From 738860089d5c510f3445f9830d9924ab58659c51 Mon Sep 17 00:00:00 2001 From: Ulrich Weigand Date: Mon, 21 Mar 2011 20:44:01 +0000 Subject: [PATCH] Create ARM unwind records for system call stubs. --- ChangeLog.arm | 27 +++++ .../sysv/linux/arm/eabi/nptl/sysdep-cancel.h | 103 +++++++++--------- sysdeps/unix/sysv/linux/arm/eabi/sysdep.h | 91 +++++++++++++++- sysdeps/unix/sysv/linux/arm/vfork.S | 23 +++- 4 files changed, 186 insertions(+), 58 deletions(-) diff --git a/ChangeLog.arm b/ChangeLog.arm index 346440446a..3f4ae8c5c0 100644 --- a/ChangeLog.arm +++ b/ChangeLog.arm @@ -1,3 +1,30 @@ +2011-03-21 Ulrich Weigand + + * sysdeps/unix/sysv/arm/eabi/sysdep.h (DO_CALL): Do not save/restore + r7 into IP. + (DOARGS_0, UNDOARGS_0): Redefine to save/restore r7 to the stack. + Create appropriate ARM unwind record. + (DOARGS_1, UNDOARGS_1): Likewise. + (DOARGS_2, UNDOARGS_2): Likewise. + (DOARGS_3, UNDOARGS_3): Likewise. + (DOARGS_4, UNDOARGS_4): Likewise. + (DOARGS_5, UNDOARGS_5): Likewise. + (DOARGS_6, UNDOARGS_6): Likewise. + (DOARGS_7, UNDOARGS_7): Likewise. + * sysdeps/unix/sysv/arm/eabi/nptl/sysdep-cancel.h (PSEUDO): Adapt to + DO_CALL/DOARGS_xxx/UNDOARGS_xxx changes. + (RESTART_UNWIND): Likewise. + (DOCARGS_0, RESTORE_LR_0): Likewise. + (DOCARGS_1): Likewise. + (DOCARGS_2): Likewise. + (DOCARGS_3): Likewise. + (DOCARGS_4): Likewise. + (DOCARGS_5, UNDOCARGS_5, RESTORE_LR_5): Likewise. + (DOCARGS_6, UNDOCARGS_6): Likewise. + * sysdeps/unix/sysv/linux/arm/vfork.S (__vfork): Do no use DO_CALL to + call vfork. In the __ARM_EABI__ case, save r7 both to IP (to restore + from) and the stack (to create an ARM unwind record). + 2011-03-21 Joseph Myers * sysdeps/arm/eabi/__longjmp.S, sysdeps/arm/eabi/bits/fenv.h, diff --git a/sysdeps/unix/sysv/linux/arm/eabi/nptl/sysdep-cancel.h b/sysdeps/unix/sysv/linux/arm/eabi/nptl/sysdep-cancel.h index 458558b9cf..f4a8af403a 100644 --- a/sysdeps/unix/sysv/linux/arm/eabi/nptl/sysdep-cancel.h +++ b/sysdeps/unix/sysv/linux/arm/eabi/nptl/sysdep-cancel.h @@ -47,20 +47,20 @@ DOARGS_##args; \ bne .Lpseudo_cancel; \ cfi_remember_state; \ - DO_CALL (syscall_name, 0); \ + ldr r7, =SYS_ify (syscall_name); \ + swi 0x0; \ UNDOARGS_##args; \ cmn r0, $4096; \ PSEUDO_RET; \ cfi_restore_state; \ .Lpseudo_cancel: \ - .fnstart; \ + .fnstart; /* matched by the .fnend in UNDOARGS below. */ \ DOCARGS_##args; /* save syscall args etc. around CENABLE. */ \ CENABLE; \ mov ip, r0; /* put mask in safe place. */ \ UNDOCARGS_##args; /* restore syscall