Merge branch 'for-6.15/amd_sfh' into for-linus

From: Mario Limonciello <mario.limonciello@amd.com>

Some platforms include a human presence detection (HPD) sensor. When
enabled and a user is detected a wake event will be emitted from the
sensor fusion hub that software can react to.

Example use cases are "wake from suspend on approach" or to "lock
when leaving".

This is currently enabled by default on supported systems, but users
can't control it. This essentially means that wake on approach is
enabled which is a really surprising behavior to users that don't
expect it.

Instead of defaulting to enabled add a sysfs knob that users can
use to enable the feature if desirable and set it to disabled by
default.

1 files changed, 50 insertions, 3 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 66173ddb5a2df..194809da51725 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1731,12 +1731,24 @@ static int sys_memfd_create(const char *name, unsigned flags)
 #ifndef MFD_CLOEXEC
 #define MFD_CLOEXEC 0x0001U
 #endif
+#ifndef MFD_NOEXEC_SEAL
+#define MFD_NOEXEC_SEAL 0x0008U
+#endif
 
 static int create_placeholder_fd(void)
 {
+	unsigned int flags = MFD_CLOEXEC | MFD_NOEXEC_SEAL;
+	const char *name = "libbpf-placeholder-fd";
 	int fd;
 
-	fd = ensure_good_fd(sys_memfd_create("libbpf-placeholder-fd", MFD_CLOEXEC));
+	fd = ensure_good_fd(sys_memfd_create(name, flags));
+	if (fd >= 0)
+		return fd;
+	else if (errno != EINVAL)
+		return -errno;
+
+	/* Possibly running on kernel without MFD_NOEXEC_SEAL */
+	fd = ensure_good_fd(sys_memfd_create(name, flags & ~MFD_NOEXEC_SEAL));
 	if (fd < 0)
 		return -errno;
 	return fd;
@@ -11375,9 +11387,33 @@ static int avail_kallsyms_cb(unsigned long long sym_addr, char sym_type,
 	struct kprobe_multi_resolve *res = data->res;
 	int err;
 
-	if (!bsearch(&sym_name, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp))
+	if (!glob_match(sym_name, res->pattern))
 		return 0;
 
+	if (!bsearch(&sym_name, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp)) {
+		/* Some versions of kernel strip out .llvm.<hash> suffix from
+		 * function names reported in available_filter_functions, but
+		 * don't do so for kallsyms. While this is clearly a kernel
+		 * bug (fixed by [0]) we try to accommodate that in libbpf to
+		 * make multi-kprobe usability a bit better: if no match is
+		 * found, we will strip .llvm. suffix and try one more time.
+		 *
+		 *   [0] fb6a421fb615 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG")
+		 */
+		char sym_trim[256], *psym_trim = sym_trim, *sym_sfx;
+
+		if (!(sym_sfx = strstr(sym_name, ".llvm.")))
+			return 0;
+
+		/* psym_trim vs sym_trim dance is done to avoid pointer vs array
+		 * coercion differences and get proper `const char **` pointer
+		 * which avail_func_cmp() expects
+		 */
+		snprintf(sym_trim, sizeof(sym_trim), "%.*s", (int)(sym_sfx - sym_name), sym_name);
+		if (!bsearch(&psym_trim, data->syms, data->cnt, sizeof(*data->syms), avail_func_cmp))
+			return 0;
+	}
+
 	err = libbpf_ensure_mem((void **)&res->addrs, &res->cap, sizeof(*res->addrs), res->cnt + 1);
 	if (err)
 		return err;
@@ -11522,7 +11558,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
 	struct bpf_link *link = NULL;
 	const unsigned long *addrs;
 	int err, link_fd, prog_fd;
-	bool retprobe, session;
+	bool retprobe, session, unique_match;
 	const __u64 *cookies;
 	const char **syms;
 	size_t cnt;
@@ -11541,6 +11577,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
 	addrs   = OPTS_GET(opts, addrs, false);
 	cnt     = OPTS_GET(opts, cnt, false);
 	cookies = OPTS_GET(opts, cookies, false);
+	unique_match = OPTS_GET(opts, unique_match, false);
 
 	if (!pattern && !addrs && !syms)
 		return libbpf_err_ptr(-EINVAL);
@@ -11548,6 +11585,8 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
 		return libbpf_err_ptr(-EINVAL);
 	if (!pattern && !cnt)
 		return libbpf_err_ptr(-EINVAL);
+	if (!pattern && unique_match)
+		return libbpf_err_ptr(-EINVAL);
 	if (addrs && syms)
 		return libbpf_err_ptr(-EINVAL);
 
@@ -11558,6 +11597,14 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
 			err = libbpf_available_kallsyms_parse(&res);
 		if (err)
 			goto error;
+
+		if (unique_match && res.cnt != 1) {
+			pr_warn("prog '%s': failed to find a unique match for '%s' (%zu matches)\n",
+				prog->name, pattern, res.cnt);
+			err = -EINVAL;
+			goto error;
+		}
+
 		addrs = res.addrs;
 		cnt = res.cnt;
 	}