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350 lines
17 KiB
350 lines
17 KiB
commit 89b638f48ac5c9af5b1fe9caa6287d70127b66a5 |
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Author: Stefan Liebler <stli@linux.ibm.com> |
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Date: Tue May 17 16:12:18 2022 +0200 |
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S390: Enable static PIE |
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This commit enables static PIE on 64bit. On 31bit, static PIE is |
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not supported. |
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A new configure check in sysdeps/s390/s390-64/configure.ac also performs |
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a minimal test for requirements in ld: |
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Ensure you also have those patches for: |
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- binutils (ld) |
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- "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE" |
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https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9 |
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(Tested by configure check above) |
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Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to |
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be processed in _dl_relocate_static_pie() as static TLS map is not setup. |
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- "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie" |
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https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e |
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(We can't test it in configure as we are not able to link a static PIE |
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executable if the system glibc lacks static PIE support) |
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Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries |
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and the IFUNC symbols are not processed, which leads to crashes. |
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|
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- kernel (the mentioned links to the commits belong to 5.19 merge window): |
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- "s390/mmap: increase stack/mmap gap to 128MB" |
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https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2 |
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- "s390/vdso: move vdso mapping to its own function" |
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https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8 |
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- "s390/vdso: map vdso above stack" |
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https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033 |
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- "s390/vdso: add vdso randomization" |
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https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25 |
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(We can't test the kernel of the target system) |
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Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0), |
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static PIE executables like ldconfig will crash. While startup sbrk is |
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used to enlarge the HEAP. Unfortunately the underlying brk syscall fails |
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as there is not enough space after the HEAP. Then the address of the TLS |
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image is invalid and the following memcpy in __libc_setup_tls() leads |
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to a segfault. |
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If /proc/sys/kernel/randomize_va_space is activated (default: 2), there |
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is enough space after HEAP. |
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|
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- glibc |
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- "Linux: Define MMAP_CALL_INTERNAL" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb |
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- "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402 |
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- "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff |
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- "ia64: Always define IA64_USE_NEW_STUB as a flag macro" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64 |
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- "Linux: Implement a useful version of _startup_fatal" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31 |
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- "Linux: Introduce __brk_call for invoking the brk system call" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa |
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- "csu: Implement and use _dl_early_allocate during static startup" |
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https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7 |
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The mentioned patch series by Florian Weimer avoids the mentioned failing |
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sbrk syscall by falling back to mmap. |
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This commit also adjusts startup code in start.S to be ready for static PIE. |
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We have to add a wrapper function for main as we are not allowed to use |
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GOT relocations before __libc_start_main is called. |
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(Compare also to: |
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- commit 14d886edbd3d80b771e1c42fbd9217f9074de9c6 |
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"aarch64: fix start code for static pie" |
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- commit 3d1d79283e6de4f7c434cb67fb53a4fd28359669 |
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"aarch64: fix static pie enabled libc when main is in a shared library" |
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) |
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(cherry picked from commit 728894dba4a19578bd803906de184a8dd51ed13c) |
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diff --git a/sysdeps/s390/s390-64/configure b/sysdeps/s390/s390-64/configure |
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new file mode 100644 |
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index 0000000000000000..101c570d2e62da25 |
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--- /dev/null |
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+++ b/sysdeps/s390/s390-64/configure |
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@@ -0,0 +1,122 @@ |
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+# This file is generated from configure.ac by Autoconf. DO NOT EDIT! |
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+ # Local configure fragment for sysdeps/s390/s390-64. |
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+ |
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+# Minimal checking for static PIE support in ld. |
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+# Compare to ld testcase/bugzilla: |
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+# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd |
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+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for s390-specific static PIE requirements" >&5 |
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+$as_echo_n "checking for s390-specific static PIE requirements... " >&6; } |
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+if { as_var=\ |
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+libc_cv_s390x_staticpie_req; eval \${$as_var+:} false; }; then : |
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+ $as_echo_n "(cached) " >&6 |
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+else |
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+ cat > conftest1.c <<EOF |
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+__thread int * foo; |
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+ |
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+void |
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+bar (void) |
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+{ |
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+ *foo = 1; |
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+} |
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+EOF |
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+ cat > conftest2.c <<EOF |
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+extern __thread int *foo; |
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+extern void bar (void); |
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+static int x; |
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+ |
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+int |
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+main () |
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+{ |
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+ foo = &x; |
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+ return 0; |
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+} |
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+EOF |
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+ libc_cv_s390x_staticpie_req=no |
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+ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o' |
