From: Benjamin Gray <bgray@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Naveen N Rao <naveen@kernel.org>, Benjamin Gray <bgray@linux.ibm.com>
Subject: [PATCH v3 3/5] powerpc/64: Convert patch_instruction() to patch_u32()
Date: Mon, 25 Mar 2024 16:53:00 +1100 [thread overview]
Message-ID: <20240325055302.876434-4-bgray@linux.ibm.com> (raw)
In-Reply-To: <20240325055302.876434-1-bgray@linux.ibm.com>
This use of patch_instruction() is working on 32 bit data, and can fail
if the data looks like a prefixed instruction and the extra write
crosses a page boundary. Use patch_u32() to fix the write size.
Fixes: 8734b41b3efe ("powerpc/module_64: Fix livepatching for RO modules")
Link: https://lore.kernel.org/all/20230203004649.1f59dbd4@yea/
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
---
v2: * Added the fixes tag, it seems appropriate even if the subject does
mention a more robust solution being required.
patch_u64() should be more efficient, but judging from the bug report
it doesn't seem like the data is doubleword aligned.
---
arch/powerpc/kernel/module_64.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 7112adc597a8..e9bab599d0c2 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -651,12 +651,11 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
// func_desc_t is 8 bytes if ABIv2, else 16 bytes
desc = func_desc(addr);
for (i = 0; i < sizeof(func_desc_t) / sizeof(u32); i++) {
- if (patch_instruction(((u32 *)&entry->funcdata) + i,
- ppc_inst(((u32 *)(&desc))[i])))
+ if (patch_u32(((u32 *)&entry->funcdata) + i, ((u32 *)&desc)[i]))
return 0;
}
- if (patch_instruction(&entry->magic, ppc_inst(STUB_MAGIC)))
+ if (patch_u32(&entry->magic, STUB_MAGIC))
return 0;
return 1;
--
2.44.0
next prev parent reply other threads:[~2024-03-25 5:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-25 5:52 [PATCH v3 0/5] Add generic data patching functions Benjamin Gray
2024-03-25 5:52 ` [PATCH v3 1/5] powerpc/code-patching: Add generic memory patching Benjamin Gray
2024-03-25 5:52 ` [PATCH v3 2/5] powerpc/code-patching: Add data patch alignment check Benjamin Gray
2024-03-25 5:53 ` Benjamin Gray [this message]
2024-04-23 9:39 ` [PATCH v3 3/5] powerpc/64: Convert patch_instruction() to patch_u32() Naveen N Rao
2024-05-14 2:59 ` Benjamin Gray
2024-05-14 4:39 ` Christophe Leroy
2024-05-14 10:42 ` Naveen N Rao
2024-03-25 5:53 ` [PATCH v3 4/5] powerpc/32: Convert patch_instruction() to patch_uint() Benjamin Gray
2024-03-25 5:53 ` [PATCH v3 5/5] powerpc/code-patching: Add boot selftest for data patching Benjamin Gray
2024-04-23 9:25 ` Naveen N Rao
2024-04-23 9:40 ` [PATCH v3 0/5] Add generic data patching functions Naveen N Rao
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