diff options
| -rw-r--r-- | usr/src/lib/brand/lx/lx_brand/amd64/lx_handler.s | 20 | ||||
| -rw-r--r-- | usr/src/lib/brand/lx/lx_brand/common/lx_brand.c | 19 | ||||
| -rw-r--r-- | usr/src/lib/brand/lx/lx_brand/common/signal.c | 54 | ||||
| -rw-r--r-- | usr/src/lib/brand/lx/lx_brand/i386/lx_handler.s | 1 |
4 files changed, 60 insertions, 34 deletions
diff --git a/usr/src/lib/brand/lx/lx_brand/amd64/lx_handler.s b/usr/src/lib/brand/lx/lx_brand/amd64/lx_handler.s index f449f47be3..7cf509da13 100644 --- a/usr/src/lib/brand/lx/lx_brand/amd64/lx_handler.s +++ b/usr/src/lib/brand/lx/lx_brand/amd64/lx_handler.s @@ -285,6 +285,8 @@ lx_sigreturn_tolibc(uintptr_t sp) * | | stuff we saved in our prologue | * | ================================================= * | | LX_SIGRT_MAGIC | + * | ================================================= + * | | {unused word to maintain ABI stack alignment} | * V ================================================= * | Linux local data built by lx stk_builder() | * ================================================= @@ -297,7 +299,7 @@ lx_sigreturn_tolibc(uintptr_t sp) ENTRY_NP(lx_sigdeliver) pushq %rbp movq %rsp, %rbp - subq $0x30, %rsp + subq $0x40, %rsp /* an extra word to maintain alignmnt */ movq %rdi, -8(%rbp) /* sig */ movq %rsi, -16(%rbp) /* siginfo* */ movq %rdx, -24(%rbp) /* ucontext* */ @@ -305,16 +307,12 @@ lx_sigreturn_tolibc(uintptr_t sp) movq %r8, -40(%rbp) /* stack builder */ movq %r9, -48(%rbp) /* Linux signal handler */ - /* - * create stack_size stack buffer as a - * local varible - */ - subq %rcx, %rsp + subq %rcx, %rsp /* create stack_size stack buffer */ - movq $LX_SIGRT_MAGIC, %rcx /* load and "push" marker value onto */ - movq %rcx, -56(%rbp) /* stack for lx_rt_sigreturn */ + movq $LX_SIGRT_MAGIC, %rcx /* load and place marker value onto */ + movq %rcx, -56(%rbp) /* stack for lx_rt_sigreturn */ - movq %rsp, %rcx /* arg3 - %rcx stack pointer */ + movq %rsp, %rcx /* arg3 - %rcx is stack pointer */ /* arg2 - %rdx is ucontext ptr */ /* arg1 - %rsi is siginfo ptr */ /* arg0 - %rdi is sig num */ @@ -371,10 +369,6 @@ lx_sigreturn_tolibc(uintptr_t sp) * Trampoline code is called by the return at the end of a Linux * signal handler to return control to the interrupted application * via the lx_rt_sigreturn() syscall. - * - * This routine must consist of the EXACT code sequence below - * as gdb looks at the sequence of instructions a routine will return - * to determine whether it is in a signal handler or not. */ ENTRY_NP(lx_rt_sigreturn_tramp) movq $LX_SYS_rt_sigreturn, %rax diff --git a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c index 180e040a98..2f787a2368 100644 --- a/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c +++ b/usr/src/lib/brand/lx/lx_brand/common/lx_brand.c @@ -448,6 +448,16 @@ static int lx_emulate_args(lx_regs_t *rp, struct lx_sysent *s, uintptr_t *args) { #if defined(_LP64) + /* + * Note: Syscall argument passing is different from function call + * argument passing on amd64. For function calls, the fourth arg is + * passed via %rcx, but for system calls the 4th arg is