From 335de24e5e774aa94ff9551b3194fe15f52ea1d9 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 22 Nov 2023 23:18:12 +0100 Subject: modules: Ensure 64-bit alignment on __ksymtab_* sections On 64-bit architectures without CONFIG_HAVE_ARCH_PREL32_RELOCATIONS (e.g. ppc64, ppc64le, parisc, s390x,...) the __KSYM_REF() macro stores 64-bit pointers into the __ksymtab* sections. Make sure that those sections will be correctly aligned at module link time, otherwise unaligned memory accesses may happen at runtime. As per unaligned-memory-access [0] "unaligned memory accesses [...] will not work correctly on certain platforms and will cause performance problems on others", so fix this. The __kcrctab* sections store 32-bit entities, so use ALIGN(4) for those. Signed-off-by: Helge Deller [mcgrof: added unaligned-memory-access justification] Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/core-api/unaligned-memory-access.rst # [0] Signed-off-by: Luis Chamberlain --- scripts/module.lds.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'scripts/module.lds.S') diff --git a/scripts/module.lds.S b/scripts/module.lds.S index 3f43edef813c..23f9912179ce 100644 --- a/scripts/module.lds.S +++ b/scripts/module.lds.S @@ -18,10 +18,10 @@ SECTIONS { *(.export_symbol) } - __ksymtab 0 : { *(SORT(___ksymtab+*)) } - __ksymtab_gpl 0 : { *(SORT(___ksymtab_gpl+*)) } - __kcrctab 0 : { *(SORT(___kcrctab+*)) } - __kcrctab_gpl 0 : { *(SORT(___kcrctab_gpl+*)) } + __ksymtab 0 : ALIGN(8) { *(SORT(___ksymtab+*)) } + __ksymtab_gpl 0 : ALIGN(8) { *(SORT(___ksymtab_gpl+*)) } + __kcrctab 0 : ALIGN(4) { *(SORT(___kcrctab+*)) } + __kcrctab_gpl 0 : ALIGN(4) { *(SORT(___kcrctab_gpl+*)) } .ctors 0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) } .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) } -- cgit v1.2.3 From 03ddd2f17e28fe0e53a702469b1b751d40f5efbb Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 22 Nov 2023 23:18:14 +0100 Subject: modules: Add missing entry for __ex_table The entry for __ex_table was missing, which may make __ex_table become 1- or 2-byte aligned in modules. Add the entry to ensure it gets 32-bit aligned. As per unaligned-memory-access [0] "unaligned memory accesses [...] will not work correctly on certain platforms and will cause performance problems on others", so fix this. Signed-off-by: Helge Deller [mcgrof: added unaligned-memory-access justification] Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/core-api/unaligned-memory-access.rst # [0] Signed-off-by: Luis Chamberlain --- scripts/module.lds.S | 1 + 1 file changed, 1 insertion(+) (limited to 'scripts/module.lds.S') diff --git a/scripts/module.lds.S b/scripts/module.lds.S index 23f9912179ce..69b2423e27ab 100644 --- a/scripts/module.lds.S +++ b/scripts/module.lds.S @@ -29,6 +29,7 @@ SECTIONS { .altinstructions 0 : ALIGN(8) { KEEP(*(.altinstructions)) } __bug_table 0 : ALIGN(8) { KEEP(*(__bug_table)) } __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) } + __ex_table 0 : ALIGN(4) { KEEP(*(__ex_table)) } __patchable_function_entries : { *(__patchable_function_entries) } -- cgit v1.2.3