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Subject[PATCH 4.14 33/45] powerpc/lib/code-patching: refactor patch_instruction()
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

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

From: Christophe Leroy <christophe.leroy@c-s.fr>

commit 8cf4c05712f04a405f0dacebcca8f042b391694a upstream.

patch_instruction() uses almost the same sequence as
__patch_instruction()

This patch refactor it so that patch_instruction() uses
__patch_instruction() instead of duplicating code.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/powerpc/lib/code-patching.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)

--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -23,19 +23,26 @@
#include <asm/code-patching.h>
#include <asm/setup.h>

-static int __patch_instruction(unsigned int *addr, unsigned int instr)
+static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
+ unsigned int *patch_addr)
{
int err;

- __put_user_size(instr, addr, 4, err);
+ __put_user_size(instr, patch_addr, 4, err);
if (err)
return err;

- asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" :: "r" (addr));
+ asm ("dcbst 0, %0; sync; icbi 0,%1; sync; isync" :: "r" (patch_addr),
+ "r" (exec_addr));

return 0;
}

+static int raw_patch_instruction(unsigned int *addr, unsigned int instr)
+{
+ return __patch_instruction(addr, instr, addr);
+}
+
#ifdef CONFIG_STRICT_KERNEL_RWX
static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);

@@ -138,7 +145,7 @@ static inline int unmap_patch_area(unsig
int patch_instruction(unsigned int *addr, unsigned int instr)
{
int err;
- unsigned int *dest = NULL;
+ unsigned int *patch_addr = NULL;
unsigned long flags;
unsigned long text_poke_addr;
unsigned long kaddr = (unsigned long)addr;
@@ -149,7 +156,7 @@ int patch_instruction(unsigned int *addr
* to allow patching. We just do the plain old patching
*/
if (!this_cpu_read(*PTRRELOC(&text_poke_area)))
- return __patch_instruction(addr, instr);
+ return raw_patch_instruction(addr, instr);

local_irq_save(flags);

@@ -159,17 +166,10 @@ int patch_instruction(unsigned int *addr
goto out;
}

- dest = (unsigned int *)(text_poke_addr) +
+ patch_addr = (unsigned int *)(text_poke_addr) +
((kaddr & ~PAGE_MASK) / sizeof(unsigned int));

- /*
- * We use __put_user_size so that we can handle faults while
- * writing to dest and return err to handle faults gracefully
- */
- __put_user_size(instr, dest, 4, err);
- if (!err)
- asm ("dcbst 0, %0; sync; icbi 0,%0; icbi 0,%1; sync; isync"
- ::"r" (dest), "r"(addr));
+ __patch_instruction(addr, instr, patch_addr);

err = unmap_patch_area(text_poke_addr);
if (err)
@@ -184,7 +184,7 @@ out:

int patch_instruction(unsigned int *addr, unsigned int instr)
{
- return __patch_instruction(addr, instr);
+ return raw_patch_instruction(addr, instr);
}

#endif /* CONFIG_STRICT_KERNEL_RWX */

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