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authorrofl0r <retnyg@gmx.net>2012-11-19 06:21:48 +0100
committerrofl0r <retnyg@gmx.net>2012-11-19 16:58:09 +0100
commit3fae236e00068d17e007275717940f5d5e94ba1a (patch)
treecd95a0eb060b4e31cf8993e4ffd08fe9597e9689 /src
parent6c0cba819fb593f1efa33e0acd0bf59597279d97 (diff)
downloadmusl-3fae236e00068d17e007275717940f5d5e94ba1a.tar.gz
powerpc: handle syscall error in clone.
sigsetjmp: store temporaries in jmp_buf rather than on stack.
Diffstat (limited to 'src')
-rw-r--r--src/signal/powerpc/sigsetjmp.s29
-rw-r--r--src/thread/powerpc/clone.s34
2 files changed, 24 insertions, 39 deletions
diff --git a/src/signal/powerpc/sigsetjmp.s b/src/signal/powerpc/sigsetjmp.s
index deed732f..a23463d2 100644
--- a/src/signal/powerpc/sigsetjmp.s
+++ b/src/signal/powerpc/sigsetjmp.s
@@ -10,25 +10,26 @@ sigsetjmp:
#2) if its 0, goto setjmp code
beq- cr7, 1f
#3) else: we must call pthread_sigmask(SIG_SETMASK, 0, (sigset_t *)buf->__ss);
- # increase stack frame by 16
- subi 1, 1, 16
- # thus store r3 on the stack, to restore it later
- stw 3, 12(1)
- # store old link reg
- mflr 0
- stw 0, 8(1)
+ # store non-volatile regs 30, 31 into the setjmp buf
+ stw 30, 0(3)
+ stw 31, 4(3)
+ # use them to store the pointer to the jmpbuf and the link reg
+ mr 30, 3
+ mflr 31
+
# put pointer to ss buf into r5 (3rd arg)
addi 5, 3, 260
# put "2" i.e. SIG_SETMASK in r3
li 3, 2
li 4, 0
bl pthread_sigmask
- #restore r3
- lwz 3, 12(1)
- #restore link reg
- lwz 0, 8(1)
- mtlr 0
- #restore sp
- addi 1, 1, 16
+
+ #restore jmpbuf pointer and link reg
+ mr 3, 30
+ mtlr 31
+ #resore non-volatile regs
+ lwz 30, 0(3)
+ lwz 31, 4(3)
+
1:
b setjmp
diff --git a/src/thread/powerpc/clone.s b/src/thread/powerpc/clone.s
index 54a2314e..dc5c74c6 100644
--- a/src/thread/powerpc/clone.s
+++ b/src/thread/powerpc/clone.s
@@ -13,12 +13,10 @@ __clone:
# SYS_clone = 120
# SYS_exit = 1
-# in order that the child can find the start func and its arg, we need to store it into
-# non-volative regs. to do so, we have to store those 2 regs into our stackframe, so
-# we can restore them later.
-subi 1, 1, 16
-stw 30, 12(1)
-stw 31, 8(1)
+# store non-volatile regs r30, r31 on stack in order to put our
+# start func and its arg there
+stwu 30, -16(1)
+stw 31, 4(1)
# save r3 (func) into r30, and r6(arg) into r31
mr 30, 3
@@ -37,19 +35,9 @@ li 0, 120
sc
# check for syscall error
-#this code should be more efficient, but it borks
-#bns+ 1f # jump to label 1 if no summary overflow.
+bns+ 1f # jump to label 1 if no summary overflow.
#else
-#neg 3, 3 #negate the result (errno)
-#b 2f # jump to epilogue
-
-# this error check code at least does not spoil the clone call.
-#mfcr 0 # Check for an error
-#rlwinm 4, 0, 0, 3, 3 # by checking for bit 28.
-#cmplwi 0, 4, 0 # It is an error if non-zero.
-#beq 0, 1f # Jump if not an error.
-#neg 3, 3 # Negate the error number.
-#b 2f # jump to epilogue
+neg 3, 3 #negate the result (errno)
1:
# compare sc result with 0
cmpwi cr7, 3, 0
@@ -58,8 +46,7 @@ cmpwi cr7, 3, 0
bne cr7, 2f
#else: we're the child
-#call funcptr
-# move arg (d) into r3
+#call funcptr: move arg (d) into r3
mr 3, 31
#move r30 (funcptr) into CTR reg
mtctr 30
@@ -72,12 +59,9 @@ sc
2:
# restore stack
-lwz 30, 12(1)
-lwz 31, 8(1)
+lwz 30, 0(1)
+lwz 31, 4(1)
addi 1, 1, 16
blr
-
-
-