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module: replace module_layout with module_memory

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module_layout manages different types of memory (text, data, rodata, etc.)
in one allocation, which is problematic for some reasons:

1. It is hard to enable CONFIG_STRICT_MODULE_RWX.
2. It is hard to use huge pages in modules (and not break strict rwx).
3. Many archs uses module_layout for arch-specific data, but it is not
   obvious how these data are used (are they RO, RX, or RW?)

Improve the scenario by replacing 2 (or 3) module_layout per module with
up to 7 module_memory per module:

        MOD_TEXT,
        MOD_DATA,
        MOD_RODATA,
        MOD_RO_AFTER_INIT,
        MOD_INIT_TEXT,
        MOD_INIT_DATA,
        MOD_INIT_RODATA,

and allocating them separately. This adds slightly more entries to
mod_tree (from up to 3 entries per module, to up to 7 entries per
module). However, this at most adds a small constant overhead to
__module_address(), which is expected to be fast.

Various archs use module_layout for different data. These data are put
into different module_memory based on their location in module_layout.
IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT;
data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc.

module_memory simplifies quite some of the module code. For example,
ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a
different allocator for the data. kernel/module/strict_rwx.c is also
much cleaner with module_memory.

Signed-off-by: Song Liu <song@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Song Liu
2023-02-06 16:28:02 -08:00
committed by Luis Chamberlain
parent fe15c26ee2
commit ac3b432839
18 changed files with 437 additions and 477 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
arch/ia64/kernel/module.c
View File

@@ -485,19 +485,19 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
return 0;
}
static inline int
static inline bool
in_init (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size;
return within_module_init(addr, mod);
}
static inline int
static inline bool
in_core (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size;
return within_module_core(addr, mod);
}
static inline int
static inline bool
is_internal (const struct module *mod, uint64_t value)
{
return in_init(mod, value) || in_core(mod, value);
@@ -677,7 +677,8 @@ do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
break;
case RV_BDREL:
val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base);
val -= (uint64_t) (in_init(mod, val) ? mod->mem[MOD_INIT_TEXT].base :
mod->mem[MOD_TEXT].base);
break;
case RV_LTV:
@@ -812,15 +813,18 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind
* addresses have been selected...
*/
uint64_t gp;
if (mod->core_layout.size > MAX_LTOFF)
struct module_memory *mod_mem;
mod_mem = &mod->mem[MOD_DATA];
if (mod_mem->size > MAX_LTOFF)
/*
* This takes advantage of fact that SHF_ARCH_SMALL gets allocated
* at the end of the module.
*/
gp = mod->core_layout.size - MAX_LTOFF / 2;
gp = mod_mem->size - MAX_LTOFF / 2;
else
gp = mod->core_layout.size / 2;
gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8);
gp = mod_mem->size / 2;
gp = (uint64_t) mod_mem->base + ((gp + 7) & -8);
mod->arch.gp = gp;
DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp);
}