RISC-V: Add support for dl_runtime_profile (BZ #31151)

Code is mostly inspired from the LoongArch one, which has a similar ABI,
with minor changes to support riscv32 and register differences.

This fixes elf/tst-sprof-basic. This also fixes elf/tst-audit1,
elf/tst-audit2 and elf/tst-audit8 with recent binutils snapshots when
--enable-bind-now is used.

Resolves: BZ #31151

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Aurelien Jarno 2023-12-30 11:00:10 +01:00
parent a8a4c94ae9
commit 6b32696116
4 changed files with 225 additions and 1 deletions

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@ -2,6 +2,10 @@ ifeq ($(subdir),misc)
sysdep_headers += sys/asm.h
endif
ifeq ($(subdir),elf)
gen-as-const-headers += dl-link.sym
endif
# RISC-V's assembler also needs to know about PIC as it changes the definition
# of some assembler macros.
ASFLAGS-.os += $(pic-ccflag)

18
sysdeps/riscv/dl-link.sym Normal file
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@ -0,0 +1,18 @@
#include <stddef.h>
#include <sysdep.h>
#include <link.h>
DL_SIZEOF_RG sizeof(struct La_riscv_regs)
DL_SIZEOF_RV sizeof(struct La_riscv_retval)
DL_OFFSET_RG_A0 offsetof(struct La_riscv_regs, lr_reg)
#ifndef __riscv_float_abi_soft
DL_OFFSET_RG_FA0 offsetof(struct La_riscv_regs, lr_fpreg)
#endif
DL_OFFSET_RG_RA offsetof(struct La_riscv_regs, lr_ra)
DL_OFFSET_RG_SP offsetof(struct La_riscv_regs, lr_sp)
DL_OFFSET_RV_A0 offsetof(struct La_riscv_retval, lrv_a0)
#ifndef __riscv_float_abi_soft
DL_OFFSET_RV_FA0 offsetof(struct La_riscv_retval, lrv_fa0)
#endif

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@ -313,13 +313,38 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
if (l->l_info[DT_JMPREL])
{
extern void _dl_runtime_resolve (void) __attribute__ ((visibility ("hidden")));
extern void _dl_runtime_profile (void) __attribute__ ((visibility ("hidden")));
ElfW(Addr) *gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
/* If a library is prelinked but we have to relocate anyway,
we have to be able to undo the prelinking of .got.plt.
The prelinker saved the address of .plt for us here. */
if (gotplt[1])
l->l_mach.plt = gotplt[1] + l->l_addr;
gotplt[0] = (ElfW(Addr)) &_dl_runtime_resolve;
/* The gotplt[0] entry contains the address of a function which gets
called to get the address of a so far unresolved function and
jump to it. The profiling extension of the dynamic linker allows
to intercept the calls to collect information. In this case we
don't store the address in the GOT so that all future calls also
end in this function. */
#ifdef SHARED
if (profile != 0)
{
gotplt[0] = (ElfW(Addr)) &_dl_runtime_profile;
if (GLRO(dl_profile) != NULL
&& _dl_name_match_p (GLRO(dl_profile), l))
/* Say that we really want profiling and the timers are
started. */
GL(dl_profile_map) = l;
}
else
#endif
{
/* This function will get called to fix up the GOT entry
indicated by the offset on the stack, and then jump to
the resolved address. */
gotplt[0] = (ElfW(Addr)) &_dl_runtime_resolve;
}
gotplt[1] = (ElfW(Addr)) l;
}

