This series is preparing to add the -Wsign-compare C compilation flag to the Makefile for bpf selftests as requested by a TODO to help avoid implicit type conversions and have predictable behavior.
Changelog:
Changes from v2:
-Split up the patch into a patch series as suggested by vivek
-Include only changes to variable types with no casting by my mentor david
-Removed the -Wsign-compare in Makefile to avoid compilation errors until adding casting for rest of comparisons.
Link:https://lore.kernel.org/bpf/20250924195731.6374-1-mehdi.benhadjkhelifa@gmail...
Changes from v1:
- Fix CI failed builds where it failed due to do missing .c and .h files in my patch for working in mainline.
Link:https://lore.kernel.org/bpf/20250924162408.815137-1-mehdi.benhadjkhelifa@gma...
Mehdi Ben Hadj Khelifa (3): selftests/bpf: Prepare to add -Wsign-compare for bpf tests selftests/bpf: Prepare to add -Wsign-compare for bpf tests selftests/bpf: Prepare to add -Wsign-compare for bpf tests
tools/testing/selftests/bpf/progs/test_global_func11.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func12.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func13.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func9.c | 2 +- tools/testing/selftests/bpf/progs/test_map_init.c | 2 +- tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c | 2 +- .../selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_skb_ctx.c | 2 +- tools/testing/selftests/bpf/progs/test_snprintf.c | 2 +- tools/testing/selftests/bpf/progs/test_sockmap_strp.c | 2 +- tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 18 files changed, 22 insertions(+), 21 deletions(-)
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com --- tools/testing/selftests/bpf/progs/test_global_func11.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func12.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func13.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func9.c | 2 +- tools/testing/selftests/bpf/progs/test_map_init.c | 2 +- tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c | 2 +- 6 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_global_func11.c b/tools/testing/selftests/bpf/progs/test_global_func11.c index 283e036dc401..2ad72bf0e07b 100644 --- a/tools/testing/selftests/bpf/progs/test_global_func11.c +++ b/tools/testing/selftests/bpf/progs/test_global_func11.c @@ -5,7 +5,7 @@ #include "bpf_misc.h"
struct S { - int x; + __u32 x; };
__noinline int foo(const struct S *s) diff --git a/tools/testing/selftests/bpf/progs/test_global_func12.c b/tools/testing/selftests/bpf/progs/test_global_func12.c index 6e03d42519a6..53eab8ec6772 100644 --- a/tools/testing/selftests/bpf/progs/test_global_func12.c +++ b/tools/testing/selftests/bpf/progs/test_global_func12.c @@ -5,7 +5,7 @@ #include "bpf_misc.h"
struct S { - int x; + __u32 x; };
__noinline int foo(const struct S *s) diff --git a/tools/testing/selftests/bpf/progs/test_global_func13.c b/tools/testing/selftests/bpf/progs/test_global_func13.c index 02ea80da75b5..c4afdfc9d92e 100644 --- a/tools/testing/selftests/bpf/progs/test_global_func13.c +++ b/tools/testing/selftests/bpf/progs/test_global_func13.c @@ -5,7 +5,7 @@ #include "bpf_misc.h"
struct S { - int x; + __u32 x; };
__noinline int foo(const struct S *s) diff --git a/tools/testing/selftests/bpf/progs/test_global_func9.c b/tools/testing/selftests/bpf/progs/test_global_func9.c index 1f2cb0159b8d..9138d9bd08fc 100644 --- a/tools/testing/selftests/bpf/progs/test_global_func9.c +++ b/tools/testing/selftests/bpf/progs/test_global_func9.c @@ -5,7 +5,7 @@ #include "bpf_misc.h"
struct S { - int x; + __u32 x; };
struct C { diff --git a/tools/testing/selftests/bpf/progs/test_map_init.c b/tools/testing/selftests/bpf/progs/test_map_init.c index c89d28ead673..311e6ac64588 100644 --- a/tools/testing/selftests/bpf/progs/test_map_init.c +++ b/tools/testing/selftests/bpf/progs/test_map_init.c @@ -22,7 +22,7 @@ int sysenter_getpgid(const void *ctx) /* Just do it for once, when called from our own test prog. This * ensures the map value is only updated for a single CPU. */ - int cur_pid = bpf_get_current_pid_tgid() >> 32; + __u32 cur_pid = bpf_get_current_pid_tgid() >> 32;
if (cur_pid == inPid) bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST); diff --git a/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c b/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c index d9b2ba7ac340..4b8ab8716246 100644 --- a/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c +++ b/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c @@ -102,7 +102,7 @@ int xdp_ingress_v6(struct xdp_md *xdp) opt_state.byte_offset = sizeof(struct tcphdr) + tcp_offset;
/* max number of bytes of options in tcp header is 40 bytes */ - for (int i = 0; i < tcp_hdr_opt_max_opt_checks; i++) { + for (__u32 i = 0; i < tcp_hdr_opt_max_opt_checks; i++) { err = parse_hdr_opt(xdp, &opt_state);
if (err || !opt_state.hdr_bytes_remaining)
