| Message ID | 20211014223234.127012-2-matheus.ferst@eldorado.org.br (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix incorrect accesses to XER | expand |
On 10/14/21 3:32 PM, matheus.ferst@eldorado.org.br wrote: > From: Matheus Ferst <matheus.ferst@eldorado.org.br> > > We should use cpu_read_xer/cpu_write_xer to save/restore the complete > register since some of its bits are in other fields of CPUPPCState. A > test is added to prevent future regressions. > > Fixes: da91a00f191f ("target-ppc: Split out SO, OV, CA fields from XER") > Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br> > --- > linux-user/ppc/signal.c | 9 +++-- > tests/tcg/ppc64/Makefile.target | 2 + > tests/tcg/ppc64le/Makefile.target | 2 + > tests/tcg/ppc64le/signal_save_restore_xer.c | 42 +++++++++++++++++++++ > 4 files changed, 52 insertions(+), 3 deletions(-) > create mode 100644 tests/tcg/ppc64le/signal_save_restore_xer.c The code is good so, Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > + sigaction(SIGILL, &sa, NULL); > + > + asm("mtspr 1, %1\n\t" > + ".long 0x0\n\t" While Appendix B does guarantee that "0" is and always will be an invalid instruction, I wonder if the test itself would be clearer (i.e. self-documenting the intent) using SIGTRAP and "trap". r~
On Thu, Oct 14, 2021 at 07:32:31PM -0300, matheus.ferst@eldorado.org.br wrote: > From: Matheus Ferst <matheus.ferst@eldorado.org.br> > > We should use cpu_read_xer/cpu_write_xer to save/restore the complete > register since some of its bits are in other fields of CPUPPCState. A > test is added to prevent future regressions. > > Fixes: da91a00f191f ("target-ppc: Split out SO, OV, CA fields from XER") > Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br> Applied to ppc-for-6.2, thanks. > --- > linux-user/ppc/signal.c | 9 +++-- > tests/tcg/ppc64/Makefile.target | 2 + > tests/tcg/ppc64le/Makefile.target | 2 + > tests/tcg/ppc64le/signal_save_restore_xer.c | 42 +++++++++++++++++++++ > 4 files changed, 52 insertions(+), 3 deletions(-) > create mode 100644 tests/tcg/ppc64le/signal_save_restore_xer.c > > diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c > index edfad28a37..4413a4a28f 100644 > --- a/linux-user/ppc/signal.c > +++ b/linux-user/ppc/signal.c > @@ -244,7 +244,7 @@ static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame) > __put_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]); > __put_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]); > __put_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]); > - __put_user(env->xer, &frame->mc_gregs[TARGET_PT_XER]); > + __put_user(cpu_read_xer(env), &frame->mc_gregs[TARGET_PT_XER]); > > for (i = 0; i < ARRAY_SIZE(env->crf); i++) { > ccr |= env->crf[i] << (32 - ((i + 1) * 4)); > @@ -319,6 +319,7 @@ static void restore_user_regs(CPUPPCState *env, > { > target_ulong save_r2 = 0; > target_ulong msr; > + target_ulong xer; > target_ulong ccr; > > int i; > @@ -334,9 +335,11 @@ static void restore_user_regs(CPUPPCState *env, > __get_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]); > __get_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]); > __get_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]); > - __get_user(env->xer, &frame->mc_gregs[TARGET_PT_XER]); > + > + __get_user(xer, &frame->mc_gregs[TARGET_PT_XER]); > + cpu_write_xer(env, xer); > + > __get_user(ccr, &frame->mc_gregs[TARGET_PT_CCR]); > - > for (i = 0; i < ARRAY_SIZE(env->crf); i++) { > env->crf[i] = (ccr >> (32 - ((i + 1) * 4))) & 0xf; > } > diff --git a/tests/tcg/ppc64/Makefile.target