Mercurial > gnulib
changeset 40041:4584f15ba9c0
c-stack: Fix for Linux/sparc.
* m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Set
ac_cv_sys_xsi_stack_overflow_heuristic to 'no' on Linux/sparc.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Sun, 16 Dec 2018 23:18:36 +0100 |
| parents | 9050cdbaac75 |
| children | bd426cb23907 |
| files | ChangeLog m4/c-stack.m4 |
| diffstat | 2 files changed, 134 insertions(+), 115 deletions(-) [+] |
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--- a/ChangeLog Sun Dec 16 21:31:15 2018 +0100 +++ b/ChangeLog Sun Dec 16 23:18:36 2018 +0100 @@ -1,3 +1,9 @@ +2018-12-16 Bruno Haible <bruno@clisp.org> + + c-stack: Fix for Linux/sparc. + * m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Set + ac_cv_sys_xsi_stack_overflow_heuristic to 'no' on Linux/sparc. + 2018-12-16 Bruno Haible <bruno@clisp.org> localename: Avoid test failure on some glibc systems.
--- a/m4/c-stack.m4 Sun Dec 16 21:31:15 2018 +0100 +++ b/m4/c-stack.m4 Sun Dec 16 23:18:36 2018 +0100 @@ -7,7 +7,7 @@ # Written by Paul Eggert. -# serial 16 +# serial 17 AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC], [ @@ -201,127 +201,140 @@ AC_CACHE_CHECK([for precise C stack overflow detection], [ac_cv_sys_xsi_stack_overflow_heuristic], - [AC_RUN_IFELSE([AC_LANG_SOURCE( - [[ - #include <unistd.h> - #include <signal.h> - #if HAVE_UCONTEXT_H - # include <ucontext.h> - #endif - #if HAVE_SETRLIMIT - # include <sys/types.h> - # include <sys/time.h> - # include <sys/resource.h> - #endif - #ifndef SIGSTKSZ - # define SIGSTKSZ 16384 - #endif - - static union - { - char buffer[2 * SIGSTKSZ]; - long double ld; - long u; - void *p; - } alternate_signal_stack; + [dnl On Linux/sparc64 (both in 32-bit and 64-bit mode), it would be wrong + dnl to set HAVE_XSI_STACK_OVERFLOW_HEURISTIC to 1, because the third + dnl argument passed to the segv_handler is a 'struct sigcontext *', not + dnl an 'ucontext_t *'. It would lead to a failure of test-c-stack2.sh. + case "${host_os}--${host_cpu}" in + linux*--sparc*) + ac_cv_sys_xsi_stack_overflow_heuristic=no + ;; + *) + AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[ + #include <unistd.h> + #include <signal.h> + #if HAVE_UCONTEXT_H + # include <ucontext.h> + #endif + #if HAVE_SETRLIMIT + # include <sys/types.h> + # include <sys/time.h> + # include <sys/resource.h> + #endif + #ifndef SIGSTKSZ + # define SIGSTKSZ 16384 + #endif - #if STACK_DIRECTION - # define find_stack_direction(ptr) STACK_DIRECTION - #else - static int - find_stack_direction (char const *addr) - { - char dummy; - return (! addr ? find_stack_direction (&dummy) - : addr < &dummy ? 1 : -1); - } - #endif - - static void - segv_handler (int signo, siginfo_t *info, void *context) - { - if (0 < info->si_code) + static union { - /* For XSI heuristics to work, we need uc_stack to describe - the interrupted stack (as on Solaris), and not the - currently executing stack (as on Linux). */ - ucontext_t const *user_context = context; - char const *stack_min = user_context->uc_stack.ss_sp; - size_t stack_size = user_context->uc_stack.ss_size; - char const *faulting_address = info->si_addr; - size_t s = faulting_address - stack_min; - size_t page_size = sysconf (_SC_PAGESIZE); - if (find_stack_direction (0) < 0) - s += page_size; - if (s < stack_size + page_size) - _exit (0); - _exit (4); + char buffer[2 * SIGSTKSZ]; + long double ld; + long u; + void *p; + } alternate_signal_stack; + + #if STACK_DIRECTION + # define find_stack_direction(ptr) STACK_DIRECTION + #else + static int + find_stack_direction (char const *addr) + { + char dummy; + return (! addr ? find_stack_direction (&dummy) + : addr < &dummy ? 