passed via %r10. + * This is because in amd64, the syscall instruction puts the lower + * 32 bits of %rflags in %r11 and puts the %rip value to %rcx. + * + * Appendix A of the amd64 ABI (Linux conventions) states that syscalls + * are limited to 6 args and no arg is passed on the stack. + */ args[0] = rp->lxr_rdi; args[1] = rp->lxr_rsi; args[2] = rp->lxr_rdx; @@ -981,7 +991,16 @@ lx_syscall_regs(void) assert(fr->fr_savpc != NULL); } +#if defined(_LP64) + /* + * This is %rbp, update to be at the end of the frame for correct + * struct offsets. lx_emulate only takes one parameter, a pointer to + * lx_regs_t. + */ + return ((lx_regs_t *)(fr->fr_savfp - sizeof (lx_regs_t))); +#else return ((lx_regs_t *)((uintptr_t *)fr)[2]); +#endif } int diff --git a/usr/src/lib/brand/lx/lx_brand/common/signal.c b/usr/src/lib/brand/lx/lx_brand/common/signal.c index 73689bd163..042b9e0227 100644 --- a/usr/src/lib/brand/lx/lx_brand/common/signal.c +++ b/usr/src/lib/brand/lx/lx_brand/common/signal.c @@ -302,7 +302,7 @@ struct lx_sigstack { lx_siginfo_t si; /* saved signal information */ lx_ucontext_t uc; /* saved user context */ lx_fpstate_t fpstate; /* saved FP state */ - char trampoline[10]; /* code for trampoline to lx_rt_sigreturn() */ + char pad[2]; /* stack alignment */ }; #else struct lx_sigstack { @@ -779,6 +779,7 @@ lx_sigprocmask_common(uintptr_t how, uintptr_t l_setp, uintptr_t l_osetp, s_setp = &set; + /* Only 32-bit code passes other than USE_SIGSET */ if (sigset_type == USE_SIGSET) err = ltos_sigset((lx_sigset_t *)l_setp, s_setp); #if defined(_ILP32) @@ -1067,7 +1068,12 @@ lx_rt_sigreturn(void) */ sp = (uintptr_t)rp->lxr_esp - 4; #else - sp = (uintptr_t)rp->lxr_rsp; + /* + * We need to make an adjustment for 64-bit code as well. Since 64-bit + * does not use the trampoline, it's probably for the same reason as + * alluded to above. + */ + sp = (uintptr_t)rp->lxr_rsp - 8; #endif /* @@ -1090,6 +1096,9 @@ lx_rt_sigreturn(void) * Check for and remove LX_SIGRT_MAGIC from the stack. */ #if defined(_LP64) + /* account for extra word used in lx_sigdeliver for stack alignment */ + sp += 8; + if (*(uint64_t *)sp != LX_SIGRT_MAGIC) lx_err_fatal("sp @ 0x%p, expected 0x%x, found 0x%x!", sp, LX_SIGRT_MAGIC, *(uint32_t *)sp); @@ -1228,6 +1237,16 @@ lx_rt_sigreturn(void) static int lx_setcontext(const ucontext_t *ucp) { + extern int lx_traceflag; + + /* + * See we don't return via lx_emulate, issue a trace msg here if + * necessary. We know this is only called in the 64-bit rt_sigreturn + * code path to the syscall number is 15. + */ + if (lx_traceflag != 0) { + (void) syscall(SYS_brand, B_SYSRETURN, 15, 0); + } return (syscall(SYS_brand, B_SIGNAL_RETURN, ucp)); } #endif @@ -1334,17 +1353,16 @@ lx_build_signal_frame(int lx_sig, siginfo_t *sip, void *p, void *sp) if (lxsap && (lxsap->lxsa_flags & LX_SA_RESTORER) && lxsap->lxsa_restorer) { -#if defined(_LP64) /* - * lxsa_restorer is only set by sigaction in 32-bit code - * XXX should lxsa_restorer ever be set for 64-bit code? + * lxsa_restorer is explicitly set by sigaction in 32-bit code + * but it can also be