Patchwork [1/2] powerpc: make kernel module helper endian-safe.

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Submitter Eugene Surovegin
Date Sept. 20, 2013, 6:42 p.m.
Message ID <1379702541-28372-1-git-send-email-ebs@ebshome.net>
Download mbox | patch
Permalink /patch/276600/
State Accepted
Commit fed8393ef9f779e51c3e0c844e549e0bbc8d6dd4
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Eugene Surovegin - Sept. 20, 2013, 6:42 p.m.
Signed-off-by: Eugene Surovegin <surovegin@google.com>
---
 arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
David Laight - Sept. 23, 2013, 8:34 a.m.
> --- a/arch/powerpc/kernel/module_64.c
> +++ b/arch/powerpc/kernel/module_64.c
> @@ -62,6 +62,16 @@ struct ppc64_stub_entry
>     r2) into the stub. */
>  static struct ppc64_stub_entry ppc64_stub =
>  { .jump = {
> +#ifdef __LITTLE_ENDIAN__
> +	0x00, 0x00, 0x82, 0x3d, /* addis   r12,r2, <high> */
> +	0x00, 0x00, 0x8c, 0x39, /* addi    r12,r12, <low> */
> +	/* Save current r2 value in magic place on the stack. */
> +	0x28, 0x00, 0x41, 0xf8, /* std     r2,40(r1) */
> +	0x20, 0x00, 0x6c, 0xe9, /* ld      r11,32(r12) */
> +	0x28, 0x00, 0x4c, 0xe8, /* ld      r2,40(r12) */
> +	0xa6, 0x03, 0x69, 0x7d, /* mtctr   r11 */
> +	0x20, 0x04, 0x80, 0x4e  /* bctr */
> +#else
>  	0x3d, 0x82, 0x00, 0x00, /* addis   r12,r2, <high> */
>  	0x39, 0x8c, 0x00, 0x00, /* addi    r12,r12, <low> */
>  	/* Save current r2 value in magic place on the stack. */
> @@ -70,6 +80,7 @@ static struct ppc64_stub_entry ppc64_stub =
>  	0xe8, 0x4c, 0x00, 0x28, /* ld      r2,40(r12) */
>  	0x7d, 0x69, 0x03, 0xa6, /* mtctr   r11 */
>  	0x4e, 0x80, 0x04, 0x20  /* bctr */
> +#endif

Seems to me that should be a list of 32bit constants.

	David

Patch

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 6ee59a0..a102f44 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -62,6 +62,16 @@  struct ppc64_stub_entry
    r2) into the stub. */
 static struct ppc64_stub_entry ppc64_stub =
 { .jump = {
+#ifdef __LITTLE_ENDIAN__
+	0x00, 0x00, 0x82, 0x3d, /* addis   r12,r2, <high> */
+	0x00, 0x00, 0x8c, 0x39, /* addi    r12,r12, <low> */
+	/* Save current r2 value in magic place on the stack. */
+	0x28, 0x00, 0x41, 0xf8, /* std     r2,40(r1) */
+	0x20, 0x00, 0x6c, 0xe9, /* ld      r11,32(r12) */
+	0x28, 0x00, 0x4c, 0xe8, /* ld      r2,40(r12) */
+	0xa6, 0x03, 0x69, 0x7d, /* mtctr   r11 */
+	0x20, 0x04, 0x80, 0x4e  /* bctr */
+#else
 	0x3d, 0x82, 0x00, 0x00, /* addis   r12,r2, <high> */
 	0x39, 0x8c, 0x00, 0x00, /* addi    r12,r12, <low> */
 	/* Save current r2 value in magic place on the stack. */
@@ -70,6 +80,7 @@  static struct ppc64_stub_entry ppc64_stub =
 	0xe8, 0x4c, 0x00, 0x28, /* ld      r2,40(r12) */
 	0x7d, 0x69, 0x03, 0xa6, /* mtctr   r11 */
 	0x4e, 0x80, 0x04, 0x20  /* bctr */
+#endif
 } };
 
 /* Count how many different 24-bit relocations (different symbol,
@@ -269,8 +280,13 @@  static inline int create_stub(Elf64_Shdr *sechdrs,
 
 	*entry = ppc64_stub;
 
+#ifdef __LITTLE_ENDIAN__
+	loc1 = (Elf64_Half *)&entry->jump[0];
+	loc2 = (Elf64_Half *)&entry->jump[4];
+#else
 	loc1 = (Elf64_Half *)&entry->jump[2];
 	loc2 = (Elf64_Half *)&entry->jump[6];
+#endif
 
 	/* Stub uses address relative to r2. */
 	reladdr = (unsigned long)entry - my_r2(sechdrs, me);