From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/scripts/recordmcount.h | 165 ++++++++++++++++++++++++++++++++++++------------------
1 files changed, 110 insertions(+), 55 deletions(-)
diff --git a/kernel/scripts/recordmcount.h b/kernel/scripts/recordmcount.h
index 9f8339c..1e9baa5 100644
--- a/kernel/scripts/recordmcount.h
+++ b/kernel/scripts/recordmcount.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* recordmcount.h
*
@@ -15,8 +16,6 @@
*
* This conversion to macros was done by:
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
- *
- * Licensed under the GNU General Public License, version 2 (GPLv2).
*/
#undef append_func
#undef is_fake_mcount
@@ -193,15 +192,20 @@
Elf32_Word const *symtab_shndx)
{
unsigned long offset;
+ unsigned short shndx = w2(sym->st_shndx);
int index;
- if (sym->st_shndx != SHN_XINDEX)
- return w2(sym->st_shndx);
+ if (shndx > SHN_UNDEF && shndx < SHN_LORESERVE)
+ return shndx;
- offset = (unsigned long)sym - (unsigned long)symtab;
- index = offset / sizeof(*sym);
+ if (shndx == SHN_XINDEX) {
+ offset = (unsigned long)sym - (unsigned long)symtab;
+ index = offset / sizeof(*sym);
- return w(symtab_shndx[index]);
+ return w(symtab_shndx[index]);
+ }
+
+ return 0;
}
static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0)
@@ -251,7 +255,7 @@
}
/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
-static void append_func(Elf_Ehdr *const ehdr,
+static int append_func(Elf_Ehdr *const ehdr,
Elf_Shdr *const shstr,
uint_t const *const mloc0,
uint_t const *const mlocp,
@@ -283,15 +287,20 @@
set_shnum(ehdr, shdr0, new_shnum);
/* body for new shstrtab */
- ulseek(fd_map, sb.st_size, SEEK_SET);
- uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
- uwrite(fd_map, mc_name, 1 + strlen(mc_name));
+ if (ulseek(sb.st_size, SEEK_SET) < 0)
+ return -1;
+ if (uwrite(old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size) < 0)
+ return -1;
+ if (uwrite(mc_name, 1 + strlen(mc_name)) < 0)
+ return -1;
/* old(modified) Elf_Shdr table, word-byte aligned */
- ulseek(fd_map, t, SEEK_SET);
+ if (ulseek(t, SEEK_SET) < 0)
+ return -1;
t += sizeof(Elf_Shdr) * old_shnum;
- uwrite(fd_map, old_shoff + (void *)ehdr,
- sizeof(Elf_Shdr) * old_shnum);
+ if (uwrite(old_shoff + (void *)ehdr,
+ sizeof(Elf_Shdr) * old_shnum) < 0)
+ return -1;
/* new sections __mcount_loc and .rel__mcount_loc */
t += 2*sizeof(mcsec);
@@ -306,7 +315,8 @@
mcsec.sh_info = 0;
mcsec.sh_addralign = _w(_size);
mcsec.sh_entsize = _w(_size);
- uwrite(fd_map, &mcsec, sizeof(mcsec));
+ if (uwrite(&mcsec, sizeof(mcsec)) < 0)
+ return -1;
mcsec.sh_name = w(old_shstr_sh_size);
mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
@@ -320,14 +330,21 @@
mcsec.sh_info = w(old_shnum);
mcsec.sh_addralign = _w(_size);
mcsec.sh_entsize = _w(rel_entsize);
- uwrite(fd_map, &mcsec, sizeof(mcsec));
- uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
- uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
+ if (uwrite(&mcsec, sizeof(mcsec)) < 0)
+ return -1;
+
+ if (uwrite(mloc0, (void *)mlocp - (void *)mloc0) < 0)
+ return -1;
+ if (uwrite(mrel0, (void *)mrelp - (void *)mrel0) < 0)
+ return -1;
ehdr->e_shoff = _w(new_e_shoff);
- ulseek(fd_map, 0, SEEK_SET);
- uwrite(fd_map, ehdr, sizeof(*ehdr));
+ if (ulseek(0, SEEK_SET) < 0)
+ return -1;
+ if (uwrite(ehdr, sizeof(*ehdr)) < 0)
+ return -1;
+ return 0;
}
static unsigned get_mcountsym(Elf_Sym const *const sym0,
@@ -431,9 +448,9 @@
* that are not going to be traced. The mcount calls here will be converted
* into nops.
