From 9d5be6ae2a701838670b606b1fae98646f6dced6 Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Sat, 1 Jun 2024 08:44:28 -0400 Subject: vlib: clean up r2 plugin registration relocator Thanks, Eliot! Type: fix Change-Id: I3737f62d08d5cd2db803af86285f9a2e456bab72 Signed-off-by: Dave Barach --- src/vlib/unix/plugin.c | 52 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 9 deletions(-) diff --git a/src/vlib/unix/plugin.c b/src/vlib/unix/plugin.c index 5cac9abc8fe..77e4633e14a 100644 --- a/src/vlib/unix/plugin.c +++ b/src/vlib/unix/plugin.c @@ -88,19 +88,14 @@ extract (u8 * sp, u8 * ep) */ static clib_error_t * -r2_to_reg (elf_main_t * em, vlib_plugin_r2_t * r2, - vlib_plugin_registration_t * reg) +r2_to_reg (elf_main_t *em, vlib_plugin_r2_t *r2, + vlib_plugin_registration_t *reg, elf_section_t *data_section) { - clib_error_t *error; - elf_section_t *section; uword data_segment_offset; u8 *data; /* It turns out that the strings land in the ".data" section */ - error = elf_get_section_by_name (em, ".data", §ion); - if (error) - return error; - data = elf_get_section_contents (em, section->index, 1); + data = elf_get_section_contents (em, data_section->index, 1); /* * Offsets in the ".vlib_plugin_r2" section @@ -177,13 +172,52 @@ load_one_plugin (plugin_main_t * pm, plugin_info_t * pi, int from_early_init) error = elf_get_section_by_name (&em, ".vlib_plugin_r2", §ion); if (error == 0) { + elf_section_t *data_section; + elf_relocation_table_t *rt; + elf_relocation_with_addend_t *r; + elf_symbol_table_t *st; + elf64_symbol_t *sym, *symok = 0; + data = elf_get_section_contents (&em, section->index, 1); r2 = (vlib_plugin_r2_t *) data; + + elf_get_section_by_name (&em, ".data", &data_section); + + // Find first symbol in .vlib_plugin_r2 section. + vec_foreach (st, em.symbol_tables) + { + vec_foreach (sym, st->symbols) + { + if (sym->section_index == section->index) + { + symok = sym; + break; + } + } + } + + // Relocate section data as per relocation tables. + if (symok != 0) + { + vec_foreach (rt, em.relocation_tables) + { + vec_foreach (r, rt->relocations) + { + if (r->address >= symok->value && + r->address < symok->value + symok->size) + { + *(uword *) ((void *) data + r->address - symok->value) += + r->addend - data_section->header.exec_address; + } + } + } + } + reg = clib_mem_alloc (sizeof (*reg)); memset (reg, 0, sizeof (*reg)); reg->default_disabled = r2->default_disabled != 0; - error = r2_to_reg (&em, r2, reg); + error = r2_to_reg (&em, r2, reg, data_section); if (error) { PLUGIN_LOG_ERR ("Bad r2 registration: %s\n", (char *) pi->name); -- cgit 1.2.3-korg