diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/kernel/vmlinux.lds.S | 53 |
1 files changed, 50 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index b59d75e194a5..2d1cfafd1404 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -44,11 +44,58 @@ SECTIONS * Text, read only data and other permanent read-only sections */ - /* Text and gots */ + _text = .; + _stext = .; + + /* + * Head text. + * This needs to be in its own output section to avoid ld placing + * branch trampoline stubs randomly throughout the fixed sections, + * which it will do (even if the branch comes from another section) + * in order to optimize stub generation. + */ + .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { +#ifdef CONFIG_PPC64 + KEEP(*(.head.text.first_256B)); +#ifdef CONFIG_PPC_BOOK3E +# define END_FIXED 0x100 +#else + KEEP(*(.head.text.real_vectors)); + *(.head.text.real_trampolines); + KEEP(*(.head.text.virt_vectors)); + *(.head.text.virt_trampolines); +# if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV) + KEEP(*(.head.data.fwnmi_page)); +# define END_FIXED 0x8000 +# else +# define END_FIXED 0x7000 +# endif +#endif + ASSERT((. == END_FIXED), "vmlinux.lds.S: fixed section overflow error"); +#else /* !CONFIG_PPC64 */ + HEAD_TEXT +#endif + } :kernel + + /* + * If the build dies here, it's likely code in head_64.S is referencing + * labels it can't reach, and the linker inserting stubs without the + * assembler's knowledge. To debug, remove the above assert and + * rebuild. Look for branch stubs in the fixed section region. + * + * Linker stub generation could be allowed in "trampoline" + * sections if absolutely necessary, but this would require + * some rework of the fixed sections. Before resorting to this, + * consider references that have sufficient addressing range, + * (e.g., hand coded trampolines) so the linker does not have + * to add stubs. + * + * Linker stubs at the top of the main text section are currently not + * detected, and will result in a crash at boot due to offsets being + * wrong. + */ .text : AT(ADDR(.text) - LOAD_OFFSET) { ALIGN_FUNCTION(); - HEAD_TEXT - _text = .; /* careful! __ftr_alt_* sections need to be close to .text */ *(.text .fixup __ftr_alt_* .ref.text) SCHED_TEXT |