*/
-static void nop_mcount(Elf_Shdr const *const relhdr,
- Elf_Ehdr const *const ehdr,
- const char *const txtname)
+static int nop_mcount(Elf_Shdr const *const relhdr,
+ Elf_Ehdr const *const ehdr,
+ const char *const txtname)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
@@ -464,7 +481,7 @@
once = 1;
/* just warn? */
if (!make_nop)
- return;
+ return 0;
}
}
@@ -476,13 +493,15 @@
Elf_Rel rel;
rel = *(Elf_Rel *)relp;
Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop);
- ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET);
- uwrite(fd_map, &rel, sizeof(rel));
+ if (ulseek((void *)relp - (void *)ehdr, SEEK_SET) < 0)
+ return -1;
+ if (uwrite(&rel, sizeof(rel)) < 0)
+ return -1;
}
relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
}
+ return 0;
}
-
/*
* Find a symbol in the given section, to be used as the base for relocating
@@ -494,9 +513,10 @@
* Num: Value Size Type Bind Vis Ndx Name
* 2: 00000000 0 SECTION LOCAL DEFAULT 1
*/
-static unsigned find_secsym_ndx(unsigned const txtndx,
+static int find_secsym_ndx(unsigned const txtndx,
char const *const txtname,
uint_t *const recvalp,
+ unsigned int *sym_index,
Elf_Shdr const *const symhdr,
Elf32_Word const *symtab,
Elf32_Word const *symtab_shndx,
@@ -520,21 +540,20 @@
continue;
*recvalp = _w(symp->st_value);
- return symp - sym0;
+ *sym_index = symp - sym0;
+ return 0;
}
}
fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
txtndx, txtname);
- fail_file();
+ return -1;
}
-
/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
-static char const *
-__has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */
- Elf_Shdr const *const shdr0,
- char const *const shstrtab,
- char const *const fname)
+static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* reltype */
+ Elf_Shdr const *const shdr0,
+ char const *const shstrtab,
+ char const *const fname)
{
/* .sh_info depends on .sh_type == SHT_REL[,A] */
Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
@@ -543,7 +562,7 @@
if (strcmp("__mcount_loc", txtname) == 0) {
fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
fname);
- succeed_file();
+ return already_has_rel_mcount;
}
if (w(txthdr->sh_type) != SHT_PROGBITS ||
!(_w(txthdr->sh_flags) & SHF_EXECINSTR))
@@ -573,6 +592,10 @@
for (; nhdr; --nhdr, ++shdrp) {
txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname);
+ if (txtname == already_has_rel_mcount) {
+ totrelsz = 0;
+ break;
+ }
if (txtname && is_mcounted_section_name(txtname))
totrelsz += _w(shdrp->sh_size);
}
@@ -580,8 +603,8 @@
}
/* Overall supervision for Elf32 ET_REL file. */
-static void
-do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
+static int do_func(Elf_Ehdr *const ehdr, char const *const fname,
+ unsigned const reltype)
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
@@ -597,29 +620,57 @@
Elf32_Word *symtab_shndx;
/* Upper bound on space: assume all relevant relocs are for mcount. */
- unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
- Elf_Rel *const mrel0 = umalloc(totrelsz);
- Elf_Rel * mrelp = mrel0;
+ unsigned totrelsz;
- /* 2*sizeof(address) <= sizeof(Elf_Rel) */
- uint_t *const mloc0 = umalloc(totrelsz>>1);
- uint_t * mlocp = mloc0;
+ Elf_Rel * mrel0;
+ Elf_Rel * mrelp;
+
+ uint_t * mloc0;
+ uint_t * mlocp;
unsigned rel_entsize = 0;
unsigned symsec_sh_link = 0;
+
+ int result = 0;
+
+ totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
+ if (totrelsz == 0)
+ return 0;
+ mrel0 = umalloc(totrelsz);
+ mrelp = mrel0;
+ if (!mrel0)
+ return -1;
+
+ /* 2*sizeof(address) <= sizeof(Elf_Rel) */
+ mloc0 = umalloc(totrelsz>>1);
+ mlocp = mloc0;
+ if (!mloc0) {
+ free(mrel0);
+ return -1;
+ }
find_symtab(ehdr, shdr0, nhdr, &symtab, &symtab_shndx);
for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
char const *const txtname = has_rel_mcount(relhdr, shdr0,
shstrtab, fname);
+ if (txtname == already_has_rel_mcount) {
+ result = 0;
+ file_updated = 0;
+ goto out; /* Nothing to be done; don't append! */
+ }
if (txtname && is_mcounted_section_name(txtname)) {
+ unsigned int recsym;
uint_t recval = 0;
- unsigned const recsym = find_secsym_ndx(
- w(relhdr->sh_info), txtname, &recval,
- &shdr0[symsec_sh_link = w(relhdr->sh_link)],
- symtab, symtab_shndx,
- ehdr);
+
+ symsec_sh_link = w(relhdr->sh_link);
+ result = find_secsym_ndx(w(relhdr->sh_info), txtname,
+ &recval, &recsym,
+ &shdr0[symsec_sh_link],
+ symtab, symtab_shndx,
+ ehdr);
+ if (result)
+ goto out;
rel_entsize = _w(relhdr->sh_entsize);
mlocp = sift_rel_mcount(mlocp,
@@ -630,13 +681,17 @@
* This section is ignored by ftrace, but still
* has mcount calls. Convert them to nops now.
*/
- nop_mcount(relhdr, ehdr, txtname);
+ if (nop_mcount(relhdr, ehdr, txtname) < 0) {
+ result = -1;
+ goto out;
+ }
}
}
- if (mloc0 != mlocp) {
- append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
- rel_entsize, symsec_sh_link);
- }
+ if (!result && mloc0 != mlocp)
+ result = append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
+ rel_entsize, symsec_sh_link);
+out:
free(mrel0);
free(mloc0);
+ return result;
}
--
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