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+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 |
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+ (eval $ac_try) 2>&5 |
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+ ac_status=$? |
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+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 |
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+ test $ac_status = 0; }; } \ |
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+ && { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest2.c -o conftest2.o' |
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+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 |
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+ (eval $ac_try) 2>&5 |
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+ ac_status=$? |
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+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 |
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+ test $ac_status = 0; }; } \ |
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+ && { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -pie -o conftest conftest1.o conftest2.o' |
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+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 |
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+ (eval $ac_try) 2>&5 |
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+ ac_status=$? |
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+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 |
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+ test $ac_status = 0; }; } \ |
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+ && { ac_try='! readelf -Wr conftest | grep R_390_TLS_TPOFF' |
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+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 |
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+ (eval $ac_try) 2>&5 |
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+ ac_status=$? |
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+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 |
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+ test $ac_status = 0; }; } |
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+ then |
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+ libc_cv_s390x_staticpie_req=yes |
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+ fi |
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+ rm -rf conftest.* |
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+fi |
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+eval ac_res=\$\ |
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+libc_cv_s390x_staticpie_req |
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+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 |
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+$as_echo "$ac_res" >&6; } |
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+if test $libc_cv_s390x_staticpie_req = yes; then |
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+ # Static PIE is supported only on 64bit. |
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+ # Ensure you also have those patches for: |
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+ # - binutils (ld) |
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+ # - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE" |
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+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9 |
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+ # (Tested by configure check above) |
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+ # Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to |
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+ # be processed in _dl_relocate_static_pie() as static TLS map is not setup. |
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+ # - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie" |
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+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e |
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+ # (We can't test it in configure as we are not able to link a static PIE |
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+ # executable if the system glibc lacks static PIE support) |
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+ # Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries |
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+ # and the IFUNC symbols are not processed, which leads to crashes. |
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+ # |
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+ # - kernel (the mentioned links to the commits belong to 5.19 merge window): |
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+ # - "s390/mmap: increase stack/mmap gap to 128MB" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2 |
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+ # - "s390/vdso: move vdso mapping to its own function" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8 |
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+ # - "s390/vdso: map vdso above stack" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033 |
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+ # - "s390/vdso: add vdso randomization" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25 |
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+ # (We can't test the kernel of the target system) |
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+ # Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0), |
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+ # static PIE executables like ldconfig will crash. While startup sbrk is |
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+ # used to enlarge the HEAP. Unfortunately the underlying brk syscall fails |
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+ # as there is not enough space after the HEAP. Then the address of the TLS |
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+ # image is invalid and the following memcpy in __libc_setup_tls() leads |
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+ # to a segfault. |
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+ # If /proc/sys/kernel/randomize_va_space is activated (default: 2), there |
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+ # is enough space after HEAP. |
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+ # |
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+ # - glibc |
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+ # - "Linux: Define MMAP_CALL_INTERNAL" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb |
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+ # - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402 |
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+ # - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff |
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+ # - "ia64: Always define IA64_USE_NEW_STUB as a flag macro" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64 |
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+ # - "Linux: Implement a useful version of _startup_fatal" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31 |
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+ # - "Linux: Introduce __brk_call for invoking the brk system call" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa |
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+ # - "csu: Implement and use _dl_early_allocate during static startup" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7 |
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+ # The mentioned patch series by Florian Weimer avoids the mentioned failing |
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+ # sbrk syscall by falling back to mmap. |
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+ $as_echo "#define SUPPORT_STATIC_PIE 1" >>confdefs.h |
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+ |
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+fi |
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diff --git a/sysdeps/s390/s390-64/configure.ac b/sysdeps/s390/s390-64/configure.ac |
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new file mode 100644 |
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index 0000000000000000..2583a4a3350ac11f |
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--- /dev/null |
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+++ b/sysdeps/s390/s390-64/configure.ac |
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@@ -0,0 +1,92 @@ |
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+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory. |
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+# Local configure fragment for sysdeps/s390/s390-64. |
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+ |
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+# Minimal checking for static PIE support in ld. |
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+# Compare to ld testcase/bugzilla: |
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+# <binutils-source>/ld/testsuite/ld-elf/pr22263-1.rd |
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+AC_CACHE_CHECK([for s390-specific static PIE requirements], \ |
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+[libc_cv_s390x_staticpie_req], [dnl |
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+ cat > conftest1.c <<EOF |
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+__thread int * foo; |
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+ |
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+void |
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+bar (void) |
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+{ |
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+ *foo = 1; |
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+} |
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+EOF |
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+ cat > conftest2.c <<EOF |
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+extern __thread int *foo; |
