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author | Mark Rutland <mark.rutland@arm.com> | 2023-01-23 13:46:01 +0000 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-01-24 11:49:43 +0000 |
commit | e4ecbe83fd1a5428d5458de04a3404f1b5444429 (patch) | |
tree | 0e7fafdcb46e5fe7277be82d46bfd55809662652 /arch/arm64 | |
parent | 2bbbb4015aa1af62f8002de86de019786ecf63a7 (diff) | |
download | linux-stable-e4ecbe83fd1a5428d5458de04a3404f1b5444429.tar.gz linux-stable-e4ecbe83fd1a5428d5458de04a3404f1b5444429.tar.bz2 linux-stable-e4ecbe83fd1a5428d5458de04a3404f1b5444429.zip |
arm64: patching: Add aarch64_insn_write_literal_u64()
In subsequent patches we'll need to atomically write to a
naturally-aligned 64-bit literal embedded within the kernel text.
Add a helper for this. For consistency with other text patching code we
use copy_to_kernel_nofault(), which is atomic for naturally-aligned
accesses up to 64-bits.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230123134603.1064407-7-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/include/asm/patching.h | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/patching.c | 17 |
2 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h index 6bf5adc56295..68908b82b168 100644 --- a/arch/arm64/include/asm/patching.h +++ b/arch/arm64/include/asm/patching.h @@ -7,6 +7,8 @@ int aarch64_insn_read(void *addr, u32 *insnp); int aarch64_insn_write(void *addr, u32 insn); +int aarch64_insn_write_literal_u64(void *addr, u64 val); + int aarch64_insn_patch_text_nosync(void *addr, u32 insn); int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c index 33e0fabc0b79..b4835f6d594b 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -88,6 +88,23 @@ int __kprobes aarch64_insn_write(void *addr, u32 insn) return __aarch64_insn_write(addr, cpu_to_le32(insn)); } +noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val) +{ + u64 *waddr; + unsigned long flags; + int ret; + + raw_spin_lock_irqsave(&patch_lock, flags); + waddr = patch_map(addr, FIX_TEXT_POKE0); + + ret = copy_to_kernel_nofault(waddr, &val, sizeof(val)); + + patch_unmap(FIX_TEXT_POKE0); + raw_spin_unlock_irqrestore(&patch_lock, flags); + + return ret; +} + int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) { u32 *tp = addr; |