diff mbox series

[RESEND,bpf-next,v8,1/3] bpf, x86: save/restore regs with BPF_DW size

Message ID 20230710104834.947884-2-imagedong@tencent.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf, x86: allow function arguments up to 12 for TRACING | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 7 maintainers not CCed: tglx@linutronix.de hpa@zytor.com mingo@redhat.com netdev@vger.kernel.org dave.hansen@linux.intel.com davem@davemloft.net bp@alien8.de
netdev/build_clang fail Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 10 this patch: 10
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 63 lines checked
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 ShellCheck
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-6 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-18 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-22 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for veristat
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 fail Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-PR fail PR summary
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on s390x with gcc

Commit Message

Menglong Dong July 10, 2023, 10:48 a.m. UTC 
From: Menglong Dong <imagedong@tencent.com>

As we already reserve 8 byte in the stack for each reg, it is ok to
store/restore the regs in BPF_DW size. This will make the code in
save_regs()/restore_regs() simpler.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Acked-by: Yonghong Song <yhs@fb.com>
---
v6:
- adjust the commit log
---
 arch/x86/net/bpf_jit_comp.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 438adb695daa..fcbd3b7123a4 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1860,57 +1860,34 @@  st:			if (is_imm8(insn->off))
 static void save_regs(const struct btf_func_model *m, u8 **prog, int nr_regs,
 		      int stack_size)
 {
-	int i, j, arg_size;
-	bool next_same_struct = false;
+	int i;
 
 	/* Store function arguments to stack.
 	 * For a function that accepts two pointers the sequence will be:
 	 * mov QWORD PTR [rbp-0x10],rdi
 	 * mov QWORD PTR [rbp-0x8],rsi
 	 */
-	for (i = 0, j = 0; i < min(nr_regs, 6); i++) {
-		/* The arg_size is at most 16 bytes, enforced by the verifier. */
-		arg_size = m->arg_size[j];
-		if (arg_size > 8) {
-			arg_size = 8;
-			next_same_struct = !next_same_struct;
-		}
-
-		emit_stx(prog, bytes_to_bpf_size(arg_size),
-			 BPF_REG_FP,
+	for (i = 0; i < min(nr_regs, 6); i++)
+		emit_stx(prog, BPF_DW, BPF_REG_FP,
 			 i == 5 ? X86_REG_R9 : BPF_REG_1 + i,
 			 -(stack_size - i * 8));
-
-		j = next_same_struct ? j : j + 1;
-	}
 }
 
 static void restore_regs(const struct btf_func_model *m, u8 **prog, int nr_regs,
 			 int stack_size)
 {
-	int i, j, arg_size;
-	bool next_same_struct = false;
+	int i;
 
 	/* Restore function arguments from stack.
 	 * For a function that accepts two pointers the sequence will be:
 	 * EMIT4(0x48, 0x8B, 0x7D, 0xF0); mov rdi,QWORD PTR [rbp-0x10]
 	 * EMIT4(0x48, 0x8B, 0x75, 0xF8); mov rsi,QWORD PTR [rbp-0x8]
 	 */
-	for (i = 0, j = 0; i < min(nr_regs, 6); i++) {
-		/* The arg_size is at most 16 bytes, enforced by the verifier. */
-		arg_size = m->arg_size[j];
-		if (arg_size > 8) {
-			arg_size = 8;
-			next_same_struct = !next_same_struct;
-		}
-
-		emit_ldx(prog, bytes_to_bpf_size(arg_size),
+	for (i = 0; i < min(nr_regs, 6); i++)
+		emit_ldx(prog, BPF_DW,
 			 i == 5 ? X86_REG_R9 : BPF_REG_1 + i,
 			 BPF_REG_FP,
 			 -(stack_size - i * 8));
-
-		j = next_same_struct ? j : j + 1;
-	}
 }
 
 static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog,