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From: Brian Cain <bcain@quicinc.com>
To: "Matheus Bernardino (QUIC)" <quic_mathbern@quicinc.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: Sid Manning <sidneym@quicinc.com>, "ale@rev.ng" <ale@rev.ng>,
	"anjo@rev.ng" <anjo@rev.ng>,
	"ltaylorsimpson@gmail.com" <ltaylorsimpson@gmail.com>,
	"richard.henderson@linaro.org" <richard.henderson@linaro.org>,
	Laurent Vivier <laurent@vivier.eu>
Subject: RE: [PATCH v6] Hexagon: add PC alignment check and exception
Date: Tue, 7 May 2024 23:40:15 +0000	[thread overview]
Message-ID: <CH3PR02MB10247B931B48C0CE3D3D031AAB8E42@CH3PR02MB10247.namprd02.prod.outlook.com> (raw)
In-Reply-To: <277b7aeda2c717a96d4dde936b3ac77707cb6517.1714755107.git.quic_mathbern@quicinc.com>



> -----Original Message-----
> From: Matheus Bernardino (QUIC) <quic_mathbern@quicinc.com>
> Sent: Friday, May 3, 2024 11:53 AM
> To: qemu-devel@nongnu.org
> Cc: Brian Cain <bcain@quicinc.com>; Sid Manning <sidneym@quicinc.com>;
> ale@rev.ng; anjo@rev.ng; ltaylorsimpson@gmail.com;
> richard.henderson@linaro.org; Laurent Vivier <laurent@vivier.eu>
> Subject: [PATCH v6] Hexagon: add PC alignment check and exception
> 
> The Hexagon Programmer's Reference Manual says that the exception 0x1e
> should be raised upon an unaligned program counter. Let's implement that
> and also add some tests.
> 
> Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Reviewed-by: Taylor Simpson <ltaylorsimpson@gmail.com>
> ---
> Changes in v6:
> - The multi COF test defines a new section for the unaligned label to
>   make it more robust.
> - Instead of a nop in the undesired test branch, we use a trap for
>   SYS_EXIT
> 