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com --- .../testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_skb_ctx.c | 2 +- tools/testing/selftests/bpf/progs/test_snprintf.c | 2 +- tools/testing/selftests/bpf/progs/test_sockmap_strp.c | 2 +- tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp.c | 2 +- 6 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c b/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c index dc6e43bc6a62..bf3ac5c2938c 100644 --- a/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c +++ b/tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c @@ -100,7 +100,7 @@ int xdp_ingress_v6(struct xdp_md *xdp) off += sizeof(struct tcphdr);
/* max number of bytes of options in tcp header is 40 bytes */ - for (int i = 0; i < tcp_hdr_opt_max_opt_checks; i++) { + for (__u32 i = 0; i < tcp_hdr_opt_max_opt_checks; i++) { err = parse_hdr_opt(&ptr, &off, &hdr_bytes_remaining, &server_id);
if (err || !hdr_bytes_remaining) diff --git a/tools/testing/selftests/bpf/progs/test_skb_ctx.c b/tools/testing/selftests/bpf/progs/test_skb_ctx.c index a724a70c6700..7939a2edc414 100644 --- a/tools/testing/selftests/bpf/progs/test_skb_ctx.c +++ b/tools/testing/selftests/bpf/progs/test_skb_ctx.c @@ -11,7 +11,7 @@ SEC("tc") int process(struct __sk_buff *skb) { __pragma_loop_unroll_full - for (int i = 0; i < 5; i++) { + for (__u32 i = 0; i < 5; i++) { if (skb->cb[i] != i + 1) return 1; skb->cb[i]++; diff --git a/tools/testing/selftests/bpf/progs/test_snprintf.c b/tools/testing/selftests/bpf/progs/test_snprintf.c index 8fda07544023..1aa4835da71a 100644 --- a/tools/testing/selftests/bpf/progs/test_snprintf.c +++ b/tools/testing/selftests/bpf/progs/test_snprintf.c @@ -4,7 +4,7 @@ #include <linux/bpf.h> #include <bpf/bpf_helpers.h>
-__u32 pid = 0; +int pid = 0;
char num_out[64] = {}; long num_ret = 0; diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_strp.c b/tools/testing/selftests/bpf/progs/test_sockmap_strp.c index dde3d5bec515..e9675c45d8ef 100644 --- a/tools/testing/selftests/bpf/progs/test_sockmap_strp.c +++ b/tools/testing/selftests/bpf/progs/test_sockmap_strp.c @@ -2,7 +2,7 @@ #include <linux/bpf.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_endian.h> -int verdict_max_size = 10000; +__u32 verdict_max_size = 10000; struct { __uint(type, BPF_MAP_TYPE_SOCKMAP); __uint(max_entries, 20); diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c index 404124a93892..c7e2d4571a2b 100644 --- a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c +++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c @@ -80,7 +80,7 @@ static __always_inline void set_ipv4_csum(struct iphdr *iph) { __u16 *iph16 = (__u16 *)iph; __u32 csum; - int i; + size_t i;
iph->check = 0;
diff --git a/tools/testing/selftests/bpf/progs/test_xdp.c b/tools/testing/selftests/bpf/progs/test_xdp.c index 8caf58be5818..ce2a9ae26088 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp.c +++ b/tools/testing/selftests/bpf/progs/test_xdp.c @@ -89,7 +89,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp) struct vip vip = {}; int dport; __u32 csum = 0; - int i; + size_t i;
if (iph + 1 > data_end) return XDP_DROP;
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com --- tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c index 67a77944ef29..12ad0ec91021 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c @@ -89,7 +89,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xd struct vip vip = {}; int dport; __u32 csum = 0; - int i; + size_t i;
__builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); __builtin_memset(iph_buffer_tcp, 0, sizeof(iph_buffer_tcp)); diff --git a/tools/testing/selftests/bpf/progs/test_xdp_loop.c b/tools/testing/selftests/bpf/progs/test_xdp_loop.c index 93267a68825b..e9b7bbff5c23 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_loop.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_loop.c @@ -85,7 +85,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp) struct vip vip = {}; int dport; __u32 csum = 0; - int i; + size_t i;
if (iph + 1 > data_end) return XDP_DROP; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c index fad94e41cef9..85ef3c0a3e20 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -372,7 +372,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval,
next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full - for (int i = 0; i < sizeof(struct iphdr) >> 1; i++) + for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr))) @@ -423,7 +423,7 @@ int send_icmp_reply(void *data, void *data_end) iph->check = 0; next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full - for (int i = 0; i < sizeof(struct iphdr) >> 1; i++) + for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); return swap_mac_and_send(data, data_end); diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c index 44190efcdba2..f99957773c3a 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -20,13 +20,13 @@ __u64 uretprobe_multi_func_3_result = 0;
