From 478593e6374f3818da39332260dc453cb19cfa1e Mon Sep 17 00:00:00 2001 From: Stefan Liebler Date: Mon, 4 Dec 2017 16:40:13 +0100 Subject: S390: Fix backtrace in vdso functions. On s390, GDB fails to show the complete backtrace from within vdso functions. The macro INTERNAL_VSYSCALL_CALL saves the return address in r14 to r10 before branching to the vdso function. The branch-instruction updates r14 in order to let the vdso function return. Then the original address in r14 is restored from r10. Unfortunately, there are no cfi-rules and GDB fails. Furthermore the call of the vdso function does not comply with the s390 ABI as no stack-frame for the vdso-function is generated. This patch removes the s390 specific macro INTERNAL_VSYSCALL_CALL and the common implementation in sysdeps/unix/sysv/linux/sysdep-vdso.h is used. Then the vdso function is called via function-pointer and GCC generates a new stack-frame and emits all needed cfi-rules. The defines CLOBBER_[0-6] are removed as they were only used in macro INTERNAL_VSYSCALL_CALL. The macro INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK is not used on s390. The only user is power. Thus it is removed from s390 sysdep.h. ChangeLog: * sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h (INTERNAL_VSYSCALL_CALL, CLOBBER_0, CLOBBER_1, CLOBBER_2, CLOBBER_3, CLOBBER_4, CLOBBER_5, CLOBBER_6, INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK): Remove. * sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h: Likewise. --- sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h | 36 --------------------------- 1 file changed, 36 deletions(-) (limited to 'sysdeps/unix/sysv/linux/s390/s390-64') diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h index 622991d84d..18ed3398aa 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h +++ b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h @@ -277,14 +277,6 @@ #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6) #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7) -#define CLOBBER_0 , "3", "4", "5" -#define CLOBBER_1 , "3", "4", "5" -#define CLOBBER_2 , "4", "5" -#define CLOBBER_3 , "5" -#define CLOBBER_4 -#define CLOBBER_5 -#define CLOBBER_6 - /* List of system calls which are supported as vsyscalls. */ #define HAVE_CLOCK_GETRES_VSYSCALL 1 #define HAVE_CLOCK_GETTIME_VSYSCALL 1 @@ -293,34 +285,6 @@ #define SINGLE_THREAD_BY_GLOBAL 1 -/* This version is for internal uses when there is no desire - to set errno */ -#define INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK(name, err, nr, args...) \ - ({ \ - long int _ret = ENOSYS; \ - \ - __typeof (__vdso_##name) vdsop = __vdso_##name; \ - PTR_DEMANGLE (vdsop); \ - if (vdsop != NULL) \ - _ret = INTERNAL_VSYSCALL_CALL (vdsop, err, nr, ##args); \ - else \ - err = 1 << 28; \ - _ret; \ - }) - -#define INTERNAL_VSYSCALL_CALL(fn, err, nr, args...) \ - ({ \ - DECLARGS_##nr(args) \ - register long _ret __asm__("2"); \ - __asm__ __volatile__ ( \ - "lgr 10,14\n\t" \ - "basr 14,%1\n\t" \ - "lgr 14,10\n\t" \ - : "=d" (_ret) \ - : "a" (fn) ASMFMT_##nr \ - : "cc", "memory", "0", "1", "10" CLOBBER_##nr); \ - _ret; }) - /* Pointer mangling support. */ #if IS_IN (rtld) /* We cannot use the thread descriptor because in ld.so we use setjmp -- cgit 1.4.1