diff options
Diffstat (limited to 'sysdeps/mach/hurd/x86/trampoline.c')
| -rw-r--r-- | sysdeps/mach/hurd/x86/trampoline.c | 105 |
1 files changed, 84 insertions, 21 deletions
diff --git a/sysdeps/mach/hurd/x86/trampoline.c b/sysdeps/mach/hurd/x86/trampoline.c index 8e2890f..6f23c56 100644 --- a/sysdeps/mach/hurd/x86/trampoline.c +++ b/sysdeps/mach/hurd/x86/trampoline.c @@ -26,7 +26,11 @@ #include "hurdfault.h" #include <intr-msg.h> #include <sys/ucontext.h> - +#ifdef __x86_64__ +#include <mach/x86_64/mach_i386.h> +#else +#include <mach/i386/mach_i386.h> +#endif /* Fill in a siginfo_t structure for SA_SIGINFO-enabled handlers. */ static void fill_siginfo (siginfo_t *si, int signo, @@ -106,6 +110,7 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action void firewall (void); void *sigsp; struct sigcontext *scp; + vm_size_t xstate_size; struct { union @@ -145,6 +150,14 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action struct hurd_userlink link; ucontext_t ucontext; siginfo_t siginfo; +#ifdef __x86_64__ + char _pad2[56]; +#else + char _pad2[20]; +#endif + char xstate[]; + /* Don't add anything after xstate, as it's dynamically + sized. */ } *stackframe; #ifdef __x86_64__ @@ -170,6 +183,17 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action if (! machine_get_basic_state (ss->thread, state)) return NULL; + /* Initialize the size of the CPU extended state, to be saved during + * signal handling */ +#ifdef i386_XFLOAT_STATE + _Static_assert ((sizeof(*stackframe) + sizeof(struct i386_xfloat_state)) % 64 == 0, + "stackframe size must be multiple of 64-byte minus " + "sizeof(struct i386_xfloat_state), please adjust _pad2"); + + if (__i386_get_xstate_size(__mach_host_self(), &xstate_size)) +#endif + xstate_size = 0; + /* Save the original SP in the gratuitous `esp' slot. We may need to reset the SP (the `uesp' slot) to avoid clobbering an interrupted RPC frame. */ @@ -196,14 +220,21 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action #endif } - /* Push the arguments to call `trampoline' on the stack. */ - sigsp -= sizeof (*stackframe); -#ifdef __x86_64__ - /* Align SP at 16 bytes. Coupled with the fact that sigreturn_addr is - 16-byte aligned within the stackframe struct, this ensures that it ends - up on a 16-byte aligned address, as required by the ABI. */ - sigsp = (void *) ((uintptr_t) sigsp & ~15UL); -#endif + /* Push the arguments to call `trampoline' on the stack. + * The extended state might have a variable size depending on the platform, + * so we dynamically allocate it on the stack frame.*/ + sigsp -= sizeof (*stackframe) + xstate_size; + + /* Align SP at 64 bytes. This is needed for two reasons: + * - sigreturn_addr is 16-byte aligned within the stackframe + * struct, and this ensures that it ends up on a 16-byte aligned + * address, as required by the ABI. + * - the XSAVE state needs to be aligned at 64 bytes (on both i386 and + * x86_64), so we align the stackframe also at 64 bytes and add the + * required padding at the end, see the _pad2 field. + */ + sigsp = (void *) ((uintptr_t) sigsp & ~63UL); + stackframe = sigsp; if (_hurdsig_catch_memory_fault (stackframe)) @@ -248,14 +279,40 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action memcpy (&scp->sc_i386_thread_state, &state->basic, sizeof (state->basic)); - /* struct sigcontext is laid out so that starting at sc_fpkind mimics - a struct i386_float_state. */ - _Static_assert (offsetof (struct sigcontext, sc_i386_float_state) - % __alignof__ (struct i386_float_state) == 0, - "sc_i386_float_state layout mismatch"); - ok = machine_get_state (ss->thread, state, i386_FLOAT_STATE, - &state->fpu, &scp->sc_i386_float_state, - sizeof (state->fpu)); + scp->xstate = NULL; +#ifdef i386_XFLOAT_STATE + if (xstate_size > 0) + { + mach_msg_type_number_t got = (xstate_size / sizeof (int)); + + ok = (! __thread_get_state (ss->thread, i386_XFLOAT_STATE, + (thread_state_t) stackframe->xstate, &got) + && got == (xstate_size / sizeof (int))); + + if (ok && ((struct i386_xfloat_state*) stackframe->xstate)->fp_save_kind > 5) + /* We support up to XSAVES */ + ok = 0; + + if (ok) + { + scp->xstate = (struct i386_xfloat_state*) stackframe->xstate; + assert((uintptr_t)scp->xstate->hw_state % 64 == 0); + } + } + else +#endif + ok = 0; + if (!ok) + { + /* struct sigcontext is laid out so that starting at sc_fpkind mimics + a struct i386_float_state. */ + _Static_assert (offsetof (struct sigcontext, sc_i386_float_state) + % __alignof__ (struct i386_float_state) == 0, + "sc_i386_float_state layout mismatch"); + ok = machine_get_state (ss->thread, state, i386_FLOAT_STATE, + &state->fpu, &scp->sc_i386_float_state, + sizeof (state->fpu)); + } /* Set up the arguments for the signal handler. */ stackframe->signo = signo; @@ -404,7 +461,10 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action - in gdb: gdb/i386-gnu-tdep.c gnu_sigtramp_code. */ #ifdef __x86_64__ -asm ("rpc_wait_trampoline:\n" +asm ("trampoline:\n" + "fnclex\n" /* Clear any pending exception. */ + "jmp _trampoline\n" + "rpc_wait_trampoline:\n" /* This is the entry point when we have an RPC reply message to receive before running the handler. The MACH_MSG_SEND bit has already been cleared in the OPTION argument in our %rsi. The interrupted user @@ -423,7 +483,7 @@ asm ("rpc_wait_trampoline:\n" /* Switch to the signal stack. */ "movq %rbx, %rsp\n" - "trampoline:\n" + "_trampoline:\n" /* Entry point for running the handler normally. The arguments to the handler function are on the top of the stack, same as in the i386 version: @@ -449,7 +509,10 @@ asm ("rpc_wait_trampoline:\n" "movq 16(%rsp), %rdi\n" "ret"); #else -asm ("rpc_wait_trampoline:\n"); +asm ("trampoline:\n" + "fnclex\n" /* Clear any pending exception. */ + "jmp _trampoline\n" + "rpc_wait_trampoline:\n"); /* This is the entry point when we have an RPC reply message to receive before running the handler. The MACH_MSG_SEND bit has already been cleared in the OPTION argument on our stack. The interrupted user @@ -469,7 +532,7 @@ asm (/* Retry the interrupted mach_msg system call. */ /* Switch to the signal stack. */ "movl %ebx, %esp\n"); - asm ("trampoline:\n"); +asm ("_trampoline:\n"); /* Entry point for running the handler normally. The arguments to the handler function are already on the top of the stack: |