__u64 uprobe_multi_sleep_result = 0;
-int pid = 0; +__u32 pid = 0; int child_pid = 0; int child_tid = 0; int child_pid_usdt = 0; int child_tid_usdt = 0;
-int expect_pid = 0; +__u32 expect_pid = 0; bool bad_pid_seen = false; bool bad_pid_seen_usdt = false;
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c index 8fbcd69fae22..017f1859ebe8 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c @@ -3,6 +3,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <stdbool.h> +#include <stddef.h> #include "bpf_kfuncs.h" #include "bpf_misc.h"
@@ -10,8 +11,8 @@ char _license[] SEC("license") = "GPL";
int pid = 0;
-int idx_entry = 0; -int idx_return = 0; +size_t idx_entry = 0; +size_t idx_return = 0;
__u64 test_uprobe_cookie_entry[6]; __u64 test_uprobe_cookie_return[3]; diff --git a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c index 75dd922e4e9f..72f9f8c23c93 100644 --- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c +++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c @@ -593,7 +593,7 @@ int loop_inside_iter_volatile_limit(const void *ctx) { struct bpf_iter_num it; int *v, sum = 0; - __u64 i = 0; + __s32 i = 0;
bpf_iter_num_new(&it, 0, ARR2_SZ); while ((v = bpf_iter_num_next(&it))) {
On 9/25/25 12:35 PM, Mehdi Ben Hadj Khelifa wrote:
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com
Pls write some better commit messages and not just copy/paste the same $subj/ message every time; proper sentences w/o the weird " -" indent. Also say why this is needed in the commit message, and add a reference to the commit which initially added this as a TODO, i.e. 495d2d8133fd ("selftests/bpf: Attempt to build BPF programs with -Wsign-compare"). If you group these, then maybe also include the parts of the compiler-emitted warnings during build which are relevant to the code changes you do here.
tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c index 67a77944ef29..12ad0ec91021 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c @@ -89,7 +89,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xd struct vip vip = {}; int dport; __u32 csum = 0;
- int i;
- size_t i;
__builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); __builtin_memset(iph_buffer_tcp, 0, sizeof(iph_buffer_tcp)); diff --git a/tools/testing/selftests/bpf/progs/test_xdp_loop.c b/tools/testing/selftests/bpf/progs/test_xdp_loop.c index 93267a68825b..e9b7bbff5c23 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_loop.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_loop.c @@ -85,7 +85,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp) struct vip vip = {}; int dport; __u32 csum = 0;
- int i;
- size_t i;
if (iph + 1 > data_end) return XDP_DROP; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c index fad94e41cef9..85ef3c0a3e20 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -372,7 +372,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full
- for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
- for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
@@ -423,7 +423,7 @@ int send_icmp_reply(void *data, void *data_end) iph->check = 0; next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full
- for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
- for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); return swap_mac_and_send(data, data_end);
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c index 44190efcdba2..f99957773c3a 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -20,13 +20,13 @@ __u64 uretprobe_multi_func_3_result = 0; __u64 uprobe_multi_sleep_result = 0; -int pid = 0; +__u32 pid = 0; int child_pid = 0; int child_tid = 0; int child_pid_usdt = 0; int child_tid_usdt = 0; -int expect_pid = 0; +__u32 expect_pid = 0; bool bad_pid_seen = false; bool bad_pid_seen_usdt = false; diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c index 8fbcd69fae22..017f1859ebe8 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c @@ -3,6 +3,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <stdbool.h> +#include <stddef.h> #include "bpf_kfuncs.h" #include "bpf_misc.h" @@ -10,8 +11,8 @@ char _license[] SEC("license") = "GPL"; int pid = 0; -int idx_entry = 0; -int idx_return = 0; +size_t idx_entry = 0; +size_t idx_return = 0; __u64 test_uprobe_cookie_entry[6]; __u64 test_uprobe_cookie_return[3]; diff --git a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c index 75dd922e4e9f..72f9f8c23c93 100644 --- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c +++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c @@ -593,7 +593,7 @@ int loop_inside_iter_volatile_limit(const void *ctx) { struct bpf_iter_num it; int *v, sum = 0;
- __u64 i = 0;
- __s32 i = 0;
bpf_iter_num_new(&it, 0, ARR2_SZ); while ((v = bpf_iter_num_next(&it))) {
On 9/25/25 4:04 PM, Daniel Borkmann wrote:
On 9/25/25 12:35 PM, Mehdi Ben Hadj Khelifa wrote:
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com
Pls write some better commit messages and not just copy/paste the same $subj/ message every time; proper sentences w/o the weird " -" indent.
