Merge remote-tracking branch 'torvalds/master' into perf/core
[sfrench/cifs-2.6.git] / tools / objtool / orc_gen.c
index 9ce68b385a1b81f43789a86cb3720e3e9485348c..738aa5021bc4b6d6fbd55d7edb7549e2bb4134c6 100644 (file)
@@ -9,93 +9,91 @@
 #include <linux/objtool.h>
 #include <asm/orc_types.h>
 
-#include "check.h"
-#include "warn.h"
+#include <objtool/check.h>
+#include <objtool/warn.h>
+#include <objtool/endianness.h>
 
-int create_orc(struct objtool_file *file)
+static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi)
 {
-       struct instruction *insn;
+       struct instruction *insn = container_of(cfi, struct instruction, cfi);
+       struct cfi_reg *bp = &cfi->regs[CFI_BP];
 
-       for_each_insn(file, insn) {
-               struct orc_entry *orc = &insn->orc;
-               struct cfi_reg *cfa = &insn->cfi.cfa;
-               struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
+       memset(orc, 0, sizeof(*orc));
 
-               if (!insn->sec->text)
-                       continue;
-
-               orc->end = insn->cfi.end;
-
-               if (cfa->base == CFI_UNDEFINED) {
-                       orc->sp_reg = ORC_REG_UNDEFINED;
-                       continue;
-               }
+       orc->end = cfi->end;
 
-               switch (cfa->base) {
-               case CFI_SP:
-                       orc->sp_reg = ORC_REG_SP;
-                       break;
-               case CFI_SP_INDIRECT:
-                       orc->sp_reg = ORC_REG_SP_INDIRECT;
-                       break;
-               case CFI_BP:
-                       orc->sp_reg = ORC_REG_BP;
-                       break;
-               case CFI_BP_INDIRECT:
-                       orc->sp_reg = ORC_REG_BP_INDIRECT;
-                       break;
-               case CFI_R10:
-                       orc->sp_reg = ORC_REG_R10;
-                       break;
-               case CFI_R13:
-                       orc->sp_reg = ORC_REG_R13;
-                       break;
-               case CFI_DI:
-                       orc->sp_reg = ORC_REG_DI;
-                       break;
-               case CFI_DX:
-                       orc->sp_reg = ORC_REG_DX;
-                       break;
-               default:
-                       WARN_FUNC("unknown CFA base reg %d",
-                                 insn->sec, insn->offset, cfa->base);
-                       return -1;
-               }
+       if (cfi->cfa.base == CFI_UNDEFINED) {
+               orc->sp_reg = ORC_REG_UNDEFINED;
+               return 0;
+       }
 
-               switch(bp->base) {
-               case CFI_UNDEFINED:
-                       orc->bp_reg = ORC_REG_UNDEFINED;
-                       break;
-               case CFI_CFA:
-                       orc->bp_reg = ORC_REG_PREV_SP;
-                       break;
-               case CFI_BP:
-                       orc->bp_reg = ORC_REG_BP;
-                       break;
-               default:
-                       WARN_FUNC("unknown BP base reg %d",
-                                 insn->sec, insn->offset, bp->base);
-                       return -1;
-               }
+       switch (cfi->cfa.base) {
+       case CFI_SP:
+               orc->sp_reg = ORC_REG_SP;
+               break;
+       case CFI_SP_INDIRECT:
+               orc->sp_reg = ORC_REG_SP_INDIRECT;
+               break;
+       case CFI_BP:
+               orc->sp_reg = ORC_REG_BP;
+               break;
+       case CFI_BP_INDIRECT:
+               orc->sp_reg = ORC_REG_BP_INDIRECT;
+               break;
+       case CFI_R10:
+               orc->sp_reg = ORC_REG_R10;
+               break;
+       case CFI_R13:
+               orc->sp_reg = ORC_REG_R13;
+               break;
+       case CFI_DI:
+               orc->sp_reg = ORC_REG_DI;
+               break;
+       case CFI_DX:
+               orc->sp_reg = ORC_REG_DX;
+               break;
+       default:
+               WARN_FUNC("unknown CFA base reg %d",
+                         insn->sec, insn->offset, cfi->cfa.base);
+               return -1;
+       }
 