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+extern void bar (void); |
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+static int x; |
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+ |
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+int |
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+main () |
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+{ |
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+ foo = &x; |
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+ return 0; |
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+} |
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+EOF |
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+ libc_cv_s390x_staticpie_req=no |
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+ if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest1.c -o conftest1.o]) \ |
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+ && AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -fPIE -c conftest2.c -o conftest2.o]) \ |
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+ && AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -pie -o conftest conftest1.o conftest2.o]) \ |
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+ && AC_TRY_COMMAND([! readelf -Wr conftest | grep R_390_TLS_TPOFF]) |
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+ then |
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+ libc_cv_s390x_staticpie_req=yes |
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+ fi |
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+ rm -rf conftest.*]) |
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+if test $libc_cv_s390x_staticpie_req = yes; then |
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+ # Static PIE is supported only on 64bit. |
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+ # Ensure you also have those patches for: |
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+ # - binutils (ld) |
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+ # - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE" |
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+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9 |
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+ # (Tested by configure check above) |
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+ # Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to |
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+ # be processed in _dl_relocate_static_pie() as static TLS map is not setup. |
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+ # - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie" |
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+ # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e |
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+ # (We can't test it in configure as we are not able to link a static PIE |
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+ # executable if the system glibc lacks static PIE support) |
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+ # Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries |
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+ # and the IFUNC symbols are not processed, which leads to crashes. |
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+ # |
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+ # - kernel (the mentioned links to the commits belong to 5.19 merge window): |
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+ # - "s390/mmap: increase stack/mmap gap to 128MB" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2 |
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+ # - "s390/vdso: move vdso mapping to its own function" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8 |
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+ # - "s390/vdso: map vdso above stack" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033 |
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+ # - "s390/vdso: add vdso randomization" |
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+ # https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25 |
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+ # (We can't test the kernel of the target system) |
|
+ # Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0), |
|
+ # static PIE executables like ldconfig will crash. While startup sbrk is |
|
+ # used to enlarge the HEAP. Unfortunately the underlying brk syscall fails |
|
+ # as there is not enough space after the HEAP. Then the address of the TLS |
|
+ # image is invalid and the following memcpy in __libc_setup_tls() leads |
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+ # to a segfault. |
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+ # If /proc/sys/kernel/randomize_va_space is activated (default: 2), there |
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+ # is enough space after HEAP. |
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+ # |
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+ # - glibc |
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+ # - "Linux: Define MMAP_CALL_INTERNAL" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb |
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+ # - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402 |
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+ # - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff |
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+ # - "ia64: Always define IA64_USE_NEW_STUB as a flag macro" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64 |
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+ # - "Linux: Implement a useful version of _startup_fatal" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31 |
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+ # - "Linux: Introduce __brk_call for invoking the brk system call" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa |
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+ # - "csu: Implement and use _dl_early_allocate during static startup" |
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+ # https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7 |
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+ # The mentioned patch series by Florian Weimer avoids the mentioned failing |
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+ # sbrk syscall by falling back to mmap. |
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+ AC_DEFINE(SUPPORT_STATIC_PIE) |
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+fi |
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diff --git a/sysdeps/s390/s390-64/start.S b/sysdeps/s390/s390-64/start.S |
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index 4e6526308aee3c00..b4a66e4a97b83397 100644 |
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--- a/sysdeps/s390/s390-64/start.S |
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+++ b/sysdeps/s390/s390-64/start.S |
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@@ -85,10 +85,25 @@ _start: |
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|
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/* Ok, now branch to the libc main routine. */ |
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#ifdef PIC |
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+# ifdef SHARED |
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+ /* Used for dynamic linked position independent executable. |
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+ => Scrt1.o */ |
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larl %r2,main@GOTENT # load pointer to main |
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lg %r2,0(%r2) |
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+# else |
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+ /* Used for dynamic linked position dependent executable. |
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+ => crt1.o (glibc configured without --disable-default-pie: |
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+ PIC is defined) |
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+ Or for static linked position independent executable. |
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+ => rcrt1.o (only available if glibc configured without |
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+ --disable-default-pie: PIC is defined) */ |
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+ larl %r2,__wrap_main |
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+# endif |
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brasl %r14,__libc_start_main@plt |
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#else |
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+ /* Used for dynamic/static linked position dependent executable. |
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+ => crt1.o (glibc configured with --disable-default-pie: |
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+ PIC and SHARED are not defined) */ |
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larl %r2,main # load pointer to main |
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brasl %r14,__libc_start_main |
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#endif |
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@@ -98,6 +113,19 @@ _start: |
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|
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cfi_endproc |
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|
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+#if defined PIC && !defined SHARED |
|
+ /* When main is not defined in the executable but in a shared library |
|
+ then a wrapper is needed in crt1.o of the static-pie enabled libc, |
|
+ because crt1.o and rcrt1.o share code and the later must avoid the |
|
+ use of GOT relocations before __libc_start_main is called. */ |
|
+__wrap_main: |
|
+ cfi_startproc |
|
+ larl %r1,main@GOTENT # load pointer to main |
|
+ lg %r1,0(%r1) |
|
+ br %r1 |
|
+ cfi_endproc |
|
+#endif |
|
+ |
|
/* Define a symbol for the first piece of initialized data. */ |
|
.data |
|
.globl __data_start
|
|
|