[klibc] Re: got pointer wrong in shared klibc binary
Alan Modra
amodra at bigpond.net.au
Wed Sep 15 13:45:49 PDT 2004
On Wed, Sep 15, 2004 at 10:48:02AM +0930, Alan Modra wrote:
> After using SHAREDFLAGS = -Ttext 0x0f000200 on ppc64 (which I see you
> suggested in another email), I see the problem you're talking about.
>
> klibc is fundamentally broken on ppc64. You just can't call into
> another chunk of code (klibc.so in this case) which has a separate toc
> and expect things to work.
>
> You *might* get something working by copying the klibc.so .toc section
> into each app linking to klibc.so.
Well, the Horrible Hack does seem to work for me. Attached is a diff,
including a fix for setjmp.S too. stmw/lmw only save the low 32 bits
so can't really be used, and stmd/lmd aren't available.
--
Alan Modra
IBM OzLabs - Linux Technology Centre
-------------- next part --------------
diff -urpN klibc-0.173/MCONFIG klibc/MCONFIG
--- klibc-0.173/MCONFIG 2004-07-02 09:09:19.000000000 +0930
+++ klibc/MCONFIG 2004-09-15 11:54:05.258092171 +0930
@@ -19,6 +22,7 @@ RANLIB = $(CROSS)ranlib
NM = $(CROSS)nm
PERL = perl
STRIP = $(CROSS)strip --strip-all -R .comment -R .note
+OBJCOPY = $(CROSS)objcopy
HOST_CC = gcc
HOST_CFLAGS = -g -O
diff -urpN klibc-0.173/klibc/Makefile klibc/klibc/Makefile
--- klibc-0.173/klibc/Makefile 2004-08-26 15:33:41.000000000 +0930
+++ klibc/klibc/Makefile 2004-09-15 11:54:06.301925693 +0930
@@ -57,6 +57,8 @@ SOHASH = klibc.so
CRT0 = crt0.o
LIB = libc.a
+INTERP_O = interp.o
+
all: tests $(CRT0) $(LIB) $(SOLIB) klibc.so
# Add any architecture-specific rules
@@ -109,7 +111,7 @@ $(SOHASH): $(SOLIB) $(SOLIB).hash
rm -f klibc-??????????????????????.so
ln -f $@ klibc-`cat $(SOLIB).hash`.so
-interp.o: interp.S $(SOLIB).hash
+$(INTERP_O): interp.S $(SOLIB).hash
$(CC) $(CFLAGS) -D__ASSEMBLY__ -DLIBDIR=\"$(SHLIBDIR)\" \
-DSOHASH=\"`cat $(SOLIB).hash`\" \
-c -o $@ $<
diff -urpN klibc-0.173/klibc/arch/ppc64/MCONFIG klibc/klibc/arch/ppc64/MCONFIG
--- klibc-0.173/klibc/arch/ppc64/MCONFIG 2002-08-13 13:34:47.000000000 +0930
+++ klibc/klibc/arch/ppc64/MCONFIG 2004-09-15 09:22:01.452221449 +0930
@@ -9,3 +9,10 @@
OPTFLAGS = -Os -fomit-frame-pointer
BITSIZE = 64
+
+# Extra linkflags when building the shared version of the library
+# This address needs to be reachable using normal inter-module
+# calls, and work on the memory models for this architecture
+# 256-16 MB - normal binaries start at 256 MB, and jumps are limited
+# to +/- 16 MB
+SHAREDFLAGS = -Ttext 0x0f000200
diff -urpN klibc-0.173/klibc/arch/ppc64/Makefile.inc klibc/klibc/arch/ppc64/Makefile.inc