Reviewed-by: Brian Cain <bcain@quicinc.com>

>  target/hexagon/cpu.h              |   7 ++
>  target/hexagon/cpu_bits.h         |   4 ++
>  target/hexagon/macros.h           |   3 -
>  linux-user/hexagon/cpu_loop.c     |   4 ++
>  target/hexagon/op_helper.c        |   9 ++-
>  tests/tcg/hexagon/unaligned_pc.c  | 107 ++++++++++++++++++++++++++++++
>  tests/tcg/hexagon/Makefile.target |   2 +
>  7 files changed, 128 insertions(+), 8 deletions(-)
>  create mode 100644 tests/tcg/hexagon/unaligned_pc.c
> 
> diff --git a/target/hexagon/cpu.h b/target/hexagon/cpu.h
> index 3eef58fe8f..764f3c38cc 100644
> --- a/target/hexagon/cpu.h
> +++ b/target/hexagon/cpu.h
> @@ -134,6 +134,10 @@ struct ArchCPU {
> 
>  FIELD(TB_FLAGS, IS_TIGHT_LOOP, 0, 1)
> 
> +G_NORETURN void hexagon_raise_exception_err(CPUHexagonState *env,
> +                                            uint32_t exception,
> +                                            uintptr_t pc);
> +
>  static inline void cpu_get_tb_cpu_state(CPUHexagonState *env, vaddr *pc,
>                                          uint64_t *cs_base, uint32_t *flags)
>  {
> @@ -144,6 +148,9 @@ static inline void
> cpu_get_tb_cpu_state(CPUHexagonState *env, vaddr *pc,
>          hex_flags = FIELD_DP32(hex_flags, TB_FLAGS, IS_TIGHT_LOOP, 1);
>      }
>      *flags = hex_flags;
> +    if (*pc & PCALIGN_MASK) {
> +        hexagon_raise_exception_err(env, HEX_EXCP_PC_NOT_ALIGNED, 0);
> +    }
>  }
> 
>  typedef HexagonCPU ArchCPU;
> diff --git a/target/hexagon/cpu_bits.h b/target/hexagon/cpu_bits.h
> index 96fef71729..4279281a71 100644
> --- a/target/hexagon/cpu_bits.h
> +++ b/target/hexagon/cpu_bits.h
> @@ -20,9 +20,13 @@
> 
>  #include "qemu/bitops.h"
> 
> +#define PCALIGN 4
> +#define PCALIGN_MASK (PCALIGN - 1)
> +
>  #define HEX_EXCP_FETCH_NO_UPAGE  0x012
>  #define HEX_EXCP_INVALID_PACKET  0x015
>  #define HEX_EXCP_INVALID_OPCODE  0x015
> +#define HEX_EXCP_PC_NOT_ALIGNED  0x01e
>  #define HEX_EXCP_PRIV_NO_UREAD   0x024
>  #define HEX_EXCP_PRIV_NO_UWRITE  0x025
> 
> diff --git a/target/hexagon/macros.h b/target/hexagon/macros.h
> index 1376d6ccc1..f375471a98 100644
> --- a/target/hexagon/macros.h
> +++ b/target/hexagon/macros.h
> @@ -22,9 +22,6 @@
>  #include "hex_regs.h"
>  #include "reg_fields.h"
> 
> -#define PCALIGN 4
> -#define PCALIGN_MASK (PCALIGN - 1)
> -
>  #define GET_FIELD(FIELD, REGIN) \
>      fEXTRACTU_BITS(REGIN, reg_field_info[FIELD].width, \
>                     reg_field_info[FIELD].offset)
> diff --git a/linux-user/hexagon/cpu_loop.c b/linux-user/hexagon/cpu_loop.c
> index 7f1499ed28..d41159e52a 100644
> --- a/linux-user/hexagon/cpu_loop.c
> +++ b/linux-user/hexagon/cpu_loop.c
> @@ -60,6 +60,10 @@ void cpu_loop(CPUHexagonState *env)
>                  env->gpr[0] = ret;
>              }
>              break;
> +        case HEX_EXCP_PC_NOT_ALIGNED:
> +            force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
> +                            env->gpr[HEX_REG_R31]);
> +            break;
>          case EXCP_ATOMIC:
>              cpu_exec_step_atomic(cs);
>              break;
> diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c
> index da10ac5847..ae5a605513 100644
> --- a/target/hexagon/op_helper.c
> +++ b/target/hexagon/op_helper.c
> @@ -36,10 +36,9 @@
>  #define SF_MANTBITS    23
> 
>  /* Exceptions processing helpers */
> -static G_NORETURN
> -void do_raise_exception_err(CPUHexagonState *env,
> -                            uint32_t exception,
> -                            uintptr_t pc)
> +G_NORETURN void hexagon_raise_exception_err(CPUHexagonState *env,
> +                                            uint32_t exception,
> +                                            uintptr_t pc)
>  {
>      CPUState *cs = env_cpu(env);
>      qemu_log_mask(CPU_LOG_INT, "%s: %d\n", __func__, exception);
> @@ -49,7 +48,7 @@ void do_raise_exception_err(CPUHexagonState *env,
> 
>  G_NORETURN void HELPER(raise_exception)(CPUHexagonState *env, uint32_t
