[PATCH v2 07/16] MIPS: use common FP sigcontext code for O32 compat

From: Paul Burton
Date: Mon Jul 27 2015 - 16:00:55 EST


Make use of the common FP sigcontext code for O32 binaries running on
MIPS64 kernels now that it is taking appropriate offsets into struct
sigcontext(32) from struct mips_abi.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---

Changes in v2: None

arch/mips/include/asm/signal.h | 3 +
arch/mips/kernel/asm-offsets.c | 11 ---
arch/mips/kernel/r4k_fpu.S | 114 -------------------------------
arch/mips/kernel/signal.c | 4 +-
arch/mips/kernel/signal32.c | 150 ++---------------------------------------
5 files changed, 11 insertions(+), 271 deletions(-)

diff --git a/arch/mips/include/asm/signal.h b/arch/mips/include/asm/signal.h
index 8efe5a9..003e273 100644
--- a/arch/mips/include/asm/signal.h
+++ b/arch/mips/include/asm/signal.h
@@ -23,4 +23,7 @@

#define __ARCH_HAS_IRIX_SIGACTION

+extern int protected_save_fp_context(void __user *sc);
+extern int protected_restore_fp_context(void __user *sc);
+
#endif /* _ASM_SIGNAL_H */
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index beabe19..e5feff4 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -245,17 +245,6 @@ void output_sc_defines(void)
}
#endif

-#ifdef CONFIG_MIPS32_COMPAT
-void output_sc32_defines(void)
-{
- COMMENT("Linux 32-bit sigcontext offsets.");
- OFFSET(SC32_FPREGS, sigcontext32, sc_fpregs);
- OFFSET(SC32_FPC_CSR, sigcontext32, sc_fpc_csr);
- OFFSET(SC32_FPC_EIR, sigcontext32, sc_fpc_eir);
- BLANK();
-}
-#endif
-
void output_signal_defined(void)
{
COMMENT("Linux signal numbers.");
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 9e2d18d..aa11f43 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -106,66 +106,6 @@ LEAF(_save_fp_context)
.set pop
END(_save_fp_context)

-#ifdef CONFIG_MIPS32_COMPAT
- /* Save 32-bit process floating point context */
-LEAF(_save_fp_context32)
- .set push
- .set MIPS_ISA_ARCH_LEVEL_RAW
- SET_HARDFLOAT
- cfc1 t1, fcr31
-
-#ifndef CONFIG_CPU_MIPS64_R6
- mfc0 t0, CP0_STATUS
- sll t0, t0, 5
- bgez t0, 1f # skip storing odd if FR=0
- nop
-#endif
-
- /* Store the 16 odd double precision registers */
- EX sdc1 $f1, SC32_FPREGS+8(a0)
- EX sdc1 $f3, SC32_FPREGS+24(a0)
- EX sdc1 $f5, SC32_FPREGS+40(a0)
- EX sdc1 $f7, SC32_FPREGS+56(a0)
- EX sdc1 $f9, SC32_FPREGS+72(a0)
- EX sdc1 $f11, SC32_FPREGS+88(a0)
- EX sdc1 $f13, SC32_FPREGS+104(a0)
- EX sdc1 $f15, SC32_FPREGS+120(a0)
- EX sdc1 $f17, SC32_FPREGS+136(a0)
- EX sdc1 $f19, SC32_FPREGS+152(a0)
- EX sdc1 $f21, SC32_FPREGS+168(a0)
- EX sdc1 $f23, SC32_FPREGS+184(a0)
- EX sdc1 $f25, SC32_FPREGS+200(a0)
- EX sdc1 $f27, SC32_FPREGS+216(a0)
- EX sdc1 $f29, SC32_FPREGS+232(a0)
- EX sdc1 $f31, SC32_FPREGS+248(a0)
-
- /* Store the 16 even double precision registers */
-1: EX sdc1 $f0, SC32_FPREGS+0(a0)
- EX sdc1 $f2, SC32_FPREGS+16(a0)
- EX sdc1 $f4, SC32_FPREGS+32(a0)
- EX sdc1 $f6, SC32_FPREGS+48(a0)
- EX sdc1 $f8, SC32_FPREGS+64(a0)
- EX sdc1 $f10, SC32_FPREGS+80(a0)
- EX sdc1 $f12, SC32_FPREGS+96(a0)
- EX sdc1 $f14, SC32_FPREGS+112(a0)
- EX sdc1 $f16, SC32_FPREGS+128(a0)
- EX sdc1 $f18, SC32_FPREGS+144(a0)
- EX sdc1 $f20, SC32_FPREGS+160(a0)
- EX sdc1 $f22, SC32_FPREGS+176(a0)
- EX sdc1 $f24, SC32_FPREGS+192(a0)
- EX sdc1 $f26, SC32_FPREGS+208(a0)
- EX sdc1 $f28, SC32_FPREGS+224(a0)
- EX sdc1 $f30, SC32_FPREGS+240(a0)
- EX sw t1, SC32_FPC_CSR(a0)
- cfc1 t0, $0 # implementation/version
- EX sw t0, SC32_FPC_EIR(a0)
- .set pop
-
- jr ra
- li v0, 0 # success
- END(_save_fp_context32)
-#endif
-
/**
* _restore_fp_context() - restore FP context to the FPU
* @a0 - pointer to fpregs field of sigcontext
@@ -231,60 +171,6 @@ LEAF(_restore_fp_context)
li v0, 0 # success
END(_restore_fp_context)