-               orc->sp_offset = cfa->offset;
-               orc->bp_offset = bp->offset;
-               orc->type = insn->cfi.type;
+       switch (bp->base) {
+       case CFI_UNDEFINED:
+               orc->bp_reg = ORC_REG_UNDEFINED;
+               break;
+       case CFI_CFA:
+               orc->bp_reg = ORC_REG_PREV_SP;
+               break;
+       case CFI_BP:
+               orc->bp_reg = ORC_REG_BP;
+               break;
+       default:
+               WARN_FUNC("unknown BP base reg %d",
+                         insn->sec, insn->offset, bp->base);
+               return -1;
        }
 
+       orc->sp_offset = cfi->cfa.offset;
+       orc->bp_offset = bp->offset;
+       orc->type = cfi->type;
+
        return 0;
 }
 
-static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
-                               unsigned int idx, struct section *insn_sec,
-                               unsigned long insn_off, struct orc_entry *o)
+static int write_orc_entry(struct elf *elf, struct section *orc_sec,
+                          struct section *ip_rsec, unsigned int idx,
+                          struct section *insn_sec, unsigned long insn_off,
+                          struct orc_entry *o)
 {
        struct orc_entry *orc;
        struct reloc *reloc;
 
        /* populate ORC data */
-       orc = (struct orc_entry *)u_sec->data->d_buf + idx;
+       orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
        memcpy(orc, o, sizeof(*orc));
+       orc->sp_offset = bswap_if_needed(orc->sp_offset);
+       orc->bp_offset = bswap_if_needed(orc->bp_offset);
 
        /* populate reloc for ip */
        reloc = malloc(sizeof(*reloc));
@@ -114,102 +112,149 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti
 
        reloc->type = R_X86_64_PC32;
        reloc->offset = idx * sizeof(int);
-       reloc->sec = ip_relocsec;
+       reloc->sec = ip_rsec;
 
        elf_add_reloc(elf, reloc);
 
        return 0;
 }
 
-int create_orc_sections(struct objtool_file *file)
-{
-       struct instruction *insn, *prev_insn;
-       struct section *sec, *u_sec, *ip_relocsec;
-       unsigned int idx;
+struct orc_list_entry {
+       struct list_head list;
+       struct orc_entry orc;
+       struct section *insn_sec;
+       unsigned long insn_off;
+};
 
-       struct orc_entry empty = {
-               .sp_reg = ORC_REG_UNDEFINED,
-               .bp_reg  = ORC_REG_UNDEFINED,
-               .type    = UNWIND_HINT_TYPE_CALL,
-       };
+static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,
+                       struct section *sec, unsigned long offset)
+{
+       struct orc_list_entry *entry = malloc(sizeof(*entry));
 
-       sec = find_section_by_name(file->elf, ".orc_unwind");
-       if (sec) {
-               WARN("file already has .orc_unwind section, skipping");
+       if (!entry) {
+               WARN("malloc failed");
                return -1;
        }
 
-       /* count the number of needed orcs */
-       idx = 0;
-       for_each_sec(file, sec) {
-               if (!sec->text)
-                       continue;
-
-               prev_insn = NULL;
-               sec_for_each_insn(file, sec, insn) {
-                       if (!prev_insn ||
-                           memcmp(&insn->orc, &prev_insn->orc,
-                                  sizeof(struct orc_entry))) {
-                               idx++;
-                       }
-                       prev_insn = insn;
-               }
-
-               /* section terminator */
-               if (prev_insn)
-                       idx++;
-       }
-       if (!idx)
-               return -1;
+       entry->orc      = *orc;
+       entry->insn_sec = sec;
+       entry->insn_off = offset;
 
+       list_add_tail(&entry->list, orc_list);
+       return 0;
+}
 
-       /* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
-       sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), idx);
-       if (!sec)
-               return -1;
+static unsigned long alt_group_len(struct alt_group *alt_group)
+{
+       return alt_group->last_insn->offset +
+              alt_group->last_insn->len -
+              alt_group->first_insn->offset;
+}
 
