* Committed: fix PR ld/20125, MMIX weak symbols
@ 2017-08-21 2:25 Hans-Peter Nilsson
2017-09-14 3:11 ` Hans-Peter Nilsson
0 siblings, 1 reply; 2+ messages in thread
From: Hans-Peter Nilsson @ 2017-08-21 2:25 UTC (permalink / raw)
To: binutils
Reloc-management for weak undefined symbols with PUSHJ relocs (jump
stubs for an out-of-range call operand) "lost" the reloc, causing
internal inconsistencies and an abort. Fixed thusly, finally.
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 79dfa1d..6badc5d 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
+
+ PR ld/20125
+ * elf64-mmix.c (mmix_elf_relax_section): Correct handling of
+ undefined weak symbols.
+
2017-08-18 Nick Clifton <nickc@redhat.com>
PR binutils/21962
diff --git a/bfd/elf64-mmix.c b/bfd/elf64-mmix.c
index 8c8e06d..8d79d39 100644
--- a/bfd/elf64-mmix.c
+++ b/bfd/elf64-mmix.c
@@ -2710,8 +2710,21 @@ mmix_elf_relax_section (bfd *abfd,
indx = ELF64_R_SYM (irel->r_info) - symtab_hdr->sh_info;
h = elf_sym_hashes (abfd)[indx];
BFD_ASSERT (h != NULL);
- if (h->root.type != bfd_link_hash_defined
- && h->root.type != bfd_link_hash_defweak)
+ if (h->root.type == bfd_link_hash_undefweak)
+ /* FIXME: for R_MMIX_PUSHJ_STUBBABLE, there are alternatives to
+ the canonical value 0 for an unresolved weak symbol to
+ consider: as the debug-friendly approach, resolve to "abort"
+ (or a port-specific function), or as the space-friendly
+ approach resolve to the next instruction (like some other
+ ports, notably ARM and AArch64). These alternatives require
+ matching code in mmix_elf_perform_relocation or its caller. */
+ symval = 0;
+ else if (h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ symval = (h->root.u.def.value
+ + h->root.u.def.section->output_section->vma
+ + h->root.u.def.section->output_offset);
+ else
{
/* This appears to be a reference to an undefined symbol. Just
ignore it--it will be caught by the regular reloc processing.
@@ -2725,10 +2738,6 @@ mmix_elf_relax_section (bfd *abfd,
}
continue;
}
-
- symval = (h->root.u.def.value
- + h->root.u.def.section->output_section->vma
- + h->root.u.def.section->output_offset);
}
if (ELF64_R_TYPE (irel->r_info) == (int) R_MMIX_PUSHJ_STUBBABLE)
@@ -2866,6 +2875,8 @@ mmix_elf_relax_section (bfd *abfd,
}
}
+ BFD_ASSERT(pjsno == mmix_elf_section_data (sec)->pjs.n_pushj_relocs);
+
if (internal_relocs != NULL
&& elf_section_data (sec)->relocs != internal_relocs)
free (internal_relocs);
diff --git a/ld/ChangeLog b/ld/ChangeLog
index ba576c2..a150256 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
+
+ PR ld/20125
+ * testsuite/ld-mmix/pr20125.d, testsuite/ld-mmix/pr20125.s: New
+ test.
+
2017-08-20 A. Wilcox <awilfox@adelielinux.org>
PR ld/21976
diff --git a/ld/testsuite/ld-mmix/pr20125.d b/ld/testsuite/ld-mmix/pr20125.d
new file mode 100644
index 0000000..7c09c04
--- /dev/null
+++ b/ld/testsuite/ld-mmix/pr20125.d
@@ -0,0 +1,21 @@
+#as: -no-predefined-syms -x -I$srcdir/$subdir
+#ld: -m mmo --defsym __.MMIX.start..text=0x80000
+#objdump: -dr
+
+# PUSHJ reloc handling was wrong for weak undefined symbols, causing
+# internal inconsistencies, leading to a call to abort.
+# Note that we don't keep track of which symbols have pushj-stubs, so
+# we get one stub each for the two calls to "foo".
+
+.*: file format mmo
+
+Disassembly of section \.text:
+
+0+80000 <(_start|Main)>:
+ 80000: fe000004 get \$0,rJ
+ 80004: f2010004 pushj \$1,80014 <Main\+0x14>
+ 80008: f2010004 pushj \$1,80018 <Main\+0x18>
+ 8000c: f6040000 put rJ,\$0
+ 80010: f8010000 pop 1,0
+ 80014: f1fdfffb jmp 0 <Main-0x80000>
+ 80018: f1fdfffa jmp 0 <Main-0x80000>
diff --git a/ld/testsuite/ld-mmix/pr20125.s b/ld/testsuite/ld-mmix/pr20125.s
new file mode 100644
index 0000000..e528d9d
--- /dev/null
+++ b/ld/testsuite/ld-mmix/pr20125.s
@@ -0,0 +1,2 @@
+ .weak bar
+ .include "pr12815-2.s"
brgds, H-P
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Committed: fix PR ld/20125, MMIX weak symbols
2017-08-21 2:25 Committed: fix PR ld/20125, MMIX weak symbols Hans-Peter Nilsson
@ 2017-09-14 3:11 ` Hans-Peter Nilsson
0 siblings, 0 replies; 2+ messages in thread
From: Hans-Peter Nilsson @ 2017-09-14 3:11 UTC (permalink / raw)
To: binutils
Now also imported onto the 2.29 branch. I found that 0a79bef4
was a prerequisite to build, so imported and pushed too.
binutils:
* dwarf.c (display_debug_names): Initialize hash_prev.
