Commit bac7ca7b authored by Andrey Abramov's avatar Andrey Abramov Committed by Michael Ellerman
Browse files

powerpc: module_[32|64].c: replace swap function with built-in one 



Replace relaswap with built-in one, because relaswap
does a simple byte to byte swap.

Since Spectre mitigations have made indirect function calls more
expensive, and the default simple byte copies swap is implemented
without them, an "optimized" custom swap function is now
a waste of time as well as code.

Signed-off-by: default avatarAndrey Abramov <st5pub@yandex.ru>
Reviewed-by: default avatarGeorge Spelvin <lkml@sdf.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/994931554238042@iva8-b333b7f98ab0.qloud-c.yandex.net
parent 2f62870c

arch/powerpc/kernel/module_32.c

+1 −16
Original line number Diff line number Diff line
@@ -67,21 +67,6 @@ static int relacmp(const void *_x, const void *_y) 
		return 0;

}



static void relaswap(void *_x, void *_y, int size)

{

	uint32_t *x, *y, tmp;

	int i;



	y = (uint32_t *)_x;

	x = (uint32_t *)_y;



	for (i = 0; i < sizeof(Elf32_Rela) / sizeof(uint32_t); i++) {

		tmp = x[i];

		x[i] = y[i];

		y[i] = tmp;

	}

}



/* Get the potential trampolines size required of the init and

   non-init sections */

static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
@@ -118,7 +103,7 @@ static unsigned long get_plt_size(const Elf32_Ehdr *hdr, 
			 */

			sort((void *)hdr + sechdrs[i].sh_offset,

			     sechdrs[i].sh_size / sizeof(Elf32_Rela),

			     sizeof(Elf32_Rela), relacmp, relaswap);

			     sizeof(Elf32_Rela), relacmp, NULL);



			ret += count_relocs((void *)hdr

					     + sechdrs[i].sh_offset,

arch/powerpc/kernel/module_64.c

+1 −16
Original line number Diff line number Diff line
@@ -226,21 +226,6 @@ static int relacmp(const void *_x, const void *_y) 
		return 0;

}



static void relaswap(void *_x, void *_y, int size)

{

	uint64_t *x, *y, tmp;

	int i;



	y = (uint64_t *)_x;

	x = (uint64_t *)_y;



	for (i = 0; i < sizeof(Elf64_Rela) / sizeof(uint64_t); i++) {

		tmp = x[i];

		x[i] = y[i];

		y[i] = tmp;

	}

}



/* Get size of potential trampolines required. */

static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,

				    const Elf64_Shdr *sechdrs)
@@ -264,7 +249,7 @@ static unsigned long get_stubs_size(const Elf64_Ehdr *hdr, 
			 */

			sort((void *)sechdrs[i].sh_addr,

			     sechdrs[i].sh_size / sizeof(Elf64_Rela),

			     sizeof(Elf64_Rela), relacmp, relaswap);

			     sizeof(Elf64_Rela), relacmp, NULL);



			relocs += count_relocs((void *)sechdrs[i].sh_addr,

					       sechdrs[i].sh_size