--- klibc-0.173/klibc/arch/ppc64/Makefile.inc 2004-06-07 16:25:06.000000000 +0930
+++ klibc/klibc/arch/ppc64/Makefile.inc 2004-09-15 12:10:35.090216287 +0930
@@ -13,4 +13,13 @@ ARCHOBJS = \
ARCHSOOBJS = $(patsubst %.o,%.lo,$(ARCHOBJS))
+INTERP_O = interp1.o
+
+interp.o: interp1.o klibc.got
+ $(LD) $(LDFLAGS) -r -o $@ interp1.o klibc.got
+
+klibc.got: $(SOHASH)
+ $(OBJCOPY) -j.got $< $@
+
archclean:
+ rm -f klibc.got
diff -urpN klibc-0.173/klibc/arch/ppc64/setjmp.S klibc/klibc/arch/ppc64/setjmp.S
--- klibc-0.173/klibc/arch/ppc64/setjmp.S 2003-12-13 14:09:13.000000000 +1030
+++ klibc/klibc/arch/ppc64/setjmp.S 2004-09-15 12:28:42.160328339 +0930
@@ -17,13 +16,33 @@ setjmp:
.globl setjmp
.globl .setjmp
.setjmp:
- mflr %r11 /* save return address */
- mfcr %r12 /* save condition register */
- mr %r10,%r1 /* save stack pointer */
- mr %r9,%r2 /* save GPR2 (not needed) */
- stmw %r9,0(%r3) /* save r9..r31 */
- li %r3,0 /* indicate success */
- blr /* return */
+ mflr %r11 /* save return address */
+ mfcr %r12 /* save condition register */
+ std %r2,0(%r3) /* save TOC pointer (not needed) */
+ stdu %r1,8(%r3) /* save stack pointer */
+ stdu %r11,8(%r3)
+ stdu %r12,8(%r3)
+ stdu %r13,8(%r3) /* save caller saved regs */
+ stdu %r14,8(%r3)
+ stdu %r15,8(%r3)
+ stdu %r16,8(%r3)
+ stdu %r17,8(%r3)
+ stdu %r18,8(%r3)
+ stdu %r19,8(%r3)
+ stdu %r20,8(%r3)
+ stdu %r21,8(%r3)
+ stdu %r22,8(%r3)
+ stdu %r23,8(%r3)
+ stdu %r24,8(%r3)
+ stdu %r25,8(%r3)
+ stdu %r26,8(%r3)
+ stdu %r27,8(%r3)
+ stdu %r28,8(%r3)
+ stdu %r29,8(%r3)
+ stdu %r30,8(%r3)
+ std %r31,8(%r3)
+ li %r3,0 /* indicate success */
+ blr /* return */
.size .setjmp,.-.setjmp
.section ".opd","aw"
@@ -35,12 +54,32 @@ longjmp:
.globl longjmp
.globl .longjmp
.longjmp:
- lmw %r9,0(%r3) /* save r9..r31 */
- mtlr %r11 /* restore LR */
- mtcr %r12 /* restore CR */
- mr %r2,%r9 /* restore GPR2 (not needed) */
- mr %r1,%r10 /* restore stack */
- mr %r3,%r4 /* get return value */
- blr /* return */
+ ld %r2,0(%r3) /* restore TOC pointer (not needed) */
+ ldu %r1,8(%r3) /* restore stack */
+ ldu %r11,8(%r3)
+ ldu %r12,8(%r3)
+ ldu %r13,8(%r3) /* restore caller saved regs */
+ ldu %r14,8(%r3)
+ ldu %r15,8(%r3)
+ ldu %r16,8(%r3)
+ ldu %r17,8(%r3)
+ ldu %r18,8(%r3)
+ ldu %r19,8(%r3)
+ ldu %r20,8(%r3)
+ ldu %r21,8(%r3)
+ ldu %r22,8(%r3)
+ ldu %r23,8(%r3)
+ ldu %r24,8(%r3)
+ ldu %r25,8(%r3)
+ ldu %r26,8(%r3)
+ ldu %r27,8(%r3)
+ ldu %r28,8(%r3)
+ ldu %r29,8(%r3)
+ ldu %r30,8(%r3)
+ ld %r31,8(%r3)
+ mtlr %r11 /* restore LR */
+ mtcr %r12 /* restore CR */
+ mr %r3,%r4 /* get return value */
+ blr /* return */
.size .longjmp,.-.longjmp
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