[PATCH] dlinfo.3: Document the RTLD_DI_PHDR request

[Florian Weimer <fweimer@redhat.com>]

First added in glibc 2.36, backported upstream to glibc 2.34,
so mention 2.34.1 for the first version.

Signed-off-by: Florian Weimer <fweimer@redhat.com>

---
 man/man3/dlinfo.3 | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/man/man3/dlinfo.3 b/man/man3/dlinfo.3
index 84b696f8c..8d61f81e8 100644
--- a/man/man3/dlinfo.3
+++ b/man/man3/dlinfo.3
@@ -194,10 +194,23 @@ If this object does not define a PT_TLS segment,
 or if the calling thread has not allocated a block for it,
 NULL is placed in
 .IR *info .
+.TP
+.BR RTLD_DI_PHDR " (\fIconst ElfW(Phdr *)\fP, since glibc 2.34.1)"
+.\" glibc commit d056c212130280c0a54d9a4f72170ec621b70ce5 (2.36)
+.\" glibc commit d056c212130280c0a54d9a4f72170ec621b70ce5 (2.35)
+.\" glibc commit 91c2e6c3db44297bf4cb3a2e3c40236c5b6a0b23 (2.34)
+Obtain the address of this shared object's program header and place it
+in
+.IR *info .
+This
+.B dlinfo
+call returns the number of program headers in the shared object.
 .SH RETURN VALUE
 On success,
 .BR dlinfo ()
-returns 0.
+returns 0
+(if not specified explicitly),
+or a positive value corresponding to the request.
 On failure, it returns \-1; the error can be diagnosed using
 .BR dlerror (3).
 .SH ATTRIBUTES

base-commit: 6a7f1461b0e5474d50ef1920558dec103c0c058f