Commit 78e4a955 authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'libbpf: BTF typed dump cleanups' 



Alan Maguire says:

====================

Fix issues with libbpf BTF typed dump code.  Patch 1 addresses handling
of unaligned data. Patch 2 fixes issues Andrii noticed when compiling
on ppc64le.  Patch 3 simplifies typed dump by getting rid of allocation
of dump data structure which tracks dump state etc.

Changes since v1:

 - Andrii suggested using a function instead of a macro for checking
   alignment of data, and pointed out that we need to consider dump
   ptr size versus native pointer size (patch 1)
====================

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents 068dfc65 add192f8

tools/lib/bpf/btf_dump.c

+30 −11
Original line number Diff line number Diff line
@@ -1654,6 +1654,11 @@ static int btf_dump_base_type_check_zero(struct btf_dump *d, 
	return 0;

}



static bool ptr_is_aligned(const void *data, int data_sz)

{

	return ((uintptr_t)data) % data_sz == 0;

}



static int btf_dump_int_data(struct btf_dump *d,

			     const struct btf_type *t,

			     __u32 type_id,
@@ -1672,7 +1677,7 @@ static int btf_dump_int_data(struct btf_dump *d, 
	/* handle packed int data - accesses of integers not aligned on

	 * int boundaries can cause problems on some platforms.

	 */

	if (((uintptr_t)data) % sz)

	if (!ptr_is_aligned(data, sz))

		return btf_dump_bitfield_data(d, t, data, 0, 0);



	switch (sz) {
@@ -1739,7 +1744,7 @@ static int btf_dump_float_data(struct btf_dump *d, 
	int sz = t->size;



	/* handle unaligned data; copy to local union */

	if (((uintptr_t)data) % sz) {

	if (!ptr_is_aligned(data, sz)) {

		memcpy(&fl, data, sz);

		flp = &fl;

	}
@@ -1892,12 +1897,27 @@ static int btf_dump_struct_data(struct btf_dump *d, 
	return err;

}



union ptr_data {

	unsigned int p;

	unsigned long long lp;

};



static int btf_dump_ptr_data(struct btf_dump *d,

			      const struct btf_type *t,

			      __u32 id,

			      const void *data)

{

	if (ptr_is_aligned(data, d->ptr_sz) && d->ptr_sz == sizeof(void *)) {

		btf_dump_type_values(d, "%p", *(void **)data);

	} else {

		union ptr_data pt;



		memcpy(&pt, data, d->ptr_sz);

		if (d->ptr_sz == 4)

			btf_dump_type_values(d, "0x%x", pt.p);

		else

			btf_dump_type_values(d, "0x%llx", pt.lp);

	}

	return 0;

}
@@ -1910,7 +1930,7 @@ static int btf_dump_get_enum_value(struct btf_dump *d, 
	int sz = t->size;



	/* handle unaligned enum value */

	if (((uintptr_t)data) % sz) {

	if (!ptr_is_aligned(data, sz)) {

		*value = (__s64)btf_dump_bitfield_get_data(d, t, data, 0, 0);

		return 0;

	}
@@ -1989,8 +2009,8 @@ static int btf_dump_type_data_check_overflow(struct btf_dump *d, 
	__s64 size = btf__resolve_size(d->btf, id);



	if (size < 0 || size >= INT_MAX) {

		pr_warn("unexpected size [%lld] for id [%u]\n",

			size, id);

		pr_warn("unexpected size [%zu] for id [%u]\n",

			(size_t)size, id);

		return -EINVAL;

	}
@@ -2218,6 +2238,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 
			     const void *data, size_t data_sz,

			     const struct btf_dump_type_data_opts *opts)

{

	struct btf_dump_data typed_dump = {};

	const struct btf_type *t;

	int ret;
@@ -2228,12 +2249,10 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 
	if (!t)

		return libbpf_err(-ENOENT);



	d->typed_dump = calloc(1, sizeof(struct btf_dump_data));

	if (!d->typed_dump)

		return libbpf_err(-ENOMEM);



	d->typed_dump = &typed_dump;

	d->typed_dump->data_end = data + data_sz;

	d->typed_dump->indent_lvl = OPTS_GET(opts, indent_level, 0);



	/* default indent string is a tab */

	if (!opts->indent_str)

		d->typed_dump->indent_str[0] = '\t';
@@ -2247,7 +2266,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id, 


	ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);



	free(d->typed_dump);

	d->typed_dump = NULL;



	return libbpf_err(ret);

}