diff options
| author | Michael Ellerman | 2022-09-16 14:41:24 +1000 |
|---|---|---|
| committer | Michael Ellerman | 2022-09-26 20:58:16 +1000 |
| commit | b150a4d12b919baf956b807aa305cf78df03d0fe (patch) | |
| tree | ba2cae6103c8ce646db2b7dc93dd48912c21a77b | |
| parent | 331771e836e6a32c8632d8cf5e2cdd94471258ad (diff) | |
powerpc/vmlinux.lds: Add an explicit symbol for the SRWX boundary
Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after boot) code
and data.
But that's a little subtle, so add an explicit symbol to document that
the SRWX boundary lies there, and add a comment making it clear that
__init_begin must also begin there.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-2-mpe@ellerman.id.au
| -rw-r--r-- | arch/powerpc/include/asm/sections.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/vmlinux.lds.S | 9 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/mmu.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 4 |
4 files changed, 11 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index babda2677b30..9c00c9c0ca8f 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -13,6 +13,7 @@ typedef struct func_desc func_desc_t; #include <asm-generic/sections.h> extern char __head_end[]; +extern char __srwx_boundary[]; /* Patch sites */ extern s32 patch__call_flush_branch_caches1; diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index dacf8b4302d9..29d891329856 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -214,11 +214,16 @@ SECTIONS } #endif + /* + * Various code relies on __init_begin being at the strict RWX boundary. + */ + . = ALIGN(STRICT_ALIGN_SIZE); + __srwx_boundary = .; + __init_begin = .; + /* * Init sections discarded at runtime */ - . = ALIGN(STRICT_ALIGN_SIZE); - __init_begin = .; .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { _sinittext = .; INIT_TEXT diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c index a96b73006dfb..250d174459d4 100644 --- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -158,7 +158,7 @@ static unsigned long __init __mmu_mapin_ram(unsigned long base, unsigned long to unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) { unsigned long done; - unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; + unsigned long border = (unsigned long)__srwx_boundary - PAGE_OFFSET; unsigned long size; size = roundup_pow_of_two((unsigned long)_einittext - PAGE_OFFSET); diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index 698274109c91..9f880f91f584 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -259,8 +259,8 @@ print_mapping(unsigned long start, unsigned long end, unsigned long size, bool e static unsigned long next_boundary(unsigned long addr, unsigned long end) { #ifdef CONFIG_STRICT_KERNEL_RWX - if (addr < __pa_symbol(__init_begin)) - return __pa_symbol(__init_begin); + if (addr < __pa_symbol(__srwx_boundary)) + return __pa_symbol(__srwx_boundary); #endif return end; } |