-       ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
-       if (!ip_relocsec)
-               return -1;
+int orc_create(struct objtool_file *file)
+{
+       struct section *sec, *ip_rsec, *orc_sec;
+       unsigned int nr = 0, idx = 0;
+       struct orc_list_entry *entry;
+       struct list_head orc_list;
 
-       /* create .orc_unwind section */
-       u_sec = elf_create_section(file->elf, ".orc_unwind", 0,
-                                  sizeof(struct orc_entry), idx);
+       struct orc_entry null = {
+               .sp_reg  = ORC_REG_UNDEFINED,
+               .bp_reg  = ORC_REG_UNDEFINED,
+               .type    = UNWIND_HINT_TYPE_CALL,
+       };
 
-       /* populate sections */
-       idx = 0;
+       /* Build a deduplicated list of ORC entries: */
+       INIT_LIST_HEAD(&orc_list);
        for_each_sec(file, sec) {
+               struct orc_entry orc, prev_orc = {0};
+               struct instruction *insn;
+               bool empty = true;
+
                if (!sec->text)
                        continue;
 
-               prev_insn = NULL;
                sec_for_each_insn(file, sec, insn) {
-                       if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
-                                                sizeof(struct orc_entry))) {
+                       struct alt_group *alt_group = insn->alt_group;
+                       int i;
 
-                               if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
-                                                    insn->sec, insn->offset,
-                                                    &insn->orc))
+                       if (!alt_group) {
+                               if (init_orc_entry(&orc, &insn->cfi))
                                        return -1;
+                               if (!memcmp(&prev_orc, &orc, sizeof(orc)))
+                                       continue;
+                               if (orc_list_add(&orc_list, &orc, sec,
+                                                insn->offset))
+                                       return -1;
+                               nr++;
+                               prev_orc = orc;
+                               empty = false;
+                               continue;
+                       }
 
-                               idx++;
+                       /*
+                        * Alternatives can have different stack layout
+                        * possibilities (but they shouldn't conflict).
+                        * Instead of traversing the instructions, use the
+                        * alt_group's flattened byte-offset-addressed CFI
+                        * array.
+                        */
+                       for (i = 0; i < alt_group_len(alt_group); i++) {
+                               struct cfi_state *cfi = alt_group->cfi[i];
+                               if (!cfi)
+                                       continue;
+                               if (init_orc_entry(&orc, cfi))
+                                       return -1;
+                               if (!memcmp(&prev_orc, &orc, sizeof(orc)))
+                                       continue;
+                               if (orc_list_add(&orc_list, &orc, insn->sec,
+                                                insn->offset + i))
+                                       return -1;
+                               nr++;
+                               prev_orc = orc;
+                               empty = false;
                        }
-                       prev_insn = insn;
-               }
 
-               /* section terminator */
-               if (prev_insn) {
-                       if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
-                                            prev_insn->sec,
-                                            prev_insn->offset + prev_insn->len,
-                                            &empty))
-                               return -1;
+                       /* Skip to the end of the alt_group */
+                       insn = alt_group->last_insn;
+               }
 
-                       idx++;
+               /* Add a section terminator */
+               if (!empty) {
+                       orc_list_add(&orc_list, &null, sec, sec->len);
+                       nr++;
                }
        }
+       if (!nr)
+               return 0;
+
+       /* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */
+       sec = find_section_by_name(file->elf, ".orc_unwind");
+       if (sec) {
+               WARN("file already has .orc_unwind section, skipping");
+               return -1;
+       }
+       orc_sec = elf_create_section(file->elf, ".orc_unwind", 0,
+                                    sizeof(struct orc_entry), nr);
+       if (!orc_sec)
+               return -1;
+
+       sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
+       if (!sec)
+               return -1;
+       ip_rsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+       if (!ip_rsec)
+               return -1;
+
+       /* Write ORC entries to sections: */
+       list_for_each_entry(entry, &orc_list, list) {
+               if (write_orc_entry(file->elf, orc_sec, ip_rsec, idx++,
+                                   entry->insn_sec, entry->insn_off,
+                                   &entry->orc))
+                       return -1;
+       }
 
-       if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
+       if (elf_rebuild_reloc_section(file->elf, ip_rsec))
                return -1;
 
        return 0;