# dtrace_sdt.sh sdtinfo <c-file> <o-file> kmod
# This is used to generate DTrace SDT probe definitions for a
# kmod .o file. The output is written to <c-file>.
-# dtrace_sdt.sh sdtinfo <S-file> <o-file> <l-file>
+# dtrace_sdt.sh sdtinfo <S-file> <l-file>
# This is used to generate DTrace SDT probe definitions for a
-# kernel object file <o-file> and kernel image file <l-file>.
-# The output is written to <S-file>.
+# linked kernel image file <l-file>. The output is written to
+# <S-file>.
#
opr="$1"
fi
ofn="$1"
-lfn="$2"
+tok="$2"
if [ -z "$ofn" ]; then
echo "ERROR: Missing object file argument" > /dev/stderr
exit 1
fi
-(
- # Only include the first two objdump output runs for the actual kernel.
- # We do not need them for kernel modules.
- if [ "x${lfn}" != "x" -a "x${lfn}" != "xkmod" ]; then
- # Output all functions listed in the symbol table. Output lines will
- # all resemble the following:
- # <value> <<scope> F <section> <size> <name>
- # Therefore, output lines will contain 6 tokens (see STAGE 1 below).
- #
- ${OBJDUMP} -t ${ofn} | \
- grep ' F '
-
- # Output all functions listed in the symbol table of the linked kernel
- # image, i.e. with resolved addresses. We only output the section
- # name, value, and symbol name for these functions. Therefore, output
- # lines will contains 3 tokens (see STAGE 2 below).
- #
- # Note that we output one extra special symbol (__init_begin). This
- # one is used to signal the boundary between the init-section code
- # that gets discarded after system boot, and the general code section
- # that is used as kernel runtime. Probes in the init-section will be
- # ignored (for now).
- #
- ${OBJDUMP} -t ${lfn} | \
- awk '/ F / {
- print $4 " " $1 " " $6;
- next;
- }
-
- $NF == "__init_begin" {
- print ". " $1 " " $NF;
- }' | sort -k1,2
- else
- scripts/kmodsdt ${ofn}
- fi
+if [ "$tok" = "kmod" ]; then
+ # Pre-process the object file to handle any local functions that contain
+ # SDT probes.
+ scripts/kmodsdt ${ofn}
# Output all function symbols in the symbol table of the object file.
# Subsequently, output all relocation records for DTrace SDT probes. The
print $4 " " $1 " G " $7;
else
print $4 " " $1 " F " $6;
+ }' | \
+ sort -k1,2 | \
+ awk -v arch=${ARCH} \
+ 'function subl(v0, v1, v0h, v0l, v1h, v1l, d, tmp) {
+ tmp = $0;
+ if (length(v0) > 8) {
+ d = length(v0);
+ v0h = strtonum("0x"substr(v0, 1, d - 8));
+ v0l = strtonum("0x"substr(v0, d - 8 + 1));
+ d = length(v1);
+ v1h = strtonum("0x"substr(v1, 1, d - 8));
+ v1l = strtonum("0x"substr(v1, d - 8 + 1));
+
+ if (v0l > v1l) {
+ if (v0h >= v1h) {
+ d = sprintf("%x%x", v0h - v1h, v0l - v1l);
+ } else {
+ printf "#error Invalid addresses: %x vs %x", v0, v1 \
+ >"/dev/stderr";
+ errc++;
+ }
+ } else {
+ printf "#error Invalid addresses: %x vs %x", v0, v1 \
+ >"/dev/stderr";
+ errc++;
+ }
+ } else {
+ v0 = strtonum("0x"v0);
+ v1 = strtonum("0x"v1);
+ d = sprintf("%x", v0 - v1);
+ }
+ $0 = tmp;
+
+ return d;
+ }
+
+ BEGIN {
+ print "#include <linux/sdt.h>";
+
+ probec = 0;
+ }
+
+ #
+ # Process a symbol table definition for a function in the object
+ # file ($ofn). As we pass through the symbol table, we record the
+ # function name, address, and symbol table index or alias. This
+ # information is needed for any potential DTrace probes that may exist
+ # in the function. They will be listed in relocation records
+ # subsequent to this function definition (and are processed in the
+ # next action block).
