diff mbox series

[bpf-next,v4,2/6] x86/alternative: support execmem_alloc() and execmem_free()

Message ID 20221117202322.944661-3-song@kernel.org (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series execmem_alloc for BPF programs | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-VM_Test-10 pending Logs for test_maps on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 pending Logs for test_maps on x86_64 with llvm-16
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bpf/vmtest-bpf-next-VM_Test-22 pending Logs for test_progs_no_alu32 on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-25 pending Logs for test_progs_no_alu32_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-27 pending Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 pending Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 pending Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-30 pending Logs for test_progs_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-32 pending Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-33 pending Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-34 pending Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-35 pending Logs for test_verifier on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-37 pending Logs for test_verifier on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_maps on x86_64 with gcc
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bpf/vmtest-bpf-next-VM_Test-36 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-31 success Logs for test_progs_parallel on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_maps on s390x with gcc
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 7 maintainers not CCed: tglx@linutronix.de bp@alien8.de mingo@redhat.com dave.hansen@linux.intel.com jpoimboe@kernel.org namit@vmware.com hpa@zytor.com
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch warning CHECK: Comparison to NULL could be written "!text_poke_copy"
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ${{ matrix.test }} on ${{ matrix.arch }} with ${{ matrix.toolchain }}
bpf/vmtest-bpf-next-VM_Test-2 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-5 fail Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-7 success Logs for build for x86_64 with llvm-16
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bpf/vmtest-bpf-next-VM_Test-9 success Logs for set-matrix
bpf/vmtest-bpf-next-PR success PR summary

Commit Message

Song Liu Nov. 17, 2022, 8:23 p.m. UTC 
Implement arch_fill_execmem() and arch_invalidate_execmem() to support
execmem_alloc.

arch_fill_execmem() copies dynamic kernel text (such as BPF programs) to
RO+X memory region allocated by execmem_alloc().

arch_invalidate_execmem() fills memory with 0xcc after it is released by
execmem_free().

Signed-off-by: Song Liu <song@kernel.org>
---
 arch/x86/kernel/alternative.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5cadcea035e0..e38829f19a81 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1270,6 +1270,18 @@  void *text_poke_copy(void *addr, const void *opcode, size_t len)
 	return addr;
 }
 
+void *arch_fill_execmem(void *dst, void *src, size_t len)
+{
+	if (text_poke_copy(dst, src, len) == NULL)
+		return ERR_PTR(-EINVAL);
+	return dst;
+}
+
+int arch_invalidate_execmem(void *ptr, size_t len)
+{
+	return IS_ERR_OR_NULL(text_poke_set(ptr, 0xcc, len));
+}
+
 /**
  * text_poke_set - memset into (an unused part of) RX memory
  * @addr: address to modify