Understood, though the changes are very similar / are the same with the same goal that's why it made sense to me to do that and I will remove the - in future commits.> Also say
why this is needed in the commit message, and add a reference to the commit which initially added this as a TODO, i.e. 495d2d8133fd ("selftests/bpf: Attempt to build BPF programs with -Wsign-compare").
I will do that in the upcoming version.
If you group these, then maybe also include the parts of the compiler-emitted warnings during build which are relevant to the code changes you do here.
Okay. I will do that. Should i send a v4 with the recommended changes but not including the rest of the files meaning the ones that I haven't uploaded in this patch series which contain type casting or should i just make changes for these files in this series? Also will it be better if dropped these versions and made a new patch with v1?
Thank you for your review and time Daniel. Regards, Mehdi
tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c b/ tools/testing/selftests/bpf/progs/test_xdp_dynptr.c index 67a77944ef29..12ad0ec91021 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c @@ -89,7 +89,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xd struct vip vip = {}; int dport; __u32 csum = 0; - int i; + size_t i; __builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); __builtin_memset(iph_buffer_tcp, 0, sizeof(iph_buffer_tcp)); diff --git a/tools/testing/selftests/bpf/progs/test_xdp_loop.c b/ tools/testing/selftests/bpf/progs/test_xdp_loop.c index 93267a68825b..e9b7bbff5c23 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_loop.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_loop.c @@ -85,7 +85,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp) struct vip vip = {}; int dport; __u32 csum = 0; - int i; + size_t i; if (iph + 1 > data_end) return XDP_DROP; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/ tools/testing/selftests/bpf/progs/test_xdp_noinline.c index fad94e41cef9..85ef3c0a3e20 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -372,7 +372,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full - for (int i = 0; i < sizeof(struct iphdr) >> 1; i++) + for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr))) @@ -423,7 +423,7 @@ int send_icmp_reply(void *data, void *data_end) iph->check = 0; next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full - for (int i = 0; i < sizeof(struct iphdr) >> 1; i++) + for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); return swap_mac_and_send(data, data_end); diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/ testing/selftests/bpf/progs/uprobe_multi.c index 44190efcdba2..f99957773c3a 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -20,13 +20,13 @@ __u64 uretprobe_multi_func_3_result = 0; __u64 uprobe_multi_sleep_result = 0; -int pid = 0; +__u32 pid = 0; int child_pid = 0; int child_tid = 0; int child_pid_usdt = 0; int child_tid_usdt = 0; -int expect_pid = 0; +__u32 expect_pid = 0; bool bad_pid_seen = false; bool bad_pid_seen_usdt = false; diff --git a/tools/testing/selftests/bpf/progs/ uprobe_multi_session_recursive.c b/tools/testing/selftests/bpf/progs/ uprobe_multi_session_recursive.c index 8fbcd69fae22..017f1859ebe8 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c @@ -3,6 +3,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <stdbool.h> +#include <stddef.h> #include "bpf_kfuncs.h" #include "bpf_misc.h" @@ -10,8 +11,8 @@ char _license[] SEC("license") = "GPL"; int pid = 0; -int idx_entry = 0; -int idx_return = 0; +size_t idx_entry = 0; +size_t idx_return = 0; __u64 test_uprobe_cookie_entry[6]; __u64 test_uprobe_cookie_return[3]; diff --git a/tools/testing/selftests/bpf/progs/ verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/ verifier_iterating_callbacks.c index 75dd922e4e9f..72f9f8c23c93 100644 --- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c +++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c @@ -593,7 +593,7 @@ int loop_inside_iter_volatile_limit(const void *ctx) { struct bpf_iter_num it; int *v, sum = 0; - __u64 i = 0; + __s32 i = 0; bpf_iter_num_new(&it, 0, ARR2_SZ); while ((v = bpf_iter_num_next(&it))) {
Hi Mehdi, You are trying to do much with the patch series. I don't think it will help much as reviewers will give comments and you will revise the patches. This loop will continue forever.