On Sun, 20 Aug 2017, Hans-Peter Nilsson wrote:
> Reloc-management for weak undefined symbols with PUSHJ relocs (jump
> stubs for an out-of-range call operand) "lost" the reloc, causing
> internal inconsistencies and an abort. Fixed thusly, finally.
>
> diff --git a/bfd/ChangeLog b/bfd/ChangeLog
> index 79dfa1d..6badc5d 100644
> --- a/bfd/ChangeLog
> +++ b/bfd/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
> +
> + PR ld/20125
> + * elf64-mmix.c (mmix_elf_relax_section): Correct handling of
> + undefined weak symbols.
> +
> 2017-08-18 Nick Clifton <nickc@redhat.com>
>
> PR binutils/21962
> diff --git a/bfd/elf64-mmix.c b/bfd/elf64-mmix.c
> index 8c8e06d..8d79d39 100644
> --- a/bfd/elf64-mmix.c
> +++ b/bfd/elf64-mmix.c
> @@ -2710,8 +2710,21 @@ mmix_elf_relax_section (bfd *abfd,
> indx = ELF64_R_SYM (irel->r_info) - symtab_hdr->sh_info;
> h = elf_sym_hashes (abfd)[indx];
> BFD_ASSERT (h != NULL);
> - if (h->root.type != bfd_link_hash_defined
> - && h->root.type != bfd_link_hash_defweak)
> + if (h->root.type == bfd_link_hash_undefweak)
> + /* FIXME: for R_MMIX_PUSHJ_STUBBABLE, there are alternatives to
> + the canonical value 0 for an unresolved weak symbol to
> + consider: as the debug-friendly approach, resolve to "abort"
> + (or a port-specific function), or as the space-friendly
> + approach resolve to the next instruction (like some other
> + ports, notably ARM and AArch64). These alternatives require
> + matching code in mmix_elf_perform_relocation or its caller. */
> + symval = 0;
> + else if (h->root.type == bfd_link_hash_defined
> + || h->root.type == bfd_link_hash_defweak)
> + symval = (h->root.u.def.value
> + + h->root.u.def.section->output_section->vma
> + + h->root.u.def.section->output_offset);
> + else
> {
> /* This appears to be a reference to an undefined symbol. Just
> ignore it--it will be caught by the regular reloc processing.
> @@ -2725,10 +2738,6 @@ mmix_elf_relax_section (bfd *abfd,
> }
> continue;
> }
> -
> - symval = (h->root.u.def.value
> - + h->root.u.def.section->output_section->vma
> - + h->root.u.def.section->output_offset);
> }
>
> if (ELF64_R_TYPE (irel->r_info) == (int) R_MMIX_PUSHJ_STUBBABLE)
> @@ -2866,6 +2875,8 @@ mmix_elf_relax_section (bfd *abfd,
> }
> }
>
> + BFD_ASSERT(pjsno == mmix_elf_section_data (sec)->pjs.n_pushj_relocs);
> +
> if (internal_relocs != NULL
> && elf_section_data (sec)->relocs != internal_relocs)
> free (internal_relocs);
> diff --git a/ld/ChangeLog b/ld/ChangeLog
> index ba576c2..a150256 100644
> --- a/ld/ChangeLog
> +++ b/ld/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-08-21 Hans-Peter Nilsson <hp@bitrange.com>
> +
> + PR ld/20125
> + * testsuite/ld-mmix/pr20125.d, testsuite/ld-mmix/pr20125.s: New
> + test.
> +
> 2017-08-20 A. Wilcox <awilfox@adelielinux.org>
>
> PR ld/21976
> diff --git a/ld/testsuite/ld-mmix/pr20125.d b/ld/testsuite/ld-mmix/pr20125.d
> new file mode 100644
> index 0000000..7c09c04
> --- /dev/null
> +++ b/ld/testsuite/ld-mmix/pr20125.d
> @@ -0,0 +1,21 @@
> +#as: -no-predefined-syms -x -I$srcdir/$subdir
> +#ld: -m mmo --defsym __.MMIX.start..text=0x80000
> +#objdump: -dr
> +
> +# PUSHJ reloc handling was wrong for weak undefined symbols, causing
> +# internal inconsistencies, leading to a call to abort.
> +# Note that we don't keep track of which symbols have pushj-stubs, so
> +# we get one stub each for the two calls to "foo".
> +
> +.*: file format mmo
> +
> +Disassembly of section \.text:
> +
> +0+80000 <(_start|Main)>:
> + 80000: fe000004 get \$0,rJ
> + 80004: f2010004 pushj \$1,80014 <Main\+0x14>
> + 80008: f2010004 pushj \$1,80018 <Main\+0x18>
> + 8000c: f6040000 put rJ,\$0
> + 80010: f8010000 pop 1,0
> + 80014: f1fdfffb jmp 0 <Main-0x80000>
> + 80018: f1fdfffa jmp 0 <Main-0x80000>
> diff --git a/ld/testsuite/ld-mmix/pr20125.s b/ld/testsuite/ld-mmix/pr20125.s
> new file mode 100644
> index 0000000..e528d9d
> --- /dev/null
> +++ b/ld/testsuite/ld-mmix/pr20125.s
> @@ -0,0 +1,2 @@
> + .weak bar
> + .include "pr12815-2.s"
>
> brgds, H-P
>
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2017-09-14 3:11 ` Hans-Peter Nilsson
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