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Avoid APE fork bomb
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This change addresses a $PATH resolution issue where APE depends on
uname and uname is an APE program. So sorry to anyone this impacted
we'll get a release out soon.
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@jart
jart committed Nov 8, 2023
1 parent cc3e3de commit 5330442
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Showing 2 changed files with 27 additions and 24 deletions.
24 changes: 13 additions & 11 deletions ape/ape.S
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Original file line number Diff line number Diff line change
Expand Up @@ -592,7 +592,8 @@ ape_disk:

#ifdef APE_IS_SHELL_SCRIPT
apesh: .ascii "\n@\n#'\"\n" // sixth edition shebang
.ascii "m=\"$(uname -m)\"\n"
.ascii "m=\"$(/bin/uname -m >/dev/null)\" || "
.ascii "m=\"$(/usr/bin/uname -m)\"\n"

.ascii "if [ \"$m\" = x86_64 ] || [ \"$m\" = amd64 ]; then\n"
// Until all operating systems can be updated to support APE,
Expand All @@ -615,24 +616,24 @@ apesh: .ascii "\n@\n#'\"\n" // sixth edition shebang
.ascii APE_VERSION_STR
.ascii "\"\n"
.ascii "[ -x \"$t\" ] || {\n"
.ascii "mkdir -p \"${t%/*}\" &&\n"
.ascii "dd if=\"$o\" of=\"$t.$$\" skip="
.ascii "/bin/mkdir -p \"${t%/*}\" &&\n"
.ascii "/bin/dd if=\"$o\" of=\"$t.$$\" skip="
.shstub ape_loader_dd_skip,2
.ascii " count="
.shstub ape_loader_dd_count,2
.ascii " bs=64 2>/dev/null\n"
#if SupportsXnu()
.ascii "[ -d /Applications ] && "
.ascii "dd if=\"$t.$$\""
.ascii "/bin/dd if=\"$t.$$\""
.ascii " of=\"$t.$$\""
.ascii " skip=5"
.ascii " count=8"
.ascii " bs=64"
.ascii " conv=notrunc"
.ascii " 2>/dev/null\n"
#endif /* SupportsXnu() */
.ascii "chmod 755 \"$t.$$\"\n"
.ascii "mv -f \"$t.$$\" \"$t\"\n"
.ascii "/bin/chmod 755 \"$t.$$\"\n"
.ascii "/bin/mv -f \"$t.$$\" \"$t\"\n"
.ascii "}\n"
.ascii "exec \"$t\" \"$o\" \"$@\"\n"
.ascii "}\n"
Expand All @@ -648,9 +649,9 @@ apesh: .ascii "\n@\n#'\"\n" // sixth edition shebang
.ascii "t=\"${TMPDIR:-${HOME:-.}}/$0\"\n"
.ascii "[ x\"$1\" != x--assimilate ] || [ ! -e \"$t\" ] && {\n"
.ascii "[ x\"$1\" != x--assimilate ] && {\n"
.ascii "mkdir -p \"${t%/*}\" 2>/dev/null\n"
.ascii "cp -f \"$o\" \"$t.$$\" &&\n"
.ascii "mv -f \"$t.$$\" \"$t\" || exit 120\n"
.ascii "/bin/mkdir -p \"${t%/*}\" 2>/dev/null\n"
.ascii "/bin/cp -f \"$o\" \"$t.$$\" &&\n"
.ascii "/bin/mv -f \"$t.$$\" \"$t\" || exit 120\n"
.ascii "o=\"$t\"\n"
.ascii "}\n"
#endif /* APE_NO_MODIFY_SELF */
Expand Down Expand Up @@ -681,7 +682,7 @@ apesh: .ascii "\n@\n#'\"\n" // sixth edition shebang
.ascii "exec 7<&-\n"
#if SupportsXnu()
.ascii "[ -d /Applications ] && "
.ascii "dd if=\"$o\""
.ascii "/bin/dd if=\"$o\""
.ascii " of=\"$o\""
.ascii " bs=8"
.ascii " skip="
Expand Down Expand Up @@ -710,7 +711,8 @@ apesh: .ascii "\n@\n#'\"\n" // sixth edition shebang
// because they need to be in the first 4096 bytes
.section .emushprologue,"a",@progbits
emush: .ascii "\n@\n#'\"\n"
.ascii "s=\"$(uname -s)\"\n"
.ascii "s=\"$(/bin/uname -s >/dev/null)\" || "
.ascii "s=\"$(/usr/bin/uname -s)\"\n"
// our script is running on a non-x86_64 architecture
// 1. `dd` out the appropriate blink vm blob
// 2. gunzip the blink virtual machine executable
Expand Down
27 changes: 14 additions & 13 deletions tool/build/apelink.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1944,7 +1944,8 @@ int main(int argc, char *argv[]) {
}