1 : -1); } - _exit (5); - } + #endif - static int - c_stack_action () - { - stack_t st; - struct sigaction act; - int r; + static void + segv_handler (int signo, siginfo_t *info, void *context) + { + if (0 < info->si_code) + { + /* For XSI heuristics to work, we need uc_stack to + describe the interrupted stack (as on Solaris), and + not the currently executing stack (as on Linux). */ + ucontext_t const *user_context = context; + char const *stack_min = user_context->uc_stack.ss_sp; + size_t stack_size = user_context->uc_stack.ss_size; + char const *faulting_address = info->si_addr; + size_t s = faulting_address - stack_min; + size_t page_size = sysconf (_SC_PAGESIZE); + if (find_stack_direction (0) < 0) + s += page_size; + if (s < stack_size + page_size) + _exit (0); + _exit (4); + } + _exit (5); + } - st.ss_flags = 0; - /* Use the midpoint to avoid Irix sigaltstack bug. */ - st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ; - st.ss_size = SIGSTKSZ; - r = sigaltstack (&st, 0); - if (r != 0) - return 1; + static int + c_stack_action () + { + stack_t st; + struct sigaction act; + int r; + + st.ss_flags = 0; + /* Use the midpoint to avoid Irix sigaltstack bug. */ + st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ; + st.ss_size = SIGSTKSZ; + r = sigaltstack (&st, 0); + if (r != 0) + return 1; - sigemptyset (&act.sa_mask); - act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO; - act.sa_sigaction = segv_handler; - #if FAULT_YIELDS_SIGBUS - if (sigaction (SIGBUS, &act, 0) < 0) - return 2; - #endif - if (sigaction (SIGSEGV, &act, 0) < 0) - return 3; - return 0; - } - static volatile int * - recurse_1 (volatile int n, volatile int *p) - { - if (n >= 0) - *recurse_1 (n + 1, p) += n; - return p; - } - static int - recurse (volatile int n) - { - int sum = 0; - return *recurse_1 (n, &sum); - } - int - main () - { - int result; - #if HAVE_SETRLIMIT && defined RLIMIT_STACK - /* Before starting the endless recursion, try to be friendly - to the user's machine. On some Linux 2.2.x systems, there - is no stack limit for user processes at all. We don't want - to kill such systems. */ - struct rlimit rl; - rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */ - setrlimit (RLIMIT_STACK, &rl); - #endif + sigemptyset (&act.sa_mask); + act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO; + act.sa_sigaction = segv_handler; + #if FAULT_YIELDS_SIGBUS + if (sigaction (SIGBUS, &act, 0) < 0) + return 2; + #endif + if (sigaction (SIGSEGV, &act, 0) < 0) + return 3; + return 0; + } + static volatile int * + recurse_1 (volatile int n, volatile int *p) + { + if (n >= 0) + *recurse_1 (n + 1, p) += n; + return p; + } + static int + recurse (volatile int n) + { + int sum = 0; + return *recurse_1 (n, &sum); + } + int + main () + { + int result; + #if HAVE_SETRLIMIT && defined RLIMIT_STACK + /* Before starting the endless recursion, try to be friendly + to the user's machine. On some Linux 2.2.x systems, there + is no stack limit for user processes at all. We don't want + to kill such systems. */ + struct rlimit rl; + rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */ + setrlimit (RLIMIT_STACK, &rl); + #endif - result = c_stack_action (); - if (result != 0) - return result; - return recurse (0); - } - ]])], - [ac_cv_sys_xsi_stack_overflow_heuristic=yes], - [ac_cv_sys_xsi_stack_overflow_heuristic=no], - [ac_cv_sys_xsi_stack_overflow_heuristic=cross-compiling])]) + result = c_stack_action (); + if (result != 0) + return result; + return recurse (0); + } + ]])], + [ac_cv_sys_xsi_stack_overflow_heuristic=yes], + [ac_cv_sys_xsi_stack_overflow_heuristic=no], + [ac_cv_sys_xsi_stack_overflow_heuristic=cross-compiling]) + ;; + esac + ]) if test $ac_cv_sys_xsi_stack_overflow_heuristic = yes; then AC_DEFINE([HAVE_XSI_STACK_OVERFLOW_HEURISTIC], [1],