Re: [PATCH] parisc: fix module loading failure of large kernel modules(take 4)

From: Helge Deller
Date: Wed Dec 31 2008 - 06:31:32 EST


[PATCH 1/2] module.c: fix module loading failure of large kernel modules

When creating the final layout of a kernel module in memory, allow the
module loader to reserve some additional memory in front of a given section.
This is currently only needed for the parisc port which needs to put the
stub entries there to fulfill the 17/22bit PCREL relocations with large
kernel modules like xfs.

Differences of this patch to previous versions:
- added weak funtion arch_module_section_size()
- no kernel config options needed
- no overloading of sh_entsize

Signed-off-by: Helge Deller <deller@xxxxxx>

diffstat:
include/linux/moduleloader.h | 4 ++++
kernel/module.c | 16 +++++++++++++---
2 files changed, 17 insertions(+), 3 deletions(-)


diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index eb10339..f2b1b62 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -13,6 +13,10 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
char *secstrings,
struct module *mod);

+/* Additional bytes needed by arch in front of individual sections */
+unsigned int arch_module_section_size(struct module *mod,
+ unsigned int section);
+
/* Allocator used for allocating struct module, core sections and init
sections. Returns NULL on failure. */
void *module_alloc(unsigned long size);
diff --git a/kernel/module.c b/kernel/module.c
index 1f4cc00..5b91b17 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1578,11 +1578,21 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
return ret;
}

+/* Additional bytes needed by arch in front of individual sections */
+unsigned int __attribute__ ((weak)) arch_module_section_size(
+ struct module *mod, unsigned int section)
+{
+ /* default implementation just returns zero */
+ return 0;
+}
+
/* Update size with this section: return offset. */
-static long get_offset(unsigned int *size, Elf_Shdr *sechdr)
+static long get_offset(struct module *mod, unsigned int *size,
+ Elf_Shdr *sechdr, unsigned int section)
{
long ret;

+ *size += arch_module_section_size(mod, section);
ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
*size = ret + sechdr->sh_size;
return ret;
@@ -1622,7 +1632,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) == 0)
continue;
- s->sh_entsize = get_offset(&mod->core_size, s);
+ s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
if (m == 0)
@@ -1640,7 +1650,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) != 0)
continue;
- s->sh_entsize = (get_offset(&mod->init_size, s)
+ s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
| INIT_OFFSET_MASK);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
--
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