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author | Song Liu <song@kernel.org> | 2023-02-06 16:28:02 -0800 |
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committer | Luis Chamberlain <mcgrof@kernel.org> | 2023-03-09 12:55:15 -0800 |
commit | ac3b43283923440900b4f36ca5f9f0b1ca43b70e (patch) | |
tree | 32430a7fa302c652cd2fc675dc0435e0792b9710 /arch/arc | |
parent | fe15c26ee26efa11741a7b632e9f23b01aca4cc6 (diff) | |
download | lwn-ac3b43283923440900b4f36ca5f9f0b1ca43b70e.tar.gz lwn-ac3b43283923440900b4f36ca5f9f0b1ca43b70e.zip |
module: replace module_layout with module_memory
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>
Diffstat (limited to 'arch/arc')
-rw-r--r-- | arch/arc/kernel/unwind.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c index 200270a94558..9270d0a713c3 100644 --- a/arch/arc/kernel/unwind.c +++ b/arch/arc/kernel/unwind.c @@ -369,6 +369,8 @@ void *unwind_add_table(struct module *module, const void *table_start, unsigned long table_size) { struct unwind_table *table; + struct module_memory *core_text; + struct module_memory *init_text; if (table_size <= 0) return NULL; @@ -377,11 +379,11 @@ void *unwind_add_table(struct module *module, const void *table_start, if (!table) return NULL; - init_unwind_table(table, module->name, - module->core_layout.base, module->core_layout.size, - module->init_layout.base, module->init_layout.size, - table_start, table_size, - NULL, 0); + core_text = &module->mem[MOD_TEXT]; + init_text = &module->mem[MOD_INIT_TEXT]; + + init_unwind_table(table, module->name, core_text->base, core_text->size, + init_text->base, init_text->size, table_start, table_size, NULL, 0); init_unwind_hdr(table, unw_hdr_alloc); |