52dbd67dff
[Changes from V1: - Avoid conflict by rebasing with latest master.] Some BPF tests use loop unrolling compiler pragmas that are clang specific and not supported by GCC. These pragmas, along with their GCC equivalences are: #pragma clang loop unroll_count(N) #pragma GCC unroll N #pragma clang loop unroll(full) #pragma GCC unroll 65534 #pragma clang loop unroll(disable) #pragma GCC unroll 1 #pragma unroll [aka #pragma clang loop unroll(enable)] There is no GCC equivalence to this pragma. It enables unrolling on loops that the compiler would not ordinarily unroll even with -O2|-funroll-loops, but it is not equivalent to full unrolling either. This patch adds a new header progs/bpf_compiler.h that defines the following macros, which correspond to each pair of compiler-specific pragmas above: __pragma_loop_unroll_count(N) __pragma_loop_unroll_full __pragma_loop_no_unroll __pragma_loop_unroll The selftests using loop unrolling pragmas are then changed to include the header and use these macros in place of the explicit pragmas. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240208203612.29611-1-jose.marchesi@oracle.com
76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// Copyright (c) 2019 Facebook
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include <linux/stddef.h>
|
|
#include <linux/bpf.h>
|
|
|
|
#include <bpf/bpf_helpers.h>
|
|
|
|
#include "bpf_compiler.h"
|
|
|
|
/* Max supported length of a string with unsigned long in base 10 (pow2 - 1). */
|
|
#define MAX_ULONG_STR_LEN 0xF
|
|
|
|
/* Max supported length of sysctl value string (pow2). */
|
|
#define MAX_VALUE_STR_LEN 0x40
|
|
|
|
#ifndef ARRAY_SIZE
|
|
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
|
|
#endif
|
|
|
|
const char tcp_mem_name[] = "net/ipv4/tcp_mem";
|
|
static __always_inline int is_tcp_mem(struct bpf_sysctl *ctx)
|
|
{
|
|
unsigned char i;
|
|
char name[sizeof(tcp_mem_name)];
|
|
int ret;
|
|
|
|
memset(name, 0, sizeof(name));
|
|
ret = bpf_sysctl_get_name(ctx, name, sizeof(name), 0);
|
|
if (ret < 0 || ret != sizeof(tcp_mem_name) - 1)
|
|
return 0;
|
|
|
|
__pragma_loop_unroll_full
|
|
for (i = 0; i < sizeof(tcp_mem_name); ++i)
|
|
if (name[i] != tcp_mem_name[i])
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
SEC("cgroup/sysctl")
|
|
int sysctl_tcp_mem(struct bpf_sysctl *ctx)
|
|
{
|
|
unsigned long tcp_mem[3] = {0, 0, 0};
|
|
char value[MAX_VALUE_STR_LEN];
|
|
unsigned char i, off = 0;
|
|
volatile int ret;
|
|
|
|
if (ctx->write)
|
|
return 0;
|
|
|
|
if (!is_tcp_mem(ctx))
|
|
return 0;
|
|
|
|
ret = bpf_sysctl_get_current_value(ctx, value, MAX_VALUE_STR_LEN);
|
|
if (ret < 0 || ret >= MAX_VALUE_STR_LEN)
|
|
return 0;
|
|
|
|
__pragma_loop_unroll_full
|
|
for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) {
|
|
ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0,
|
|
tcp_mem + i);
|
|
if (ret <= 0 || ret > MAX_ULONG_STR_LEN)
|
|
return 0;
|
|
off += ret & MAX_ULONG_STR_LEN;
|
|
}
|
|
|
|
|
|
return tcp_mem[0] < tcp_mem[1] && tcp_mem[1] < tcp_mem[2];
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|