+ #
+ NF == 4 && $3 == "F" {
+ fname = $4;
+ sub(/\..*$/, "", fname);
+ alias = $4;
+ faddr = $2;
+ sub(/^0+/, "", faddr);
+
+ next;
}
- NF > 3 && kvh {
- if (/^[0-9a-f]/) {
- sidx++;
- if ($3 == "F") {
- if ($6 == ".hidden")
- $6 = $7;
- }
- }
+
+ NF == 4 && $3 == "G" {
+ alias = $4;
+
next;
- }' | \
- sort -k1,2
-) | \
- awk -v lfn="${lfn}" \
- -v arch=${ARCH} \
- 'function addl(v0, v1, v0h, v0l, v1h, v1l, d, tmp) {
+ }
+
+ #
+ # Process a relocation record associated with the preceding function.
+ #
+ # For kernel modules:
+ # Convert the section offset into an offset in the function where the
+ # DTrace probe is located, i.e. an offset from the start of the
+ # function. This will be resolved in an absolute address at runtime
+ # when the module is loaded.
+ #
+ NF == 4 && $3 == "R" {
+ sub(/^0+/, "", $2);
+
+ addr = subl($2, faddr);
+
+ if (arch == "x86" || arch == "x86_64")
+ addr = subl(addr, 1);
+
+ protom[alias] = 1;
+ probev[probec] = sprintf(" {\042%s\042, \042%s\042 /* %s */, (uintptr_t)%s+0x%s },", $4, fname, $1, alias, addr);
+ probec++;
+
+ next;
+ }
+
+ END {
+ if (probec > 0) {
+ for (alias in protom)
+ printf "extern void %s(void);\n", alias;
+ print "\nstatic sdt_probedesc_t\t_sdt_probes[] = {";
+ for (i = 0; i < probec; i++)
+ print probev[i];
+ print "};\n";
+ } else
+ print "#define _sdt_probes\tNULL";
+
+ print "#define _sdt_probec\t" probec;
+
+ exit(errc == 0 ? 0 : 1);
+ }' > $tfn
+else
+ # For a linked kernel (with relocation data), the scope of DTrace SDT
+ # probe discovery can be limited to just the .text section.
+ #
+ # First the section record is retrieved in order to determine the base
+ # address for symbols in the .text section.
+ #
+ # Subsequently, all function symbols that are located in the .text sectio
+ # are read from the symbol table of the linked kernel object. Each symbol
+ # is reported in the output stream with its address, a token identifying it
+ # as a function (or alias), and its name.
+ #
+ # Finally, each relocation record from the .text section that relates to
+ # SDT probes are written to the output stream with its address, a token
+ # identifying it as a relocation, and its name. Probes are identified in
+ # the relocation records as symbols with __dtrace_probe_ as prefix.
+ #
+ # We sort the output based on the address, which guarantees that the output
+ # will be a list of functions, and each function record will be followed
+ # immediately by any DTrace SDT probe records that are used in that
+ # function.
+ #
+ # Three different record types can show up in the output (3 tokens each):
+ # <address> F <name>
+ # Named function at a specific address.
+ # <address> G <name>
+ # Global alias for a local function at a specific offset. A
+ # function can only have one alias, and there cannot be an alias
+ # without its respective function.
