From d2fae548039987e0c64957ede44822305fdafb66 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 18 Mar 2014 20:12:44 +1030 Subject: [PATCH] powerpc: modules: change r2 save/restore offset for ELFv2 ABI. ELFv2 uses a different stack offset (24 vs 40) to save r2. Signed-off-by: Rusty Russell --- arch/powerpc/kernel/module_64.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 05b27a5efc7e..8bfcf1b8b6d4 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -41,6 +41,12 @@ #define DEBUGP(fmt , ...) #endif +#if defined(_CALL_ELF) && _CALL_ELF == 2 +#define R2_STACK_OFFSET 24 +#else +#define R2_STACK_OFFSET 40 +#endif + /* Like PPC32, we need little trampolines to do > 24-bit jumps (into the kernel itself). But on PPC64, these need to be used for every jump, actually, to reset r2 (TOC+0x8000). */ @@ -61,14 +67,14 @@ struct ppc64_stub_entry r2) into the stub. */ static struct ppc64_stub_entry ppc64_stub = { .jump = { - 0x3d820000, /* addis r12,r2, */ - 0x398c0000, /* addi r12,r12, */ + 0x3d820000, /* addis r12,r2, */ + 0x398c0000, /* addi r12,r12, */ /* Save current r2 value in magic place on the stack. */ - 0xf8410028, /* std r2,40(r1) */ - 0xe96c0020, /* ld r11,32(r12) */ - 0xe84c0028, /* ld r2,40(r12) */ - 0x7d6903a6, /* mtctr r11 */ - 0x4e800420 /* bctr */ + 0xf8410000|R2_STACK_OFFSET, /* std r2,R2_STACK_OFFSET(r1) */ + 0xe96c0020, /* ld r11,32(r12) */ + 0xe84c0028, /* ld r2,40(r12) */ + 0x7d6903a6, /* mtctr r11 */ + 0x4e800420 /* bctr */ } }; /* Count how many different 24-bit relocations (different symbol, @@ -338,7 +344,8 @@ static int restore_r2(u32 *instruction, struct module *me) me->name, *instruction); return 0; } - *instruction = 0xe8410028; /* ld r2,40(r1) */ + /* ld r2,R2_STACK_OFFSET(r1) */ + *instruction = 0xe8410000 | R2_STACK_OFFSET; return 1; } -- 2.39.5