Re: [Crash-utility] [PATCH] Fix for "bpf -m|-M" options on Linux 5.3 and later

Fix for the "bpf -m|-M" options on Linux 5.3 and later kernels that contain commit 3539b96e041c06e4317082816d90ec09160aeb11, titled "bpf: group memory related fields in struct bpf_map_memory". Without the patch, the options prints "(unknown)" for MEMLOCK and UID. Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- bpf.c | 22 ++++++++++++++++++++-- defs.h | 3 +++ symbols.c | 6 ++++++ 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/bpf.c b/bpf.c index 056e286..39ced88 100644 --- a/bpf.c +++ b/bpf.c @@ -202,6 +202,13 @@ bpf_init(struct bpf_info *bpf) MEMBER_OFFSET_INIT(bpf_map_user, "bpf_map", "user"); MEMBER_OFFSET_INIT(user_struct_uid, "user_struct", "uid"); + /* Linux 5.3 */ + MEMBER_OFFSET_INIT(bpf_map_memory, "bpf_map", "memory"); + if (VALID_MEMBER(bpf_map_memory)) { + MEMBER_OFFSET_INIT(bpf_map_memory_pages, "bpf_map_memory", "pages"); + MEMBER_OFFSET_INIT(bpf_map_memory_user, "bpf_map_memory", "user"); + } + if (!bpf_type_size_init()) { bpf->status = FALSE; command_not_supported(); @@ -576,7 +583,11 @@ do_map_only: fprintf(fp, "(unknown)"); fprintf(fp, " MEMLOCK: "); - if (VALID_MEMBER(bpf_map_pages)) { + if (VALID_MEMBER(bpf_map_memory) && VALID_MEMBER(bpf_map_memory_pages)) { + map_pages = UINT(bpf->bpf_map_buf + OFFSET(bpf_map_memory) + + OFFSET(bpf_map_memory_pages)); + fprintf(fp, "%d\n", map_pages * PAGESIZE()); + } else if (VALID_MEMBER(bpf_map_pages)) { map_pages = UINT(bpf->bpf_map_buf + OFFSET(bpf_map_pages)); fprintf(fp, "%d\n", map_pages * PAGESIZE()); } else @@ -594,8 +605,15 @@ do_map_only: fprintf(fp, "(unknown)\n"); fprintf(fp, " UID: "); - if (VALID_MEMBER(bpf_map_user) && VALID_MEMBER(user_struct_uid)) { + if (VALID_MEMBER(bpf_map_memory) && VALID_MEMBER(bpf_map_memory_user)) + user = ULONG(bpf->bpf_map_buf + OFFSET(bpf_map_memory) + + OFFSET(bpf_map_memory_user)); + else if (VALID_MEMBER(bpf_map_user)) user = ULONG(bpf->bpf_map_buf + OFFSET(bpf_map_user)); + else + user = 0; + + if (user && VALID_MEMBER(user_struct_uid)) { if (readmem(user + OFFSET(user_struct_uid), KVADDR, &uid, sizeof(uint), "user_struct.uid", QUIET|RETURN_ON_ERROR)) fprintf(fp, "%d\n", uid); diff --git a/defs.h b/defs.h index ac24a5d..fbd19b0 100644 --- a/defs.h +++ b/defs.h @@ -2075,6 +2075,9 @@ struct offset_table { /* stash of commonly-used offsets */ long device_private_knode_class; long timerqueue_head_rb_root; long rb_root_cached_rb_leftmost; + long bpf_map_memory; + long bpf_map_memory_pages; + long bpf_map_memory_user; }; struct size_table { /* stash of commonly-used sizes */ diff --git a/symbols.c b/symbols.c index f04e8b5..f1f659b 100644 --- a/symbols.c +++ b/symbols.c @@ -10479,6 +10479,12 @@ dump_offset_table(char *spec, ulong makestruct) OFFSET(bpf_map_name)); fprintf(fp, " bpf_map_user: %ld\n", OFFSET(bpf_map_user)); + fprintf(fp, " bpf_map_memory: %ld\n", + OFFSET(bpf_map_memory)); + fprintf(fp, " bpf_map_memory_pages: %ld\n", + OFFSET(bpf_map_memory_pages)); + fprintf(fp, " bpf_map_memory_user: %ld\n", + OFFSET(bpf_map_memory_user)); fprintf(fp, " bpf_prog_aux_used_map_cnt: %ld\n", OFFSET(bpf_prog_aux_used_map_cnt)); -- 2.24.1