+ # <address> R <value>
+ # Relocation within a section at a specific address
+ #
+ ${OBJDUMP} -htrj .text ${ofn} | \
+ awk 'function addl(v0, v1, v0h, v0l, v1h, v1l, d, tmp) {
tmp = $0;
if (length(v0) > 8 || length(v1) > 8) {
d = length(v0);
return d;
}
- function subl(v0, v1, v0h, v0l, v1h, v1l, d, tmp) {
+ NF == 7 && $2 == ".text" {
+ base = $4;
+ next;
+ }
+
+ /^RELOC/ {
+ in_reloc = $4 == "[.text]:";
+ next;
+ }
+
+ in_reloc && /__dtrace_probe_/ {
+ $3 = substr($3, 16);
+ sub(/[\-+].*$/, "", $3);
+ print addl(base, $1) " R " $3;
+ next;
+ }
+
+ / F / {
+ if ($6 == ".hidden")
+ print $1 " G " $7;
+ else
+ print $1 " F " $6;
+ }' | \
+ sort -k1,2 | \
+ awk -v arch=${ARCH} \
+ 'function subl(v0, v1, v0h, v0l, v1h, v1l, d, tmp) {
tmp = $0;
if (length(v0) > 8) {
d = length(v0);
}
BEGIN {
- if (lfn != "kmod") {
- print "#include <asm/types.h>";
- print "#if BITS_PER_LONG == 64";
- print "# define PTR .quad";
- print "# define ALGN .align 8";
- print "#else";
- print "# define PTR .long";
- print "# define ALGN .align 4";
- print "#endif";
-
- print "\t.section .rodata, \042a\042";
- print "";
-
- print ".globl dtrace_sdt_probes";
- print "\tALGN";
- print "dtrace_sdt_probes:";
- } else
- print "#include <linux/sdt.h>";
+ print "#include <asm/types.h>";
+ print "#if BITS_PER_LONG == 64";
+ print "# define PTR .quad";
+ print "# define ALGN .align 8";
+ print "#else";
+ print "# define PTR .long";
+ print "# define ALGN .align 4";
+ print "#endif";
+
+ print "\t.section .rodata, \042a\042";
+ print "";
+
+ print ".globl dtrace_sdt_probes";
+ print "\tALGN";
+ print "dtrace_sdt_probes:";
probec = 0;
}
#
- # [STAGE 1] Kernel only:
- # Process a symbol table definition for a function in the object
- # file ($ofn). As we pass through the symbol table, we record the
- # function with the lowest offset within each section.
- #
- NF == 6 {
- if ($4 in sectaddr) {
- if ($1 < sectaddr[$4]) {
- sectaddr[$4] = $1;
- sectfunc[$4] = $6;
- }
- } else {
- secttodo[$4] = 1;
- sectaddr[$4] = $1;
- sectfunc[$4] = $6;
- }
-
- next;
- }
-
- #
- # [STAGE 2] Kernel only:
- # Process a symbol table definition for a function in the final link
- # target ($tfn). As we pass through the symbol table, we update the
- # section data with the final load address using the known function
- # with lowest offset wihin the section.
- #
- NF == 3 { # Symbol def in $lfn (final addresses)
- for (s in secttodo) {
- if (sectfunc[s] == $3) {
- if (init_begin && $2 > init_begin) {
- sectname[s] = "";
- next;
- }
-
- sectname[s] = $1;
-
- # If the first function in the section is not at offset 0,
- # subtracting the offset from the function address yields
- # the address of the start of the section.
- if (sectaddr[s] !~ /^0+$/)
- sectaddr[s] = subl($2, sectaddr[s]);
- else
- sectaddr[s] = $2;
-
- delete secttodo[s];
-
- next;
- }
- }
-
- if ($3 == "__init_begin") {
- print "\t/* Sections above " $2 " are skipped. */";
- init_begin = $2;
- }
-
- next;
- }
-
- #
- # [STAGE 3a] Kernel and kernel modules:
- # Process a symbol table definition for a function in the object
- # file ($ofn). As we pass through the symbol table, we record the
- # function name, address, and symbol table index or alias. This
- # information is needed for any potential DTrace probes that may exist
- # in the function. They will be listed in relocation records
- # subsequent to this function definition (and are processed in the
- # next action block).
