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powerpc: module_[32|64].c: replace swap function with built-in one
authorAndrey Abramov <st5pub@yandex.ru>
Tue, 2 Apr 2019 20:47:22 +0000 (23:47 +0300)
committerMichael Ellerman <mpe@ellerman.id.au>
Mon, 11 May 2020 13:15:14 +0000 (23:15 +1000)
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: Andrey Abramov <st5pub@yandex.ru>
Reviewed-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/994931554238042@iva8-b333b7f98ab0.qloud-c.yandex.net
arch/powerpc/kernel/module_32.c
arch/powerpc/kernel/module_64.c

index d7134c6..c27b868 100644 (file)
@@ -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,
index 007606a..f808159 100644 (file)
@@ -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