args. */ \ ldr r7, =SYS_ify (syscall_name); \ swi 0x0; /* do the call. */ \ - .fnend; /* Past here we can't easily unwind. */ \ mov r7, r0; /* save syscall return value. */ \ mov r0, ip; /* get mask back. */ \ CDISABLE; \ @@ -69,34 +69,34 @@ UNDOARGS_##args; \ cmn r0, $4096 -/* DOARGS pushes four bytes on the stack for five arguments, eight bytes for - six arguments, and nothing for fewer. In order to preserve doubleword +/* DOARGS pushes eight bytes on the stack for five arguments, twelve bytes for + six arguments, and four bytes for fewer. In order to preserve doubleword alignment, sometimes we must save an extra register. */ # define RESTART_UNWIND \ .fnend; \ .fnstart; \ - .save {r7, lr} + .save {r7}; \ + .save {lr} # define DOCARGS_0 \ - stmfd sp!, {r7, lr}; \ - cfi_adjust_cfa_offset (8); \ - cfi_rel_offset (r7, 0); \ - cfi_rel_offset (lr, 4); \ - .save {r7, lr} + .save {r7}; \ + str lr, [sp, #-4]!; \ + cfi_adjust_cfa_offset (4); \ + cfi_rel_offset (lr, 0); \ + .save {lr} # define UNDOCARGS_0 # define RESTORE_LR_0 \ - ldmfd sp!, {r7, lr}; \ - cfi_adjust_cfa_offset (-8); \ - cfi_restore (r7); \ + ldr lr, [sp], #4; \ + cfi_adjust_cfa_offset (-4); \ cfi_restore (lr) # define DOCARGS_1 \ - stmfd sp!, {r0, r1, r7, lr}; \ - cfi_adjust_cfa_offset (16); \ - cfi_rel_offset (r7, 8); \ - cfi_rel_offset (lr, 12); \ - .save {r7, lr}; \ + .save {r7}; \ + stmfd sp!, {r0, r1, lr}; \ + cfi_adjust_cfa_offset (12); \ + cfi_rel_offset (lr, 8); \ + .save {lr}; \ .pad #8 # define UNDOCARGS_1 \ ldr r0, [sp], #8; \ @@ -106,11 +106,11 @@ RESTORE_LR_0 # define DOCARGS_2 \ - stmfd sp!, {r0, r1, r7, lr}; \ - cfi_adjust_cfa_offset (16); \ - cfi_rel_offset (r7, 8); \ - cfi_rel_offset (lr, 12); \ - .save {r7, lr}; \ + .save {r7}; \ + stmfd sp!, {r0, r1, lr}; \ + cfi_adjust_cfa_offset (12); \ + cfi_rel_offset (lr, 8); \ + .save {lr}; \ .pad #8 # define UNDOCARGS_2 \ ldmfd sp!, {r0, r1}; \ @@ -120,11 +120,11 @@ RESTORE_LR_0 # define DOCARGS_3 \ - stmfd sp!, {r0, r1, r2, r3, r7, lr}; \ - cfi_adjust_cfa_offset (24); \ - cfi_rel_offset (r7, 16); \ - cfi_rel_offset (lr, 20); \ - .save {r7, lr}; \ + .save {r7}; \ + stmfd sp!, {r0, r1, r2, r3, lr}; \ + cfi_adjust_cfa_offset (20); \ + cfi_rel_offset (lr, 16); \ + .save {lr}; \ .pad #16 # define UNDOCARGS_3 \ ldmfd sp!, {r0, r1, r2, r3}; \ @@ -134,11 +134,11 @@ RESTORE_LR_0 # define DOCARGS_4 \ - stmfd sp!, {r0, r1, r2, r3, r7, lr}; \ - cfi_adjust_cfa_offset (24); \ - cfi_rel_offset (r7, 16); \ - cfi_rel_offset (lr, 20); \ - .save {r7, lr}; \ + .save {r7}; \ + stmfd sp!, {r0, r1, r2, r3, lr}; \ + cfi_adjust_cfa_offset (20); \ + cfi_rel_offset (lr, 16); \ + .save {lr}; \ .pad #16 # define UNDOCARGS_4 \ ldmfd sp!, {r0, r1, r2, r3}; \ @@ -149,43 +149,40 @@ /* r4 is only stmfd'ed for correct stack alignment. */ # define DOCARGS_5 \ - .save {r4}; \ - stmfd sp!, {r0, r1, r2, r3, r4, r7, lr}; \ - cfi_adjust_cfa_offset (28); \ - cfi_rel_offset (r7, 20); \ - cfi_rel_offset (lr, 24); \ - .save {r7, lr}; \ + .save {r4, r7}; \ + stmfd sp!, {r0, r1, r2, r3, r4, lr}; \ + cfi_adjust_cfa_offset (24); \ + cfi_rel_offset (lr, 20); \ + .save {lr}; \ .pad #20 # define UNDOCARGS_5 \ ldmfd sp!, {r0, r1, r2, r3}; \ cfi_adjust_cfa_offset (-16); \ .fnend; \ .fnstart; \ - .save {r4}; \ - .save {r7, lr}; \ + .save {r4, r7}; \ + .save {lr}; \ .pad #4 # define RESTORE_LR_5 \ - ldmfd sp!, {r4, r7, lr}; \ - cfi_adjust_cfa_offset (-12); \ + ldmfd sp!, {r4, lr}; \ + cfi_adjust_cfa_offset (-8); \ /* r4 will be marked as restored later. */ \ - cfi_restore (r7); \ cfi_restore (lr) # define DOCARGS_6 \ - .save {r4, r5}; \ - stmfd sp!, {r0, r1, r2, r3, r7, lr}; \ - cfi_adjust_cfa_offset (24); \ - cfi_rel_offset (r7, 16); \ - cfi_rel_offset (lr, 20); \ - .save {r7, lr}; \ + .save {r4, r5, r7}; \ + stmfd sp!, {r0, r1, r2, r3, lr}; \ + cfi_adjust_cfa_offset (20); \ + cfi_rel_offset (lr, 16); \ + .save {lr}; \ .pad #16 # define UNDOCARGS_6 \ ldmfd sp!, {r0, r1, r2, r3}; \ cfi_adjust_cfa_offset (-16); \ .fnend; \ .fnstart; \ - .save {r4, r5}; \ - .save {r7, lr} + .save {r4, r5, r7}; \ + .save {lr}; # define RESTORE_LR_6 \ RESTORE_LR_0 diff --git a/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h b/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h index b7815babf4..a80621e142 100644 --- a/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h +++ b/sysdeps/unix/sysv/linux/arm/eabi/sysdep.h @@ -106,12 +106,95 @@ #undef DO_CALL #define DO_CALL(syscall_name, args) \ DOARGS_##args; \ - mov ip, r7; \ - cfi_register (r7, ip); \ ldr r7, =SYS_ify (syscall_name); \ swi 0x0; \ - mov r7, ip; \ - cfi_restore (r7); \ UNDOARGS_##args +#undef DOARGS_0 +#define DOARGS_0 \ + .fnstart; \ + str r7, [sp, #-4]!; \ + cfi_adjust_cfa_offset (4); \ + cfi_rel_offset (r7, 0); \ + .save { r7 } +#undef DOARGS_1 +#define DOARGS_1 DOARGS_0 +#undef DOARGS_2 +#define DOARGS_2 DOARGS_0 +#undef DOARGS_3 +#define DOARGS_3 DOARGS_0 +#undef DOARGS_4 +#define DOARGS_4 DOARGS_0 +#undef DOARGS_5 +#define DOARGS_5 \ + .fnstart; \ + stmfd sp!, {r4, r7}; \ + cfi_adjust_cfa_offset (8); \ + cfi_rel_offset (r4, 0); \ + cfi_rel_offset (r7, 4); \ + .save { r4, r7 }; \ + ldr r4, [sp, #8] +#undef DOARGS_6 +#define DOARGS_6 \ + .fnstart; \ + mov ip, sp; \ + stmfd sp!, {r4, r5, r7}; \ + cfi_adjust_cfa_offset (12); \ + cfi_rel_offset (r4, 0); \ + cfi_rel_offset (r5, 4); \ + cfi_rel_offset (r7, 8); \ + .save { r4, r5, r7 }; \ + ldmia ip, {r4, r5} +#undef DOARGS_7 +#define DOARGS_7 \ + .fnstart; \ + mov ip, sp; \ + stmfd sp!, {r4, r5, r6, r7}; \ + cfi_adjust_cfa_offset (16); \ + cfi_rel_offset (r4, 0); \ + cfi_rel_offset (r5, 4); \ + cfi_rel_offset (r6, 8); \ + cfi_rel_offset (r7, 12); \ + .save { r4, r5, r6, r7 }; \ + ldmia ip, {r4, r5, r6} + +#undef UNDOARGS_0 +#define UNDOARGS_0 \ + ldr r7, [sp], #4; \ + cfi_adjust_cfa_offset (-4); \ + cfi_restore (r7); \ + .fnend +#undef UNDOARGS_1 +#define UNDOARGS_1 UNDOARGS_0 +#undef UNDOARGS_2 +#define UNDOARGS_2 UNDOARGS_0 +#undef UNDOARGS_3 +#define UNDOARGS_3 UNDOARGS_0 +#undef UNDOARGS_4 +#define UNDOARGS_4 UNDOARGS_0 +#undef UNDOARGS_5 +#define UNDOARGS_5 \ + ldmfd sp!, {r4, r7}; \ + cfi_adjust_cfa_offset (-8); \ + cfi_restore (r4); \ + cfi_restore (r7); \ + .fnend +#undef UNDOARGS_6 +#define UNDOARGS_6 \ + ldmfd sp!, {r4, r5, r7}; \ + cfi_adjust_cfa_offset (-12); \ + cfi_restore (r4); \ + cfi_restore (r5); \ + cfi_restore (r7); \ + .fnend +#undef UNDOARGS_7 +#define UNDOARGS_7 \ + ldmfd sp!, {r4, r5, r6, r7}; \ + cfi_adjust_cfa_offset (-16); \ + cfi_restore (r4); \ + cfi_restore (r5); \ + cfi_restore (r6); \ + cfi_restore (r7); \ + .fnend + #endif /* _LINUX_ARM_EABI_SYSDEP_H */ diff --git a/sysdeps/unix/sysv/linux/arm/vfork.S b/sysdeps/unix/sysv/linux/arm/vfork.S index a020658989..e63690eecb 100644 --- a/sysdeps/unix/sysv/linux/arm/vfork.S +++ b/sysdeps/unix/sysv/linux/arm/vfork.S @@ -33,7 +33,28 @@ ENTRY (__vfork) #ifdef SAVE_PID SAVE_PID #endif - DO_CALL (vfork, 0) +#ifdef __ARM_EABI__ + /* The DO_CALL macro saves r7 on the stack, to enable generation + of ARM unwind info. Since the stack is initially shared between + parent and child of vfork, that saved value could be corrupted. + To avoid this problem, we save r7 into ip as well, and restore + from there. */ + mov ip, r7 + cfi_register (r7, ip) + .fnstart + str r7, [sp, #-4]! + cfi_adjust_cfa_offset (4) + .save { r7 } + ldr r7, =SYS_ify (vfork) + swi 0x0 + .fnend + add sp, sp, #4 + cfi_adjust_cfa_offset (-4) + mov r7, ip + cfi_restore (r7); +#else + swi SYS_ify(vfork) +#endif #ifdef RESTORE_PID RESTORE_PID #endif