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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-12-02 13:00:20 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2021-12-23 22:35:24 +1100
commita3483c3dd18c136785a31406fe27210649fc4fba (patch)
treeb7893804ec9882ee7138335a10bd6d6803998aab /arch/powerpc
parent285672f99327d5b8febdf83cadba61a68abe5d69 (diff)
downloadlinux-a3483c3dd18c136785a31406fe27210649fc4fba.tar.bz2
powerpc/code-patching: Fix unmap_patch_area() error handling
pXd_offset() doesn't return NULL. When the base is NULL, it still adds the offset. Use pXd_none() to check validity instead. It also improves performance by folding out none existing levels as pXd_none() always returns 0 in that case. Such an error is unexpected, use WARN_ON() so that the caller doesn't have to worry about it, and drop the returned value. And now that unmap_patch_area() doesn't return error, we can take into account the error returned by __patch_instruction(). While at it, remove the 'inline' property which is useless. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/299804b117fae35c786c827536c91f25352e279b.1638446239.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/lib/code-patching.c30
1 files changed, 13 insertions, 17 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 380c55d2e41a..740ba0dc5da0 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -94,7 +94,7 @@ static int map_patch_area(void *addr, unsigned long text_poke_addr)
return map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL);
}
-static inline int unmap_patch_area(unsigned long addr)
+static void unmap_patch_area(unsigned long addr)
{
pte_t *ptep;
pmd_t *pmdp;
@@ -103,32 +103,30 @@ static inline int unmap_patch_area(unsigned long addr)
pgd_t *pgdp;
pgdp = pgd_offset_k(addr);
- if (unlikely(!pgdp))
- return -EINVAL;
+ if (WARN_ON(pgd_none(*pgdp)))
+ return;
p4dp = p4d_offset(pgdp, addr);
- if (unlikely(!p4dp))
- return -EINVAL;
+ if (WARN_ON(p4d_none(*p4dp)))
+ return;
pudp = pud_offset(p4dp, addr);
- if (unlikely(!pudp))
- return -EINVAL;
+ if (WARN_ON(pud_none(*pudp)))
+ return;
pmdp = pmd_offset(pudp, addr);
- if (unlikely(!pmdp))
- return -EINVAL;
+ if (WARN_ON(pmd_none(*pmdp)))
+ return;
ptep = pte_offset_kernel(pmdp, addr);
- if (unlikely(!ptep))
- return -EINVAL;
+ if (WARN_ON(pte_none(*ptep)))
+ return;
/*
* In hash, pte_clear flushes the tlb, in radix, we have to
*/
pte_clear(&init_mm, addr, ptep);
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
-
- return 0;
}
static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
@@ -156,11 +154,9 @@ static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
patch_addr = (u32 *)(text_poke_addr + (kaddr & ~PAGE_MASK));
- __patch_instruction(addr, instr, patch_addr);
+ err = __patch_instruction(addr, instr, patch_addr);
- err = unmap_patch_area(text_poke_addr);
- if (err)
- pr_warn("failed to unmap %lx\n", text_poke_addr);
+ unmap_patch_area(text_poke_addr);
out:
local_irq_restore(flags);