I totally agree with Daniel. Please write a proper commit message.
While writing a commit message or creating a patch.Please try to give the answers of the following questions. 1) What is the issue which your patch resolves? 2) Are you trying to do more than one thing at a time? Please don't. 3) if a patch modifies more than one file then either these changes inter link with each other or they have similar kind of work.
~~Vivek
On Thu, Sep 25, 2025 at 9:04 PM Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com wrote:
On 9/25/25 4:04 PM, Daniel Borkmann wrote:
On 9/25/25 12:35 PM, Mehdi Ben Hadj Khelifa wrote:
-Change only variable types for correct sign comparisons
Signed-off-by: Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com
Pls write some better commit messages and not just copy/paste the same $subj/ message every time; proper sentences w/o the weird " -" indent.
Understood, though the changes are very similar / are the same with the same goal that's why it made sense to me to do that and I will remove the - in future commits.> Also say
why this is needed in the commit message, and add a reference to the commit which initially added this as a TODO, i.e. 495d2d8133fd ("selftests/bpf: Attempt to build BPF programs with -Wsign-compare").
I will do that in the upcoming version.
If you group these, then maybe also include the parts of the compiler-emitted warnings during build which are relevant to the code changes you do here.
Okay. I will do that. Should i send a v4 with the recommended changes but not including the rest of the files meaning the ones that I haven't uploaded in this patch series which contain type casting or should i just make changes for these files in this series? Also will it be better if dropped these versions and made a new patch with v1?
Thank you for your review and time Daniel. Regards, Mehdi
tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c b/ tools/testing/selftests/bpf/progs/test_xdp_dynptr.c index 67a77944ef29..12ad0ec91021 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c @@ -89,7 +89,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xd struct vip vip = {}; int dport; __u32 csum = 0;
- int i;
- size_t i; __builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); __builtin_memset(iph_buffer_tcp, 0, sizeof(iph_buffer_tcp));
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_loop.c b/ tools/testing/selftests/bpf/progs/test_xdp_loop.c index 93267a68825b..e9b7bbff5c23 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_loop.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_loop.c @@ -85,7 +85,7 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp) struct vip vip = {}; int dport; __u32 csum = 0;
- int i;
- size_t i; if (iph + 1 > data_end) return XDP_DROP;
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c b/ tools/testing/selftests/bpf/progs/test_xdp_noinline.c index fad94e41cef9..85ef3c0a3e20 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_noinline.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_noinline.c @@ -372,7 +372,7 @@ bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval, next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full
- for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
- for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
@@ -423,7 +423,7 @@ int send_icmp_reply(void *data, void *data_end) iph->check = 0; next_iph_u16 = (__u16 *) iph; __pragma_loop_unroll_full
- for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
- for (size_t i = 0; i < sizeof(struct iphdr) >> 1; i++) csum += *next_iph_u16++; iph->check = ~((csum & 0xffff) + (csum >> 16)); return swap_mac_and_send(data, data_end);
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/ testing/selftests/bpf/progs/uprobe_multi.c index 44190efcdba2..f99957773c3a 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c @@ -20,13 +20,13 @@ __u64 uretprobe_multi_func_3_result = 0; __u64 uprobe_multi_sleep_result = 0; -int pid = 0; +__u32 pid = 0; int child_pid = 0; int child_tid = 0; int child_pid_usdt = 0; int child_tid_usdt = 0; -int expect_pid = 0; +__u32 expect_pid = 0; bool bad_pid_seen = false; bool bad_pid_seen_usdt = false; diff --git a/tools/testing/selftests/bpf/progs/ uprobe_multi_session_recursive.c b/tools/testing/selftests/bpf/progs/ uprobe_multi_session_recursive.c index 8fbcd69fae22..017f1859ebe8 100644 --- a/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c +++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_recursive.c @@ -3,6 +3,7 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <stdbool.h> +#include <stddef.h> #include "bpf_kfuncs.h" #include "bpf_misc.h" @@ -10,8 +11,8 @@ char _license[] SEC("license") = "GPL"; int pid = 0; -int idx_entry = 0; -int idx_return = 0; +size_t idx_entry = 0; +size_t idx_return = 0; __u64 test_uprobe_cookie_entry[6]; __u64 test_uprobe_cookie_return[3]; diff --git a/tools/testing/selftests/bpf/progs/ verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/ verifier_iterating_callbacks.c index 75dd922e4e9f..72f9f8c23c93 100644 --- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c +++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c @@ -593,7 +593,7 @@ int loop_inside_iter_volatile_limit(const void *ctx) { struct bpf_iter_num it; int *v, sum = 0;
- __u64 i = 0;
- __s32 i = 0; bpf_iter_num_new(&it, 0, ARR2_SZ); while ((v = bpf_iter_num_next(&it))) {
On Thu, Sep 25, 2025 at 2:36 AM Mehdi Ben Hadj Khelifa mehdi.benhadjkhelifa@gmail.com wrote:
This series is preparing to add the -Wsign-compare C compilation flag to the Makefile for bpf selftests as requested by a TODO to help avoid implicit type conversions and have predictable behavior.
