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powerpc/lib/code-patching: refactor patch_instruction()

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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>
This commit is contained in:
Christophe Leroy 2017-11-24 08:31:07 +01:00 committed by Michael Ellerman
parent 4ec591e51a
commit 8cf4c05712
1 changed files with 15 additions and 15 deletions
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30
arch/powerpc/lib/code-patching.c
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@ -23,19 +23,26 @@
#include <asm/code-patching.h> #include <asm/code-patching.h>
#include <asm/setup.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; int err;
__put_user_size(instr, addr, 4, err); __put_user_size(instr, patch_addr, 4, err);
if (err) if (err)
return 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; return 0;
} }
static int raw_patch_instruction(unsigned int *addr, unsigned int instr)
{
return __patch_instruction(addr, instr, addr);
}
#ifdef CONFIG_STRICT_KERNEL_RWX #ifdef CONFIG_STRICT_KERNEL_RWX
static DEFINE_PER_CPU(struct vm_struct *, text_poke_area); static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
@ -138,7 +145,7 @@ static inline int unmap_patch_area(unsigned long addr)
int patch_instruction(unsigned int *addr, unsigned int instr) int patch_instruction(unsigned int *addr, unsigned int instr)
{ {
int err; int err;
unsigned int *dest = NULL; unsigned int *patch_addr = NULL;
unsigned long flags; unsigned long flags;
unsigned long text_poke_addr; unsigned long text_poke_addr;
unsigned long kaddr = (unsigned long)addr; unsigned long kaddr = (unsigned long)addr;
@ -149,7 +156,7 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
* to allow patching. We just do the plain old patching * to allow patching. We just do the plain old patching
*/ */
if (!this_cpu_read(*PTRRELOC(&text_poke_area))) if (!this_cpu_read(*PTRRELOC(&text_poke_area)))
return __patch_instruction(addr, instr); return raw_patch_instruction(addr, instr);
local_irq_save(flags); local_irq_save(flags);
@ -159,17 +166,10 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
goto out; goto out;
} }
dest = (unsigned int *)(text_poke_addr) + patch_addr = (unsigned int *)(text_poke_addr) +
((kaddr & ~PAGE_MASK) / sizeof(unsigned int)); ((kaddr & ~PAGE_MASK) / sizeof(unsigned int));
/* __patch_instruction(addr, instr, patch_addr);
* 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));
err = unmap_patch_area(text_poke_addr); err = unmap_patch_area(text_poke_addr);
if (err) if (err)
@ -184,7 +184,7 @@ out:
int patch_instruction(unsigned int *addr, unsigned int instr) 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 */ #endif /* CONFIG_STRICT_KERNEL_RWX */