klibc - Jan 2019 - [PATCH klibc 0/2] Fix i386 build

This series fixes link/load issues I found on i386 with Debian's
toolchain (gcc 8 with PIE as default, binutils 2.31).

Ben.

Ben Hutchings (2):
  [klibc] i386: Use -Ttext-segment to avoid address collision
  [klibc] Disable PIE

 scripts/Kbuild.klibc        | 3 ++-
 usr/klibc/arch/i386/MCONFIG | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

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Building klibc for i386 with binutils 2.31 adds an extra
.note.gnu.property section to klibc.so, the address of which is not
affected by the -Ttext option.  Loading a klibc executable then
fails with the following kernel log message:

9409 (sh.shared): Uhuuh, elf segment at 0000000000600000 requested but the
memory is mapped already

I don't exactly see why this is happening, but it is triggered by the
new section and the collision can be avoided by passing -Ttext-segment
instead of -Ttext, similarly to x86_64.

Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
 usr/klibc/arch/i386/MCONFIG | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usr/klibc/arch/i386/MCONFIG b/usr/klibc/arch/i386/MCONFIG
index 1150ecedf799..bfec004a3c8b 100644
--- a/usr/klibc/arch/i386/MCONFIG
+++ b/usr/klibc/arch/i386/MCONFIG
@@ -30,7 +30,7 @@ KLIBCBITSIZE  = 32
 # This address needs to be reachable using normal inter-module
 # calls, and work on the memory models for this architecture
 # 96 MB - normal binaries start at 128 MB
-KLIBCSHAREDFLAGS	= -Ttext 0x06000200
+KLIBCSHAREDFLAGS	= -Ttext-segment 0x06000000
 
 # Asm includes for i386 are in the merged x86 tree
 KLIBCARCHINCFLAGS = -I$(KLIBCKERNELOBJ)/arch/x86/include

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We link all executables as non-relocatable, so it makes no sense to
generate PIE code.  In addition, PIE code on i386 requires a working
GOT which we don't generate.

Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
 scripts/Kbuild.klibc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/Kbuild.klibc b/scripts/Kbuild.klibc
index f147a37309e3..35c375edd909 100644
--- a/scripts/Kbuild.klibc
+++ b/scripts/Kbuild.klibc
@@ -67,7 +67,8 @@ include $(srctree)/scripts/Kbuild.include
 # ---------------------------------------------------------------------------
 
 KLIBCREQFLAGS     := $(call cc-option, -fno-stack-protector, ) \
-                     $(call cc-option, -fwrapv, )
+                     $(call cc-option, -fwrapv, ) \
+                     $(call cc-option, -fno-PIE, )
 KLIBCARCHREQFLAGS : KLIBCOPTFLAGS     : KLIBCWARNFLAGS    := -W -Wall
-Wno-sign-compare -Wno-unused-parameter
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