Changelog:
Changes from v2:
-Split up the patch into a patch series as suggested by vivek
-Include only changes to variable types with no casting by my mentor david
-Removed the -Wsign-compare in Makefile to avoid compilation errors until adding casting for rest of comparisons.
Link:https://lore.kernel.org/bpf/20250924195731.6374-1-mehdi.benhadjkhelifa@gmail...
Changes from v1:
- Fix CI failed builds where it failed due to do missing .c and
.h files in my patch for working in mainline.
Link:https://lore.kernel.org/bpf/20250924162408.815137-1-mehdi.benhadjkhelifa@gma...
Mehdi Ben Hadj Khelifa (3): selftests/bpf: Prepare to add -Wsign-compare for bpf tests selftests/bpf: Prepare to add -Wsign-compare for bpf tests selftests/bpf: Prepare to add -Wsign-compare for bpf tests
I see little value in these transformations. Did we catch any real issue here? All this type casting and replacement is just churn.
I certainly don't want such churn in libbpf, and I'd leave BPF selftests as is as well. int vs u64 can have subtle and non-obvious implications for BPF code generation (for no-alu32 variants especially), and I think BPF CI already exposed some of those already.
I think we can live without -Wsign-compare just fine.
tools/testing/selftests/bpf/progs/test_global_func11.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func12.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func13.c | 2 +- tools/testing/selftests/bpf/progs/test_global_func9.c | 2 +- tools/testing/selftests/bpf/progs/test_map_init.c | 2 +- tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c | 2 +- .../selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_skb_ctx.c | 2 +- tools/testing/selftests/bpf/progs/test_snprintf.c | 2 +- tools/testing/selftests/bpf/progs/test_sockmap_strp.c | 2 +- tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_loop.c | 2 +- tools/testing/selftests/bpf/progs/test_xdp_noinline.c | 4 ++-- tools/testing/selftests/bpf/progs/uprobe_multi.c | 4 ++-- .../selftests/bpf/progs/uprobe_multi_session_recursive.c | 5 +++-- .../selftests/bpf/progs/verifier_iterating_callbacks.c | 2 +- 18 files changed, 22 insertions(+), 21 deletions(-)
-- 2.51.0
I see little value in these transformations. Did we catch any real issue here? All this type casting and replacement is just churn.
I certainly don't want such churn in libbpf, and I'd leave BPF selftests as is as well. int vs u64 can have subtle and non-obvious implications for BPF code generation (for no-alu32 variants especially), and I think BPF CI already exposed some of those already.
I think we can live without -Wsign-compare just fine.
I was convinced by [1] that this needed to be done not just for current version of the code but for future code being more robust initially.I have already done all the work and I can follow daniel's suggestion for the next version.Otherwise,This means then that the TODO comment to add that compiler warning in the makefile needs to be removed.
Also I wanted to ask since the CI bot had success with my patch.What does this [2] mean exactly.
Thank you for your time reviewing and helping.
Regards, Mehdi
[1]:https://github.com/kernel-patches/bpf/commit/495d2d8133fd1407519170a5238f455... [2]:https://github.com/kernel-patches/bpf/actions/runs/18006172526
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