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-rw-r--r--arch/powerpc/lib/Makefile3
-rw-r--r--arch/powerpc/lib/alloc.c3
-rw-r--r--arch/powerpc/lib/sstep.c114
-rw-r--r--arch/powerpc/lib/test_emulate_step.c535
-rw-r--r--arch/powerpc/lib/test_emulate_step_exec_instr.S150
5 files changed, 798 insertions, 7 deletions
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 3bf9fc6fd36c..79396e184bca 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -30,7 +30,8 @@ obj64-y += copypage_64.o copyuser_64.o mem_64.o hweight_64.o \
obj64-$(CONFIG_SMP) += locks.o
obj64-$(CONFIG_ALTIVEC) += vmx-helper.o
-obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o
+obj64-$(CONFIG_KPROBES_SANITY_TEST) += test_emulate_step.o \
+ test_emulate_step_exec_instr.o
obj-y += checksum_$(BITS).o checksum_wrappers.o \
string_$(BITS).o memcmp_$(BITS).o
diff --git a/arch/powerpc/lib/alloc.c b/arch/powerpc/lib/alloc.c
index dedf88a76f58..ce180870bd52 100644
--- a/arch/powerpc/lib/alloc.c
+++ b/arch/powerpc/lib/alloc.c
@@ -15,6 +15,9 @@ void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
p = kzalloc(size, mask);
else {
p = memblock_alloc(size, SMP_CACHE_BYTES);
+ if (!p)
+ panic("%s: Failed to allocate %zu bytes\n", __func__,
+ size);
}
return p;
}
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index d81568f783e5..3d33fb509ef4 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1169,7 +1169,7 @@ static nokprobe_inline int trap_compare(long v1, long v2)
int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
unsigned int instr)
{
- unsigned int opcode, ra, rb, rd, spr, u;
+ unsigned int opcode, ra, rb, rc, rd, spr, u;
unsigned long int imm;
unsigned long int val, val2;
unsigned int mb, me, sh;
@@ -1292,6 +1292,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
rd = (instr >> 21) & 0x1f;
ra = (instr >> 16) & 0x1f;
rb = (instr >> 11) & 0x1f;
+ rc = (instr >> 6) & 0x1f;
switch (opcode) {
#ifdef __powerpc64__
@@ -1305,6 +1306,38 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
goto trap;
return 1;
+#ifdef __powerpc64__
+ case 4:
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+
+ switch (instr & 0x3f) {
+ case 48: /* maddhd */
+ asm volatile(PPC_MADDHD(%0, %1, %2, %3) :
+ "=r" (op->val) : "r" (regs->gpr[ra]),
+ "r" (regs->gpr[rb]), "r" (regs->gpr[rc]));
+ goto compute_done;
+
+ case 49: /* maddhdu */
+ asm volatile(PPC_MADDHDU(%0, %1, %2, %3) :
+ "=r" (op->val) : "r" (regs->gpr[ra]),
+ "r" (regs->gpr[rb]), "r" (regs->gpr[rc]));
+ goto compute_done;
+
+ case 51: /* maddld */
+ asm volatile(PPC_MADDLD(%0, %1, %2, %3) :
+ "=r" (op->val) : "r" (regs->gpr[ra]),
+ "r" (regs->gpr[rb]), "r" (regs->gpr[rc]));
+ goto compute_done;
+ }
+
+ /*
+ * There are other instructions from ISA 3.0 with the same
+ * primary opcode which do not have emulation support yet.
