glibc/csu/Makefile, branch master

Add crt1-2.0.o for glibc 2.0 compatibility tests

2024-05-06T14:49:40Z

Starting from glibc 2.1, crt1.o contains _IO_stdin_used which is checked by _IO_check_libio to provide binary compatibility for glibc 2.0. Add crt1-2.0.o for tests against glibc 2.0. Define tests-2.0 for glibc 2.0 compatibility tests. Add and update glibc 2.0 compatibility tests for stderr, matherr and pthread_kill. Reviewed-by: Carlos O'Donell

csu: Reformat Makefile.

2024-02-25T18:38:16Z

Reflow and sort Makefile. Code generation changes present due to link order changes. No regressions on x86_64 and i686.

Update copyright dates with scripts/update-copyrights

2024-01-01T18:53:40Z

Update copyright dates with scripts/update-copyrights

2023-01-06T21:14:39Z

csu: Disable stack protector for static-reloc for static-pie

2022-10-06T15:52:46Z

For instance on x86_64 with gcc 12.1.1 andwith fstack-protector enabled the empty function still generates a stack protector code sequence: 0000000000000000 <_dl_relocate_static_pie>: 0: 48 83 ec 18 sub $0x18,%rsp 4: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax b: 00 00 d: 48 89 44 24 08 mov %rax,0x8(%rsp) 12: 31 c0 xor %eax,%eax 14: 48 8b 44 24 08 mov 0x8(%rsp),%rax 19: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 20: 00 00 22: 75 05 jne 29 <_dl_relocate_static_pie+0x29> 24: 48 83 c4 18 add $0x18,%rsp 28: c3 ret 29: e8 00 00 00 00 call 2e <_dl_relocate_static_pie+0x2e> And since the function is called prior thread pointer setup, it triggers a invalid memory access (this is shown with the failure of elf/tst-tls1-static-non-pie). Although it might characterizes as compiler issue or missed optimization, to be safe also disables stack protector on static-reloc object. Checked on x86_64-linux-gnu and sparc64-linux-gnu. Reviewed-by: Siddhesh Poyarekar

Update copyright dates with scripts/update-copyrights

2022-01-01T19:40:24Z

I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines

hurd: Add rules for static PIE build

2021-12-11T23:42:13Z

This fixes [BZ #28671].

Extend struct r_debug to support multiple namespaces [BZ #15971]

2021-09-19T20:51:35Z

Glibc does not provide an interface for debugger to access libraries loaded in multiple namespaces via dlmopen. The current rtld-debugger interface is described in the file: elf/rtld-debugger-interface.txt under the "Standard debugger interface" heading. This interface only provides access to the first link-map (LM_ID_BASE). 1. Bump r_version to 2 when multiple namespaces are used. This triggers the GDB bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28236 2. Add struct r_debug_extended to extend struct r_debug into a linked-list, where each element correlates to an unique namespace. 3. Initialize the r_debug_extended structure. Bump r_version to 2 for the new namespace and add the new namespace to the namespace linked list. 4. Add _dl_debug_update to return the address of struct r_debug' of a namespace. 5. Add a hidden symbol, _r_debug_extended, for struct r_debug_extended. 6. Provide the symbol, _r_debug, with size of struct r_debug, as an alias of _r_debug_extended, for programs which reference _r_debug. This fixes BZ #15971. Reviewed-by: Florian Weimer

Build libc-start with stack protector for SHARED

2021-03-15T14:55:00Z

This does not change the emitted code since __libc_start_main does not return, but is important for formal flags compliance. This also cleans up the cosmetic inconsistency in the stack protector flags in csu, especially the incorrect value of STACK_PROTECTOR_LEVEL. Reviewed-by: Adhemerval Zanella

Reduce the statically linked startup code [BZ #23323]

2021-02-25T11:13:02Z

It turns out the startup code in csu/elf-init.c has a perfect pair of ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A New Method to Bypass 64-bit Linux ASLR"). These functions are not needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY are already processed by the dynamic linker. However, the dynamic linker skipped the main program for some reason. For maximum backwards compatibility, this is not changed, and instead, the main map is consulted from __libc_start_main if the init function argument is a NULL pointer. For statically linked binaries, the old approach based on linker symbols is still used because there is nothing else available. A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because new binaries running on an old libc would not run their ELF constructors, leading to difficult-to-debug issues.