b/tests/tcg/ppc64/Makefile.target > index a6a4ddaeca..6ab7934fdf 100644 > --- a/tests/tcg/ppc64/Makefile.target > +++ b/tests/tcg/ppc64/Makefile.target > @@ -23,4 +23,6 @@ run-plugin-byte_reverse-with-%: > $(call skip-test, "RUN of byte_reverse ($*)", "not built") > endif > > +PPC64_TESTS += signal_save_restore_xer > + > TESTS += $(PPC64_TESTS) > diff --git a/tests/tcg/ppc64le/Makefile.target b/tests/tcg/ppc64le/Makefile.target > index c0c14ffbad..5e65b1590d 100644 > --- a/tests/tcg/ppc64le/Makefile.target > +++ b/tests/tcg/ppc64le/Makefile.target > @@ -22,4 +22,6 @@ run-plugin-byte_reverse-with-%: > $(call skip-test, "RUN of byte_reverse ($*)", "not built") > endif > > +PPC64LE_TESTS += signal_save_restore_xer > + > TESTS += $(PPC64LE_TESTS) > diff --git a/tests/tcg/ppc64le/signal_save_restore_xer.c b/tests/tcg/ppc64le/signal_save_restore_xer.c > new file mode 100644 > index 0000000000..e4f8a07dd7 > --- /dev/null > +++ b/tests/tcg/ppc64le/signal_save_restore_xer.c > @@ -0,0 +1,42 @@ > +#include <assert.h> > +#include <stdint.h> > +#include <signal.h> > +#include <sys/user.h> > + > +#define XER_SO (1 << 31) > +#define XER_OV (1 << 30) > +#define XER_CA (1 << 29) > +#define XER_OV32 (1 << 19) > +#define XER_CA32 (1 << 18) > + > +uint64_t saved; > + > +void sigill_handler(int sig, siginfo_t *si, void *ucontext) > +{ > + ucontext_t *uc = ucontext; > + uc->uc_mcontext.regs->nip += 4; > + saved = uc->uc_mcontext.regs->xer; > + uc->uc_mcontext.regs->xer |= XER_OV | XER_OV32; > +} > + > +int main(void) > +{ > + uint64_t initial = XER_CA | XER_CA32, restored; > + struct sigaction sa = { > + .sa_sigaction = sigill_handler, > + .sa_flags = SA_SIGINFO > + }; > + > + sigaction(SIGILL, &sa, NULL); > + > + asm("mtspr 1, %1\n\t" > + ".long 0x0\n\t" > + "mfspr %0, 1\n\t" > + : "=r" (restored) > + : "r" (initial)); > + > + assert(saved == initial); > + assert(restored == (XER_OV | XER_OV32 | XER_CA | XER_CA32)); > + > + return 0; > +}
On 14/10/2021 20:43, Richard Henderson wrote: > [E-MAIL EXTERNO] Não clique em links ou abra anexos, a menos que você > possa confirmar o remetente e saber que o conteúdo é seguro. Em caso de > e-mail suspeito entre imediatamente em contato com o DTI. > > On 10/14/21 3:32 PM, matheus.ferst@eldorado.org.br wrote: >> From: Matheus Ferst <matheus.ferst@eldorado.org.br> >> >> We should use cpu_read_xer/cpu_write_xer to save/restore the complete >> register since some of its bits are in other fields of CPUPPCState. A >> test is added to prevent future regressions. >> >> Fixes: da91a00f191f ("target-ppc: Split out SO, OV, CA fields from XER") >> Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br> >> --- >> linux-user/ppc/signal.c | 9 +++-- >> tests/tcg/ppc64/Makefile.target | 2 + >> tests/tcg/ppc64le/Makefile.target | 2 + >> tests/tcg/ppc64le/signal_save_restore_xer.c | 42 +++++++++++++++++++++ >> 4 files changed, 52 insertions(+), 3 deletions(-) >> create mode 100644 tests/tcg/ppc64le/signal_save_restore_xer.c > > The code is good so, > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > >> + sigaction(SIGILL, &sa, NULL); >> + >> + asm("mtspr 1, %1\n\t" >> + ".long 0x0\n\t" > > While Appendix B does guarantee that "0" is and always will be an > invalid instruction, I > wonder if the test itself would be clearer (i.e. self-documenting the > intent) using > SIGTRAP and "trap". > > > r~ It would be better, but cpu_loop is currently calling cpu_abort for POWERPC_EXCP_TRAP, so the test would fail. I'll see if I can fix that in another patch, and then we can change the test to use trap.