+ # Process a symbol table definition for a function in the .text
+ # section of the kernel image. As we pass through the symbol table,
+ # we record the function name and address.
#
- NF == 4 && $3 == "F" {
- fname = $4;
+ NF == 3 && $2 == "F" {
+ fname = $3;
sub(/\..*$/, "", fname);
- alias = $4;
- faddr = $2;
- sub(/^0+/, "", faddr);
+ alias = $3;
next;
}
- NF == 4 && $3 == "G" {
- alias = $4;
+ NF == 3 && $2 == "G" {
+ alias = $3;
next;
}
#
- # [STAGE 3b] Kernel and kernel modules:
# Process a relocation record associated with the preceding function.
#
- # For kernel:
- # Convert the section offset into an absolute address based on the
- # section load address.
- #
- # For kernel modules:
- # Convert the section offset into an offset in the function where the
- # DTrace probe is located, i.e. an offset from the start of the
- # function. This will be resolved in an absolute address at runtime
- # when the module is loaded.
+ # Since all addresses are already resolved earlier, we can simply
+ # generate the SDT probe information record.
#
- NF == 4 && $3 == "R" {
- sub(/^0+/, "", $2);
+ NF == 3 && $2 == "R" {
+ sub(/^0+/, "", $1);
+
+ addr = $1;
- if (lfn != "kmod") {
- if ($1 in sectaddr) {
- if (!sectname[$1]) {
- printf "WARNING: Probe %s in [%s] %s() ignored - " \
- "init-section.\n", $4, $1, fname \
- >"/dev/stderr";
- next;
- }
-
- addr = addl(sectaddr[$1], $2);
- printf "\t/* [%s base] %s + %s = [%s] %s */\n", \
- $1, sectaddr[$1], $2, sectname[$1], addr \
- } else
- addr = $2;
-
- if (arch == "x86" || arch == "x86_64")
- addr = subl(addr, 1);
-
- printf "\tPTR\t0x%s\n", addr;
- printf "\tPTR\t%d\n", length($4);
- printf "\tPTR\t%d\n", length(fname);
- printf "\t.asciz\t\042%s\042\n", $4;
- printf "\t.asciz\t\042%s\042\n", fname;
- print "\tALGN";
- } else {
- addr = subl($2, faddr);
-
- if (arch == "x86" || arch == "x86_64")
- addr = subl(addr, 1);
-
- protom[alias] = 1;
- probev[probec] = sprintf(" {\042%s\042, \042%s\042 /* %s */, (uintptr_t)%s+0x%s },", $4, fname, $1, alias, addr);
- }
+ if (arch == "x86" || arch == "x86_64")
+ addr = subl(addr, 1);
+
+ printf "\tPTR\t0x%s\n", addr;
+ printf "\tPTR\t%d\n", length($3);
+ printf "\tPTR\t%d\n", length(fname);
+ printf "\t.asciz\t\042%s\042\n", $3;
+ printf "\t.asciz\t\042%s\042\n", fname;
+ print "\tALGN";
probec++;
}
END {
- if (lfn != "kmod") {
- print "";
- print ".globl dtrace_sdt_nprobes";
- print "\tALGN";
- print "dtrace_sdt_nprobes:";
- printf "\tPTR\t%d\n", probec;
- } else {
- if (probec > 0) {
- for (alias in protom)
- printf "extern void %s(void);\n", alias;
- print "\nstatic sdt_probedesc_t\t_sdt_probes[] = {";
- for (i = 0; i < probec; i++)
- print probev[i];
- print "};\n";
- } else
- print "#define _sdt_probes\tNULL";
-
- print "#define _sdt_probec\t" probec;
- }
+ print "";
+ print ".globl dtrace_sdt_nprobes";
+ print "\tALGN";
+ print "dtrace_sdt_nprobes:";
+ printf "\tPTR\t%d\n", probec;
exit(errc == 0 ? 0 : 1);
}' > $tfn
+fi
exit $?
projects / users / jedix / linux-maple.git / commitdiff