// otherwise this is a fresh install so consider the platform
p = stpcpy(p, "m=$(uname -m)\n");
p = stpcpy(p, "m=\"$(/bin/uname -m >/dev/null)\" || "
"m=\"$(/usr/bin/uname -m)\"\n");
if (support_vector & _HOSTXNU) {
p = stpcpy(p, "if [ ! -d /Applications ]; then\n");
}
Expand Down Expand Up @@ -2044,7 +2045,7 @@ int main(int argc, char *argv[]) {
p = stpcpy(p, "if [ x\"$1\" = x--assimilate ]; then\n");
}
p = GenerateScriptIfMachine(p, in);
p = stpcpy(p, "dd if=\"$o\" of=\"$o\" bs=1");
p = stpcpy(p, "/bin/dd if=\"$o\" of=\"$o\" bs=1");
p = stpcpy(p, " skip=");
in->ddarg_macho_skip = p;
p = GenerateDecimalOffsetRelocation(p);
Expand All @@ -2070,8 +2071,8 @@ int main(int argc, char *argv[]) {
if ((loader = GetLoader(in->elf->e_machine, _HOSTXNU))) {
loader->used = true;
p = GenerateScriptIfMachine(p, in); // <if-machine>
p = stpcpy(p, "mkdir -p \"${t%/*}\" ||exit\n"
"dd if=\"$o\"");
p = stpcpy(p, "/bin/mkdir -p \"${t%/*}\" ||exit\n"
"/bin/dd if=\"$o\"");
p = stpcpy(p, " skip=");
loader->ddarg_skip1 = p;
p = GenerateDecimalOffsetRelocation(p);
Expand All @@ -2080,15 +2081,15 @@ int main(int argc, char *argv[]) {
p = GenerateDecimalOffsetRelocation(p);
p = stpcpy(p, " bs=1 2>/dev/null | gzip -dc >\"$t.$$\" ||exit\n");
if (loader->macho_offset) {
p = stpcpy(p, "dd if=\"$t.$$\" of=\"$t.$$\"");
p = stpcpy(p, "/bin/dd if=\"$t.$$\" of=\"$t.$$\"");
p = stpcpy(p, " skip=");
p = FormatInt32(p, loader->macho_offset / 64);
p = stpcpy(p, " count=");
p = FormatInt32(p, ROUNDUP(loader->macho_length, 64) / 64);
p = stpcpy(p, " bs=64 conv=notrunc 2>/dev/null ||exit\n");
}
p = stpcpy(p, "chmod 755 \"$t.$$\" ||exit\n"
"mv -f \"$t.$$\" \"$t\" ||exit\n");
p = stpcpy(p, "/bin/chmod 755 \"$t.$$\" ||exit\n"
"/bin/mv -f \"$t.$$\" \"$t\" ||exit\n");
p = stpcpy(p, "exec \"$t\" \"$o\" \"$@\"\n"
"fi\n"); // </if-machine>
gotsome = true;
Expand All @@ -2107,8 +2108,8 @@ int main(int argc, char *argv[]) {
"echo \"$0: please run: xcode-select --install\" >&2\n"
"exit 1\n"
"fi\n"
"mkdir -p \"${t%/*}\" ||exit\n"
"dd if=\"$o\"");
"/bin/mkdir -p \"${t%/*}\" ||exit\n"
"/bin/dd if=\"$o\"");
p = stpcpy(p, " skip=");
macos_silicon_loader_source_ddarg_skip = p;
p = GenerateDecimalOffsetRelocation(p);
Expand Down Expand Up @@ -2142,17 +2143,17 @@ int main(int argc, char *argv[]) {
if ((loader = GetLoader(in->elf->e_machine, ~_HOSTXNU))) {
loader->used = true;
p = GenerateScriptIfMachine(p, in);
p = stpcpy(p, "mkdir -p \"${t%/*}\" ||exit\n"
"dd if=\"$o\"");
p = stpcpy(p, "/bin/mkdir -p \"${t%/*}\" ||exit\n"
"/bin/dd if=\"$o\"");
p = stpcpy(p, " skip=");
loader->ddarg_skip2 = p;
p = GenerateDecimalOffsetRelocation(p);
p = stpcpy(p, " count=");
loader->ddarg_size2 = p;
p = GenerateDecimalOffsetRelocation(p);
p = stpcpy(p, " bs=1 2>/dev/null | gzip -dc >\"$t.$$\" ||exit\n"
"chmod 755 \"$t.$$\" ||exit\n"
"mv -f \"$t.$$\" \"$t\" ||exit\n");
"/bin/chmod 755 \"$t.$$\" ||exit\n"
"/bin/mv -f \"$t.$$\" \"$t\" ||exit\n");
p = stpcpy(p, "exec \"$t\" \"$o\" \"$@\"\n"
"fi\n");
}
Expand Down

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