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author | Richard Henderson <rth@redhat.com> | 2014-05-23 15:44:23 -0400 |
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committer | Richard Henderson <rth@redhat.com> | 2014-06-03 11:04:04 -0400 |
commit | 111cc714894d71fdc31c04e56b1bcd41b2680269 (patch) | |
tree | 5d69bd81441b97d5880c0e27c194dc1de7f37b01 /sysdeps/unix/sysv/linux/aarch64/clone.S | |
parent | ccc39911132db27b385b4dd196cf2bb82f2d03c2 (diff) | |
download | glibc-111cc714894d71fdc31c04e56b1bcd41b2680269.tar.gz glibc-111cc714894d71fdc31c04e56b1bcd41b2680269.tar.xz glibc-111cc714894d71fdc31c04e56b1bcd41b2680269.zip |
aarch64: Consolidate NPTL/non versions of clone
At the same time, rely on non-clobbered registers across syscall so that we eliminate the stack frame that we previously ignored in the unwind info.
Diffstat (limited to 'sysdeps/unix/sysv/linux/aarch64/clone.S')
-rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/clone.S | 56 |
1 files changed, 24 insertions, 32 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S index f2964f4871..a2b5a2bc24 100644 --- a/sysdeps/unix/sysv/linux/aarch64/clone.S +++ b/sysdeps/unix/sysv/linux/aarch64/clone.S @@ -39,47 +39,42 @@ */ .text ENTRY(__clone) + /* Save args for the child. */ + mov x10, x0 + mov x11, x2 + mov x12, x3 + /* Sanity check args. */ - cbz x0, 1f - cbz x1, 1f - /* Insert the args onto the new stack. */ - stp x0, x3, [x1, #-16]! /* Fn, arg. */ + mov x0, #-EINVAL + cbz x10, .Lsyscall_error + cbz x1, .Lsyscall_error /* Do the system call. */ + /* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid. */ mov x0, x2 /* flags */ - /* New sp is already in x1. */ mov x2, x4 /* ptid */ mov x3, x5 /* tls */ mov x4, x6 /* ctid */ - -#ifdef RESET_PID - /* We rely on the kernel preserving the argument regsiters across a - each system call so that we can inspect the flags against after - the clone call. */ - mov x5, x0 -#endif - mov x8, #SYS_ify(clone) - /* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid. */ svc 0x0 - cfi_endproc + cmp x0, #0 - beq 2f - blt 3f + beq thread_start + blt .Lsyscall_error RET -1: mov x0, #-EINVAL -3: - b syscall_error +PSEUDO_END (__clone) -2: + .align 4 + .type thread_start, %function +thread_start: cfi_startproc cfi_undefined (x30) mov x29, 0 -#ifdef RESET_PID - tbnz x5, #CLONE_THREAD_BIT, 3f + + tbnz x11, #CLONE_THREAD_BIT, 3f mov x0, #-1 - tbnz x5, #CLONE_VM_BIT, 2f + tbnz x11, #CLONE_VM_BIT, 2f mov x8, #SYS_ify(getpid) svc 0x0 2: @@ -87,18 +82,15 @@ ENTRY(__clone) sub x1, x1, #PTHREAD_SIZEOF str w0, [x1, #PTHREAD_PID_OFFSET] str w0, [x1, #PTHREAD_TID_OFFSET] - 3: -#endif - /* Pick the function arg and call address from the stack and - execute. */ - ldp x1, x0, [sp], #16 - blr x1 + + /* Pick the function arg and execute. */ + mov x0, x12 + blr x10 /* We are done, pass the return value through x0. */ b HIDDEN_JUMPTARGET(_exit) cfi_endproc - cfi_startproc -PSEUDO_END (__clone) + .size thread_start, .-thread_start weak_alias (__clone, clone) |