implicitly set for both 32 and 64 bit + * code via lx_sigaction_common when we bcopy the user-supplied + * lx_sigaction element into the proper slot in the sighandler + * array. */ - assert(0); -#endif lx_ssp->retaddr = lxsap->lxsa_restorer; lx_debug("lxsa_restorer exists @ 0x%p", lx_ssp->retaddr); } else { - /* We should always take this path in 64-bit code */ lx_ssp->retaddr = lx_rt_sigreturn_tramp; lx_debug("lx_ssp->retaddr set to 0x%p", lx_rt_sigreturn_tramp); } @@ -1434,6 +1452,7 @@ lx_build_signal_frame(int lx_sig, siginfo_t *sip, void *p, void *sp) lx_ucp->uc_sigcontext.sc_fpstate = NULL; } +#if defined(_ILP32) /* * Believe it or not, gdb wants to SEE the sigreturn code on the * top of the stack to determine whether the stack frame belongs to @@ -1443,6 +1462,7 @@ lx_build_signal_frame(int lx_sig, siginfo_t *sip, void *p, void *sp) */ bcopy((void *)lx_rt_sigreturn_tramp, lx_ssp->trampoline, sizeof (lx_ssp->trampoline)); +#endif #if defined(_LP64) /* @@ -1465,7 +1485,6 @@ lx_call_user_handler(int sig, siginfo_t *sip, void *p) { void (*user_handler)(); void (*stk_builder)(); - #if defined(_ILP32) lx_tsd_t *lx_tsd; int err; @@ -1503,6 +1522,10 @@ lx_call_user_handler(int sig, siginfo_t *sip, void *p) #if defined(_LP64) /* %gs is ignored in the 64-bit lx_sigdeliver */ gs = 0; + + stksize = sizeof (struct lx_sigstack); + stk_builder = lx_build_signal_frame; + #else if ((err = thr_getspecific(lx_tsd_key, (void **)&lx_tsd)) != 0) lx_err_fatal("lx_call_user_handler: unable to read " @@ -1518,21 +1541,15 @@ lx_call_user_handler(int sig, siginfo_t *sip, void *p) * bugs in the library. This is only applicable to 32-bit code. */ assert(gs != 0); -#endif if (lxsap->lxsa_flags & LX_SA_SIGINFO) { stksize = sizeof (struct lx_sigstack); stk_builder = lx_build_signal_frame; } else { -#if defined(_LP64) - /* 64-bit code should never generate old-style signals */ - stk_builder = NULL; /* shutup the compiler */ - assert(0); -#else stksize = sizeof (struct lx_oldsigstack); stk_builder = lx_build_old_signal_frame; -#endif } +#endif user_handler = lxsap->lxsa_handler; @@ -1787,11 +1804,6 @@ lx_rt_sigaction(uintptr_t lx_sig, uintptr_t actp, uintptr_t oactp, if ((size_t)setsize != sizeof (lx_sigset_t)) return (-EINVAL); - /* - * XXX - for 64 bit code this is the only sigaction. Why don't we have - * the logic around lx_sigaction in this code path? - */ - return (lx_sigaction_common(lx_sig, (struct lx_sigaction *)actp, (struct lx_sigaction *)oactp)); } diff --git a/usr/src/lib/brand/lx/lx_brand/i386/lx_handler.s b/usr/src/lib/brand/lx/lx_brand/i386/lx_handler.s index e8e944fd03..b6cdf3f4fe 100644 --- a/usr/src/lib/brand/lx/lx_brand/i386/lx_handler.s +++ b/usr/src/lib/brand/lx/lx_brand/i386/lx_handler.s @@ -360,6 +360,7 @@ lx_sigreturn_tolibc(uintptr_t sp) * These two routines must consist of the EXACT code sequences below * as gdb looks at the sequence of instructions a routine will return * to determine whether it is in a signal handler or not. + * See the Linux code setup_signal_stack_sc() in arch/x86/um/signal.c. */ ENTRY_NP(lx_sigreturn_tramp) popl %eax |