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@ -20,6 +20,8 @@
#include <sysdep.h>
#include <sys/asm.h>
#include "dl-link.h"
/* Assembler veneer called from the PLT header code for lazy loading.
The PLT header passes its own args in t0-t2. */
@ -88,3 +90,178 @@ ENTRY (_dl_runtime_resolve)
# Invoke the callee.
jr t1
END (_dl_runtime_resolve)
#if !defined PROF && defined SHARED
ENTRY (_dl_runtime_profile)
/* RISC-V we get called with:
t0 linkr_map pointer
t1 the scaled offset stored in t0, which can be used
to calculate the offset of the current symbol in .rela.plt
t2 %hi(%pcrel(.got.plt)) stored in t2, no use in this function
t3 dl resolver entry point, no use in this function
Stack frame layout with hard float:
RV64 RV32
[sp, #96] [sp, #48] La_riscv_regs
[sp, #48] [sp, #24] La_riscv_retval
[sp, #40] [sp, #20] frame size return from pltenter
[sp, #32] [sp, #16] dl_profile_call saved a1
[sp, #24] [sp, #12] dl_profile_call saved a0
[sp, #16] [sp, #8] T1
[sp, #0] [sp, #0] ra, fp <- fp
*/
# define OFFSET_T1 2*SZREG
# define OFFSET_SAVED_CALL_A0 OFFSET_T1 + SZREG
# define OFFSET_SAVED_CALL_A1 OFFSET_SAVED_CALL_A0 + SZREG
# define OFFSET_FS OFFSET_SAVED_CALL_A1 + SZREG
# define OFFSET_RV OFFSET_FS + SZREG
# define OFFSET_RG OFFSET_RV + DL_SIZEOF_RV
# define SF_SIZE (-(-(OFFSET_RG + DL_SIZEOF_RG) & ALMASK))
# Save arguments to stack.
add sp, sp, -SF_SIZE
REG_S ra, 0(sp)
REG_S fp, SZREG(sp)
mv fp, sp
REG_S a0, OFFSET_RG + DL_OFFSET_RG_A0 + 0*SZREG(fp)
REG_S a1, OFFSET_RG + DL_OFFSET_RG_A0 + 1*SZREG(fp)
REG_S a2, OFFSET_RG + DL_OFFSET_RG_A0 + 2*SZREG(fp)
REG_S a3, OFFSET_RG + DL_OFFSET_RG_A0 + 3*SZREG(fp)
REG_S a4, OFFSET_RG + DL_OFFSET_RG_A0 + 4*SZREG(fp)
REG_S a5, OFFSET_RG + DL_OFFSET_RG_A0 + 5*SZREG(fp)
REG_S a6, OFFSET_RG + DL_OFFSET_RG_A0 + 6*SZREG(fp)
REG_S a7, OFFSET_RG + DL_OFFSET_RG_A0 + 7*SZREG(fp)
#ifndef __riscv_float_abi_soft
FREG_S fa0, OFFSET_RG + DL_OFFSET_RG_FA0 + 0*SZFREG(fp)
FREG_S fa1, OFFSET_RG + DL_OFFSET_RG_FA0 + 1*SZFREG(fp)
FREG_S fa2, OFFSET_RG + DL_OFFSET_RG_FA0 + 2*SZFREG(fp)
FREG_S fa3, OFFSET_RG + DL_OFFSET_RG_FA0 + 3*SZFREG(fp)
FREG_S fa4, OFFSET_RG + DL_OFFSET_RG_FA0 + 4*SZFREG(fp)
FREG_S fa5, OFFSET_RG + DL_OFFSET_RG_FA0 + 5*SZFREG(fp)
FREG_S fa6, OFFSET_RG + DL_OFFSET_RG_FA0 + 6*SZFREG(fp)
FREG_S fa7, OFFSET_RG + DL_OFFSET_RG_FA0 + 7*SZFREG(fp)
#endif
# Update .got.plt and obtain runtime address of callee.
slli a1, t1, 1
mv a0, t0
add a1, a1, t1 # link map
mv a2, ra # return addr
addi a3, fp, OFFSET_RG # La_riscv_regs pointer
addi a4, fp, OFFSET_FS # frame size return from pltenter
REG_S a0, OFFSET_SAVED_CALL_A0(fp)
REG_S a1, OFFSET_SAVED_CALL_A1(fp)
la t2, _dl_profile_fixup
jalr t2
REG_L t3, OFFSET_FS(fp)
bgez t3, 1f
# Save the return.
mv t4, a0
# Restore arguments from stack.
REG_L a0, OFFSET_RG + DL_OFFSET_RG_A0 + 0*SZREG(fp)
REG_L a1, OFFSET_RG + DL_OFFSET_RG_A0 + 1*SZREG(fp)
