + /* Fetch the selector set by _hurd_tls_init. */ + int sel; + asm ("mov %%gs, %w0" : "=q" (sel) : "0" (0)); + if (sel == state->ds) /* _hurd_tls_init was never called. */ + return 0; + + struct descriptor desc, *_desc = &desc; + error_t err; + unsigned int count = 1; + + if (HURD_SEL_LDT(sel)) + err = __i386_get_ldt (orig, sel, 1, &_desc, &count); + else + err = __i386_get_gdt (orig, sel, &desc); + + assert_perror (err); + if (err) + return err; + + if (HURD_SEL_LDT(sel)) + err = __i386_set_ldt (child, sel, &desc, 1); + else + err = __i386_set_gdt (child, &sel, desc); + + state->gs = sel; + return err; +} + +static inline kern_return_t __attribute__ ((unused)) +_hurd_tls_new (thread_t child, struct i386_thread_state *state, tcbhead_t *tcb) { /* Fetch the selector set by _hurd_tls_init. */ int sel; @@ -151,11 +192,13 @@ _hurd_tls_fork (thread_t child, struct i386_thread_state *state) if (sel == state->ds) /* _hurd_tls_init was never called. */ return 0; - tcbhead_t *const tcb = THREAD_SELF; HURD_TLS_DESC_DECL (desc, tcb); error_t err; - if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */ + tcb->tcb = tcb; + tcb->self = child; + + if (HURD_SEL_LDT(sel)) err = __i386_set_ldt (child, sel, &desc, 1); else err = __i386_set_gdt (child, &sel, desc); diff --git a/sysdeps/mach/hurd/i386/trampoline.c b/sysdeps/mach/hurd/i386/trampoline.c index d240ca72a4..0c68759f42 100644 --- a/sysdeps/mach/hurd/i386/trampoline.c +++ b/sysdeps/mach/hurd/i386/trampoline.c @@ -62,7 +62,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, sizeof (state->basic)); memcpy (&state->fpu, &ss->context->sc_i386_float_state, sizeof (state->fpu)); - state->set |= (1 << i386_THREAD_STATE) | (1 << i386_FLOAT_STATE); + state->set |= (1 << i386_REGS_SEGS_STATE) | (1 << i386_FLOAT_STATE); } } diff --git a/sysdeps/mach/i386/thread_state.h b/sysdeps/mach/i386/thread_state.h index 56d91dfdb7..be3c8a9cee 100644 --- a/sysdeps/mach/i386/thread_state.h +++ b/sysdeps/mach/i386/thread_state.h @@ -21,7 +21,10 @@ #include <mach/machine/thread_status.h> -#define MACHINE_THREAD_STATE_FLAVOR i386_THREAD_STATE +/* This lets the kernel define segments for a new thread. */ +#define MACHINE_NEW_THREAD_STATE_FLAVOR i386_THREAD_STATE +/* This makes the kernel load our segments descriptors. */ +#define MACHINE_THREAD_STATE_FLAVOR i386_REGS_SEGS_STATE #define MACHINE_THREAD_STATE_COUNT i386_THREAD_STATE_COUNT #define machine_thread_state i386_thread_state @@ -30,6 +33,14 @@ #define SP uesp #define SYSRETURN eax +#define MACHINE_THREAD_STATE_FIX_NEW(ts) do { \ + asm ("mov %%cs, %w0" : "=q" ((ts)->cs)); \ + asm ("mov %%ds, %w0" : "=q" ((ts)->ds)); \ + asm ("mov %%es, %w0" : "=q" ((ts)->es)); \ + asm ("mov %%fs, %w0" : "=q" ((ts)->fs)); \ + asm ("mov %%gs, %w0" : "=q" ((ts)->gs)); \ +} while(0) + struct machine_thread_all_state { int set; /* Mask of bits (1 << FLAVOR). */ diff --git a/sysdeps/mach/thread_state.h b/sysdeps/mach/thread_state.h index bc4feefe01..2e3a10cbcb 100644 --- a/sysdeps/mach/thread_state.h +++ b/sysdeps/mach/thread_state.h @@ -38,6 +38,12 @@ #endif #endif +/* This copies architecture-specific bits from the current thread to the new + thread state. */ +#ifndef MACHINE_THREAD_STATE_FIX_NEW +# define MACHINE_THREAD_STATE_FIX_NEW(ts) +#endif + /* These functions are of use in machine-dependent signal trampoline implementations. */ |