[PATCH 4.14 30/41] powerpc/lib/feature-fixups: use raw_patch_instruction()

From: Greg Kroah-Hartman
Date: Thu Oct 18 2018 - 14:01:10 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Christophe Leroy <christophe.leroy@xxxxxx>

commit 8183d99f4a22c2abbc543847a588df3666ef0c0c upstream.

feature fixups need to use patch_instruction() early in the boot,
even before the code is relocated to its final address, requiring
patch_instruction() to use PTRRELOC() in order to address data.

But feature fixups applies on code before it is set to read only,
even for modules. Therefore, feature fixups can use
raw_patch_instruction() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Reported-by: David Gounaris <david.gounaris@xxxxxxxxxxxx>
Tested-by: David Gounaris <david.gounaris@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/include/asm/code-patching.h | 1 +
arch/powerpc/lib/code-patching.c | 4 ++--
arch/powerpc/lib/feature-fixups.c | 8 ++++----
3 files changed, 7 insertions(+), 6 deletions(-)

--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -31,6 +31,7 @@ unsigned int create_cond_branch(const un
unsigned long target, int flags);
int patch_branch(unsigned int *addr, unsigned long target, int flags);
int patch_instruction(unsigned int *addr, unsigned int instr);
+int raw_patch_instruction(unsigned int *addr, unsigned int instr);

int instr_is_relative_branch(unsigned int instr);
int instr_is_relative_link_branch(unsigned int instr);
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -39,7 +39,7 @@ static int __patch_instruction(unsigned
return 0;
}

-static int raw_patch_instruction(unsigned int *addr, unsigned int instr)
+int raw_patch_instruction(unsigned int *addr, unsigned int instr)
{
return __patch_instruction(addr, instr, addr);
}
@@ -156,7 +156,7 @@ static int do_patch_instruction(unsigned
* when text_poke_area is not ready, but we still need
* to allow patching. We just do the plain old patching
*/
- if (!this_cpu_read(*PTRRELOC(&text_poke_area)))
+ if (!this_cpu_read(text_poke_area))
return raw_patch_instruction(addr, instr);

local_irq_save(flags);
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -63,7 +63,7 @@ static int patch_alt_instruction(unsigne
}
}

- patch_instruction(dest, instr);
+ raw_patch_instruction(dest, instr);

return 0;
}
@@ -92,7 +92,7 @@ static int patch_feature_section(unsigne
}

for (; dest < end; dest++)
- patch_instruction(dest, PPC_INST_NOP);
+ raw_patch_instruction(dest, PPC_INST_NOP);

return 0;
}
@@ -292,7 +292,7 @@ void do_lwsync_fixups(unsigned long valu

for (; start < end; start++) {
dest = (void *)start + *start;
- patch_instruction(dest, PPC_INST_LWSYNC);
+ raw_patch_instruction(dest, PPC_INST_LWSYNC);
}
}

@@ -310,7 +310,7 @@ static void do_final_fixups(void)
length = (__end_interrupts - _stext) / sizeof(int);

while (length--) {
- patch_instruction(dest, *src);
+ raw_patch_instruction(dest, *src);
src++;
dest++;
}