REG_L a2, OFFSET_RG + DL_OFFSET_RG_A0 + 2*SZREG(fp)
REG_L a3, OFFSET_RG + DL_OFFSET_RG_A0 + 3*SZREG(fp)
REG_L a4, OFFSET_RG + DL_OFFSET_RG_A0 + 4*SZREG(fp)
REG_L a5, OFFSET_RG + DL_OFFSET_RG_A0 + 5*SZREG(fp)
REG_L a6, OFFSET_RG + DL_OFFSET_RG_A0 + 6*SZREG(fp)
REG_L a7, OFFSET_RG + DL_OFFSET_RG_A0 + 7*SZREG(fp)
#ifndef __riscv_float_abi_soft
FREG_L fa0, OFFSET_RG + DL_OFFSET_RG_FA0 + 0*SZFREG(fp)
FREG_L fa1, OFFSET_RG + DL_OFFSET_RG_FA0 + 1*SZFREG(fp)
FREG_L fa2, OFFSET_RG + DL_OFFSET_RG_FA0 + 2*SZFREG(fp)
FREG_L fa3, OFFSET_RG + DL_OFFSET_RG_FA0 + 3*SZFREG(fp)
FREG_L fa4, OFFSET_RG + DL_OFFSET_RG_FA0 + 4*SZFREG(fp)
FREG_L fa5, OFFSET_RG + DL_OFFSET_RG_FA0 + 5*SZFREG(fp)
FREG_L fa6, OFFSET_RG + DL_OFFSET_RG_FA0 + 6*SZFREG(fp)
FREG_L fa7, OFFSET_RG + DL_OFFSET_RG_FA0 + 7*SZFREG(fp)
#endif
REG_L ra, 0(fp)
REG_L fp, SZREG(fp)
addi sp, sp, SF_SIZE
jr t4
1:
# The new frame size is in t3.
sub sp, fp, t3
andi sp, sp, ALMASK
REG_S a0, OFFSET_T1(fp)
mv a0, sp
addi a1, fp, SF_SIZE
mv a2, t3
la t4, memcpy
jalr t4
REG_L t4, OFFSET_T1(fp)
# Call the function.
REG_L a0, OFFSET_RG + DL_OFFSET_RG_A0 + 0*SZREG(fp)
REG_L a1, OFFSET_RG + DL_OFFSET_RG_A0 + 1*SZREG(fp)
REG_L a2, OFFSET_RG + DL_OFFSET_RG_A0 + 2*SZREG(fp)
REG_L a3, OFFSET_RG + DL_OFFSET_RG_A0 + 3*SZREG(fp)
REG_L a4, OFFSET_RG + DL_OFFSET_RG_A0 + 4*SZREG(fp)
REG_L a5, OFFSET_RG + DL_OFFSET_RG_A0 + 5*SZREG(fp)
REG_L a6, OFFSET_RG + DL_OFFSET_RG_A0 + 6*SZREG(fp)
REG_L a7, OFFSET_RG + DL_OFFSET_RG_A0 + 7*SZREG(fp)
#ifndef __riscv_float_abi_soft
FREG_L fa0, OFFSET_RG + DL_OFFSET_RG_FA0 + 0*SZFREG(fp)
FREG_L fa1, OFFSET_RG + DL_OFFSET_RG_FA0 + 1*SZFREG(fp)
FREG_L fa2, OFFSET_RG + DL_OFFSET_RG_FA0 + 2*SZFREG(fp)
FREG_L fa3, OFFSET_RG + DL_OFFSET_RG_FA0 + 3*SZFREG(fp)
FREG_L fa4, OFFSET_RG + DL_OFFSET_RG_FA0 + 4*SZFREG(fp)
FREG_L fa5, OFFSET_RG + DL_OFFSET_RG_FA0 + 5*SZFREG(fp)
FREG_L fa6, OFFSET_RG + DL_OFFSET_RG_FA0 + 6*SZFREG(fp)
FREG_L fa7, OFFSET_RG + DL_OFFSET_RG_FA0 + 7*SZFREG(fp)
#endif
jalr t4
REG_S a0, OFFSET_SAVED_CALL_A0 + DL_OFFSET_RV_A0(fp)
REG_S a1, OFFSET_SAVED_CALL_A0 + DL_OFFSET_RV_A0 + SZREG(fp)
#ifndef __riscv_float_abi_soft
FREG_S fa0, OFFSET_SAVED_CALL_A0 + DL_OFFSET_RV_FA0(fp)
FREG_S fa1, OFFSET_SAVED_CALL_A0 + DL_OFFSET_RV_FA0 + SZFREG(fp)
#endif
# Setup call to pltexit.
REG_L a0, OFFSET_SAVED_CALL_A0(fp)
REG_L a1, OFFSET_SAVED_CALL_A0 + SZREG(fp)
addi a2, fp, OFFSET_RG
addi a3, fp, OFFSET_RV
la t4, _dl_audit_pltexit
jalr t4
REG_L a0, OFFSET_RV + DL_OFFSET_RV_A0(fp)
REG_L a1, OFFSET_RV + DL_OFFSET_RV_A0 + SZREG(fp)
#ifndef __riscv_float_abi_soft
FREG_L fa0, OFFSET_RV + DL_OFFSET_RV_FA0(fp)
FREG_L fa1, OFFSET_RV + DL_OFFSET_RV_FA0 + SZFREG(fp)
#endif
# RA from within La_riscv_reg.
REG_L ra, OFFSET_RG + DL_OFFSET_RG_RA(fp)
mv sp, fp
ADDI sp, sp, SF_SIZE
REG_S fp, SZREG(fp)
jr ra
END (_dl_runtime_profile)
#endif /* SHARED */