On 10/15/21 7:54 AM, Matheus K. Ferst wrote: >> While Appendix B does guarantee that "0" is and always will be an invalid instruction, I >> wonder if the test itself would be clearer (i.e. self-documenting the intent) using >> SIGTRAP and "trap". >> >> >> r~ > > It would be better, but cpu_loop is currently calling cpu_abort for POWERPC_EXCP_TRAP, so > the test would fail. I'll see if I can fix that in another patch, and then we can change > the test to use trap. Fair enough. r~
diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c index edfad28a37..4413a4a28f 100644 --- a/linux-user/ppc/signal.c +++ b/linux-user/ppc/signal.c @@ -244,7 +244,7 @@ static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame) __put_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]); __put_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]); __put_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]); - __put_user(env->xer, &frame->mc_gregs[TARGET_PT_XER]); + __put_user(cpu_read_xer(env), &frame->mc_gregs[TARGET_PT_XER]); for (i = 0; i < ARRAY_SIZE(env->crf); i++) { ccr |= env->crf[i] << (32 - ((i + 1) * 4)); @@ -319,6 +319,7 @@ static void restore_user_regs(CPUPPCState *env, { target_ulong save_r2 = 0; target_ulong msr; + target_ulong xer; target_ulong ccr; int i; @@ -334,9 +335,11 @@ static void restore_user_regs(CPUPPCState *env, __get_user(env->nip, &frame->mc_gregs[TARGET_PT_NIP]); __get_user(env->ctr, &frame->mc_gregs[TARGET_PT_CTR]); __get_user(env->lr, &frame->mc_gregs[TARGET_PT_LNK]); - __get_user(env->xer, &frame->mc_gregs[TARGET_PT_XER]); + + __get_user(xer, &frame->mc_gregs[TARGET_PT_XER]); + cpu_write_xer(env, xer); + __get_user(ccr, &frame->mc_gregs[TARGET_PT_CCR]); - for (i = 0; i < ARRAY_SIZE(env->crf); i++) { env->crf[i] = (ccr >> (32 - ((i + 1) * 4))) & 0xf; } diff --git a/tests/tcg/ppc64/Makefile.target b/tests/tcg/ppc64/Makefile.target index a6a4ddaeca..6ab7934fdf 100644 --- a/tests/tcg/ppc64/Makefile.target +++ b/tests/tcg/ppc64/Makefile.target @@ -23,4 +23,6 @@ run-plugin-byte_reverse-with-%: $(call skip-test, "RUN of byte_reverse ($*)", "not built") endif +PPC64_TESTS += signal_save_restore_xer + TESTS += $(PPC64_TESTS) diff --git a/tests/tcg/ppc64le/Makefile.target b/tests/tcg/ppc64le/Makefile.target index c0c14ffbad..5e65b1590d 100644 --- a/tests/tcg/ppc64le/Makefile.target +++ b/tests/tcg/ppc64le/Makefile.target @@ -22,4 +22,6 @@ run-plugin-byte_reverse-with-%: $(call skip-test, "RUN of byte_reverse ($*)", "not built") endif +PPC64LE_TESTS += signal_save_restore_xer + TESTS += $(PPC64LE_TESTS) diff --git a/tests/tcg/ppc64le/signal_save_restore_xer.c b/tests/tcg/ppc64le/signal_save_restore_xer.c new file mode 100644 index 0000000000..e4f8a07dd7 --- /dev/null +++ b/tests/tcg/ppc64le/signal_save_restore_xer.c @@ -0,0 +1,42 @@ +#include <assert.h> +#include <stdint.h> +#include <signal.h> +#include <sys/user.h> + +#define XER_SO (1 << 31) +#define XER_OV (1 << 30) +#define XER_CA (1 << 29) +#define XER_OV32 (1 << 19) +#define XER_CA32 (1 << 18) + +uint64_t saved; + +void sigill_handler(int sig, siginfo_t *si, void *ucontext) +{ + ucontext_t *uc = ucontext; + uc->uc_mcontext.regs->nip += 4; + saved = uc->uc_mcontext.regs->xer; + uc->uc_mcontext.regs->xer |= XER_OV | XER_OV32; +} + +int main(void) +{ + uint64_t initial = XER_CA | XER_CA32, restored; + struct sigaction sa = { + .sa_sigaction = sigill_handler, + .sa_flags = SA_SIGINFO + }; + + sigaction(SIGILL, &sa, NULL); + + asm("mtspr 1, %1\n\t" + ".long 0x0\n\t" + "mfspr %0, 1\n\t" + : "=r" (restored) + : "r" (initial)); + + assert(saved == initial); + assert(restored == (XER_OV | XER_OV32 | XER_CA | XER_CA32)); + + return 0; +}