> excp)
>  {
> -    do_raise_exception_err(env, excp, 0);
> +    hexagon_raise_exception_err(env, excp, 0);
>  }
> 
>  void log_store32(CPUHexagonState *env, target_ulong addr,
> diff --git a/tests/tcg/hexagon/unaligned_pc.c
> b/tests/tcg/hexagon/unaligned_pc.c
> new file mode 100644
> index 0000000000..e9dc7cb8b5
> --- /dev/null
> +++ b/tests/tcg/hexagon/unaligned_pc.c
> @@ -0,0 +1,107 @@
> +#include <stdio.h>
> +#include <signal.h>
> +#include <setjmp.h>
> +#include <stdlib.h>
> +
> +/* will be changed in signal handler */
> +volatile sig_atomic_t completed_tests;
> +static jmp_buf after_test;
> +static int nr_tests;
> +
> +void __attribute__((naked)) test_return(void)
> +{
> +    asm volatile(
> +        "allocframe(#0x8)\n"
> +        "r0 = #0xffffffff\n"
> +        "framekey = r0\n"
> +        "dealloc_return\n"
> +        :
> +        :
> +        : "r0", "r29", "r30", "r31", "framekey");
> +}
> +
> +void test_endloop(void)
> +{
> +    asm volatile(
> +        "loop0(1f, #2)\n"
> +        "1: r0 = #0x3\n"
> +        "sa0 = r0\n"
> +        "{ nop }:endloop0\n"
> +        :
> +        :
> +        : "r0", "sa0", "lc0", "usr");
> +}
> +
> +asm(
> +    ".pushsection .text.unaligned\n"
> +    ".org 0x3\n"
> +    ".global test_multi_cof_unaligned\n"
> +    "test_multi_cof_unaligned:\n"
> +    "   jumpr r31\n"
> +    ".popsection\n"
> +);
> +
> +#define SYS_EXIT 94
> +
> +void test_multi_cof(void)
> +{
> +    asm volatile(
> +        "p0 = cmp.eq(r0, r0)\n"
> +        "{\n"
> +        "    if (p0) jump test_multi_cof_unaligned\n"
> +        "    if (!p0) jump 1f\n"
> +        "}\n"
> +        "1:"
> +        "  r0 = #1\n"
> +        "  r6 = #%0\n"
> +        "  trap0(#1)\n"
> +        :
> +        : "i"(SYS_EXIT)
> +        : "p0", "r0", "r6");
> +}
> +
> +void sigbus_handler(int signum)
> +{
> +    /* retore framekey after test_return */
> +    asm volatile(
> +        "r0 = #0\n"
> +        "framekey = r0\n"
> +        :
> +        :
> +        : "r0", "framekey");
> +    printf("Test %d complete\n", completed_tests);
> +    completed_tests++;
> +    siglongjmp(after_test, 1);
> +}
> +
> +void test_done(void)
> +{
> +    int err = (completed_tests != nr_tests);
> +    puts(err ? "FAIL" : "PASS");
> +    exit(err);
> +}
> +
> +typedef void (*test_fn)(void);
> +
> +int main()
> +{
> +    test_fn tests[] = { test_return, test_endloop, test_multi_cof, test_done };
> +    nr_tests = (sizeof(tests) / sizeof(tests[0])) - 1;
> +
> +    struct sigaction sa = {
> +        .sa_sigaction = sigbus_handler,
> +        .sa_flags = SA_SIGINFO
> +    };
> +
> +    if (sigaction(SIGBUS, &sa, NULL) < 0) {
> +        perror("sigaction");
> +        return EXIT_FAILURE;
> +    }
> +
> +    sigsetjmp(after_test, 1);
> +    tests[completed_tests]();
> +
> +    /* should never get here */
> +    puts("FAIL");
> +    return 1;
> +}
> diff --git a/tests/tcg/hexagon/Makefile.target
> b/tests/tcg/hexagon/Makefile.target
> index f839b2c0d5..e5182c01d8 100644
> --- a/tests/tcg/hexagon/Makefile.target
> +++ b/tests/tcg/hexagon/Makefile.target
> @@ -51,6 +51,7 @@ HEX_TESTS += scatter_gather
>  HEX_TESTS += hvx_misc
>  HEX_TESTS += hvx_histogram
>  HEX_TESTS += invalid-slots
> +HEX_TESTS += unaligned_pc
> 
>  run-and-check-exception = $(call run-test,$2,$3 2>$2.stderr; \
>  	test $$? -eq 1 && grep -q "exception $(strip $1)" $2.stderr)
> @@ -107,6 +108,7 @@ overflow: overflow.c hex_test.h
>  preg_alias: preg_alias.c hex_test.h
>  read_write_overlap: read_write_overlap.c hex_test.h
>  reg_mut: reg_mut.c hex_test.h
> +unaligned_pc: unaligned_pc.c
> 
>  # This test has to be compiled for the -mv67t target
>  usr: usr.c hex_test.h
> --
> 2.37.2



      reply	other threads:[~2024-05-07 23:41 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-03 16:53 [PATCH v6] Hexagon: add PC alignment check and exception Matheus Tavares Bernardino
2024-05-07 23:40 ` Brian Cain [this message]

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