-#ifdef CONFIG_MIPS32_COMPAT
-LEAF(_restore_fp_context32)
- /* Restore an o32 sigcontext. */
- .set push
- SET_HARDFLOAT
- EX lw t1, SC32_FPC_CSR(a0)
-
-#ifndef CONFIG_CPU_MIPS64_R6
- mfc0 t0, CP0_STATUS
- sll t0, t0, 5
- bgez t0, 1f # skip loading odd if FR=0
- nop
-#endif
-
- EX ldc1 $f1, SC32_FPREGS+8(a0)
- EX ldc1 $f3, SC32_FPREGS+24(a0)
- EX ldc1 $f5, SC32_FPREGS+40(a0)
- EX ldc1 $f7, SC32_FPREGS+56(a0)
- EX ldc1 $f9, SC32_FPREGS+72(a0)
- EX ldc1 $f11, SC32_FPREGS+88(a0)
- EX ldc1 $f13, SC32_FPREGS+104(a0)
- EX ldc1 $f15, SC32_FPREGS+120(a0)
- EX ldc1 $f17, SC32_FPREGS+136(a0)
- EX ldc1 $f19, SC32_FPREGS+152(a0)
- EX ldc1 $f21, SC32_FPREGS+168(a0)
- EX ldc1 $f23, SC32_FPREGS+184(a0)
- EX ldc1 $f25, SC32_FPREGS+200(a0)
- EX ldc1 $f27, SC32_FPREGS+216(a0)
- EX ldc1 $f29, SC32_FPREGS+232(a0)
- EX ldc1 $f31, SC32_FPREGS+248(a0)
-
-1: EX ldc1 $f0, SC32_FPREGS+0(a0)
- EX ldc1 $f2, SC32_FPREGS+16(a0)
- EX ldc1 $f4, SC32_FPREGS+32(a0)
- EX ldc1 $f6, SC32_FPREGS+48(a0)
- EX ldc1 $f8, SC32_FPREGS+64(a0)
- EX ldc1 $f10, SC32_FPREGS+80(a0)
- EX ldc1 $f12, SC32_FPREGS+96(a0)
- EX ldc1 $f14, SC32_FPREGS+112(a0)
- EX ldc1 $f16, SC32_FPREGS+128(a0)
- EX ldc1 $f18, SC32_FPREGS+144(a0)
- EX ldc1 $f20, SC32_FPREGS+160(a0)
- EX ldc1 $f22, SC32_FPREGS+176(a0)
- EX ldc1 $f24, SC32_FPREGS+192(a0)
- EX ldc1 $f26, SC32_FPREGS+208(a0)
- EX ldc1 $f28, SC32_FPREGS+224(a0)
- EX ldc1 $f30, SC32_FPREGS+240(a0)
- ctc1 t1, fcr31
- jr ra
- li v0, 0 # success
- .set pop
- END(_restore_fp_context32)
-#endif
-
.set reorder

.type fault@function
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index cc3a01f..08f5215 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -124,7 +124,7 @@ static int restore_hw_fp_context(void __user *sc)
/*
* Helper routines
*/
-static int protected_save_fp_context(void __user *sc)
+int protected_save_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
@@ -167,7 +167,7 @@ static int protected_save_fp_context(void __user *sc)
return err;
}

-static int protected_restore_fp_context(void __user *sc)
+int protected_restore_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 6b65658..2a7c6dd 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -36,12 +36,6 @@

#include "signal-common.h"

-static int (*save_fp_context32)(struct sigcontext32 __user *sc);
-static int (*restore_fp_context32)(struct sigcontext32 __user *sc);
-
-extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
-extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
-
/*
* Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
*/
@@ -74,99 +68,11 @@ struct rt_sigframe32 {
struct ucontext32 rs_uc;
};

-/*
- * Thread saved context copy to/from a signal context presumed to be on the
- * user stack, and therefore accessed with appropriate macros from uaccess.h.
- */
-static int copy_fp_to_sigcontext32(struct sigcontext32 __user *sc)
-{
- int i;
- int err = 0;
- int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
-
- for (i = 0; i < NUM_FPU_REGS; i += inc) {
- err |=
- __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
- &sc->sc_fpregs[i]);
- }
- err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
-
- return err;
-}
-
-static int copy_fp_from_sigcontext32(struct sigcontext32 __user *sc)
-{
- int i;
- int err = 0;
- int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
- u64 fpr_val;
-
- for (i = 0; i < NUM_FPU_REGS; i += inc) {
- err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
- set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
- }
- err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
-
- return err;
-}
-
-/*
- * sigcontext handlers
- */
-static int protected_save_fp_context32(struct sigcontext32 __user *sc)
-{
- int err;
- while (1) {
- lock_fpu_owner();
- if (is_fpu_owner()) {
- err = save_fp_context32(sc);
- unlock_fpu_owner();
- } else {
- unlock_fpu_owner();
- err = copy_fp_to_sigcontext32(sc);
- }
- if (likely(!err))
- break;
- /* touch the sigcontext and try again */
- err = __put_user(0, &sc->sc_fpregs[0]) |
- __put_user(0, &sc->sc_fpregs[31]) |
- __put_user(0, &sc->sc_fpc_csr);
- if (err)
- break; /* really bad sigcontext */
- }
- return err;
-}
-
-static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
-{
- int err, tmp __maybe_unused;
- while (1) {
- lock_fpu_owner();
- if (is_fpu_owner()) {
- err = restore_fp_context32(sc);
- unlock_fpu_owner();
- } else {
- unlock_fpu_owner();
- err = copy_fp_from_sigcontext32(sc);
- }
- if (likely(!err))
- break;
- /* touch the sigcontext and try again */
- err = __get_user(tmp, &sc->sc_fpregs[0]) |
- __get_user(tmp, &sc->sc_fpregs[31]) |
- __get_user(tmp, &sc->sc_fpc_csr);
- if (err)
- break; /* really bad sigcontext */
- }
- return err;
-}
-
static int setup_sigcontext32(struct pt_regs *regs,
struct sigcontext32 __user *sc)
{
int err = 0;
int i;
- u32 used_math;

err |= __put_user(regs->cp0_epc, &sc->sc_pc);

@@ -186,35 +92,18 @@ static int setup_sigcontext32(struct pt_regs *regs,
err |= __put_user(mflo3(), &sc->sc_lo3);
}

- used_math = !!used_math();
- err |= __put_user(used_math, &sc->sc_used_math);
+ /*
+ * Save FPU state to signal context. Signal handler
+ * will "inherit" current FPU state.
+ */
+ err |= protected_save_fp_context(sc);

- if (used_math) {
- /*
- * Save FPU state to signal context. Signal handler
- * will "inherit" current FPU state.
- */
- err |= protected_save_fp_context32(sc);
- }
return err;
}

-static int
-check_and_restore_fp_context32(struct sigcontext32 __user *sc)
-{
- int err, sig;
-
- err = sig = fpcsr_pending(&sc->sc_fpc_csr);
- if (err > 0)
- err = 0;
- err |= protected_restore_fp_context32(sc);
- return err ?: sig;
-}
-
static int restore_sigcontext32(struct pt_regs *regs,
struct sigcontext32 __user *sc)
{
- u32 used_math;
int err = 0;
s32 treg;
int i;
@@ -238,19 +127,7 @@ static int restore_sigcontext32(struct pt_regs *regs,
for (i = 1; i < 32; i++)
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);

- err |= __get_user(used_math, &sc->sc_used_math);
- conditional_used_math(used_math);
-
- if (used_math) {
- /* restore fpu context if we have used it before */
- if (!err)
- err = check_and_restore_fp_context32(sc);
- } else {
- /* signal handler may have used FPU. Give it up. */
- lose_fpu(0);
- }
-
- return err;
+ return err ?: protected_restore_fp_context(sc);
}

/*
@@ -593,18 +470,3 @@ struct mips_abi mips_abi_32 = {
.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
};
-
-static int signal32_init(void)
-{
- if (cpu_has_fpu) {
- save_fp_context32 = _save_fp_context32;
- restore_fp_context32 = _restore_fp_context32;
- } else {
- save_fp_context32 = copy_fp_to_sigcontext32;
- restore_fp_context32 = copy_fp_from_sigcontext32;
- }
-
- return 0;
-}
-
-arch_initcall(signal32_init);
--
2.4.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/