+ */
+ return -1;
+#endif
+
case 7: /* mulli */
op->val = regs->gpr[ra] * (short) instr;
goto compute_done;
@@ -1671,10 +1704,23 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
(int) regs->gpr[rb];
goto arith_done;
-
+#ifdef __powerpc64__
+ case 265: /* modud */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ op->val = regs->gpr[ra] % regs->gpr[rb];
+ goto compute_done;
+#endif
case 266: /* add */
op->val = regs->gpr[ra] + regs->gpr[rb];
goto arith_done;
+
+ case 267: /* moduw */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ op->val = (unsigned int) regs->gpr[ra] %
+ (unsigned int) regs->gpr[rb];
+ goto compute_done;
#ifdef __powerpc64__
case 457: /* divdu */
op->val = regs->gpr[ra] / regs->gpr[rb];
@@ -1695,6 +1741,42 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
(int) regs->gpr[rb];
goto arith_done;
+ case 755: /* darn */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ switch (ra & 0x3) {
+ case 0:
+ /* 32-bit conditioned */
+ asm volatile(PPC_DARN(%0, 0) : "=r" (op->val));
+ goto compute_done;
+
+ case 1:
+ /* 64-bit conditioned */
+ asm volatile(PPC_DARN(%0, 1) : "=r" (op->val));
+ goto compute_done;
+
+ case 2:
+ /* 64-bit raw */
+ asm volatile(PPC_DARN(%0, 2) : "=r" (op->val));
+ goto compute_done;
+ }
+
+ return -1;
+#ifdef __powerpc64__
+ case 777: /* modsd */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ op->val = (long int) regs->gpr[ra] %
+ (long int) regs->gpr[rb];
+ goto compute_done;
+#endif
+ case 779: /* modsw */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ op->val = (int) regs->gpr[ra] %
+ (int) regs->gpr[rb];
+ goto compute_done;
+
/*
* Logical instructions
@@ -1765,6 +1847,20 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
do_popcnt(regs, op, regs->gpr[rd], 64);
goto logical_done_nocc;
#endif
+ case 538: /* cnttzw */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ val = (unsigned int) regs->gpr[rd];
+ op->val = (val ? __builtin_ctz(val) : 32);
+ goto logical_done;
+#ifdef __powerpc64__
+ case 570: /* cnttzd */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ val = regs->gpr[rd];
+ op->val = (val ? __builtin_ctzl(val) : 64);
+ goto logical_done;
+#endif
case 922: /* extsh */
op->val = (signed short) regs->gpr[rd];
goto logical_done;
@@ -1866,6 +1962,20 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
op->xerval &= ~XER_CA;
set_ca32(op, op->xerval & XER_CA);
goto logical_done;
+
+ case 890: /* extswsli with sh_5 = 0 */
+ case 891: /* extswsli with sh_5 = 1 */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ return -1;
+ op->type = COMPUTE + SETREG;
+ sh = rb | ((instr & 2) << 4);
+ val = (signed int) regs->gpr[rd];
+ if (sh)
+ op->val = ROTATE(val, sh) & MASK64(0, 63 - sh);
+ else
+ op->val = val;
+ goto logical_done;
+
#endif /* __powerpc64__ */
/*
diff --git a/arch/powerpc/lib/test_emulate_step.c b/arch/powerpc/lib/test_emulate_step.c
index 6c47daa61614..9992c1ea7a1d 100644
--- a/arch/powerpc/lib/test_emulate_step.c
+++ b/arch/powerpc/lib/test_emulate_step.c
@@ -1,5 +1,5 @@
/*
- * Simple sanity test for emulate_step load/store instructions.
+ * Simple sanity tests for instruction emulation infrastructure.
*
* Copyright IBM Corp. 2016
*
@@ -14,6 +14,7 @@
#include <linux/ptrace.h>
#include <asm/sstep.h>
#include <asm/ppc-opcode.h>
+#include <asm/code-patching.h>
#define IMM_L(i) ((uintptr_t)(i) & 0xffff)
@@ -48,7 +49,20 @@
___PPC_RA(a) | ___PPC_RB(b))
#define TEST_LXVD2X(s, a, b) (PPC_INST_LXVD2X | VSX_XX1((s), R##a, R##b))
#define TEST_STXVD2X(s, a, b) (PPC_INST_STXVD2X | VSX_XX1((s), R##a, R##b))
+#define TEST_ADD(t, a, b) (PPC_INST_ADD | ___PPC_RT(t) | \
+ ___PPC_RA(a) | ___PPC_RB(b))
+#define TEST_ADD_DOT(t, a, b) (PPC_INST_ADD | ___PPC_RT(t) | \
+ ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
+#define TEST_ADDC(t, a, b) (PPC_INST_ADDC | ___PPC_RT(t) | \
+ ___PPC_RA(a) | ___PPC_RB(b))
+#define TEST_ADDC_DOT(t, a, b) (PPC_INST_ADDC | ___PPC_RT(t) | \
+ ___PPC_RA(a) | ___PPC_RB(b) | 0x1)
+
+#define MAX_SUBTESTS 16
+#define IGNORE_GPR(n) (0x1UL << (n))
+#define IGNORE_XER (0x1UL << 32)
+#define IGNORE_CCR (0x1UL << 33)
static void __init init_pt_regs(struct pt_regs *regs)
{
@@ -72,9 +86,15 @@ static void __init init_pt_regs(struct pt_regs *regs)
msr_cached = true;
}
-static void __init show_result(char *ins, char *result)
+static void __init show_result(char *mnemonic, char *result)
{
- pr_info("%-14s : %s\n", ins, result);
+ pr_info("%-14s : %s\n", mnemonic, result);
+}
+
+static void __init show_result_with_descr(char *mnemonic, char *descr,
+ char *result)
+{
+ pr_info("%-14s : %-50s %s\n", mnemonic, descr, result);
}
static void __init test_ld(void)
@@ -426,7 +446,7 @@ static void __init test_lxvd2x_stxvd2x(void)
}
#endif /* CONFIG_VSX */
-static int __init test_emulate_step(void)
+static void __init run_tests_load_store(void)
{
test_ld();
test_lwz();
@@ -437,6 +457,513 @@ static int __init test_emulate_step(void)
test_lfdx_stfdx();
test_lvx_stvx();
test_lxvd2x_stxvd2x();
+}
+
+struct compute_test {
+ char *mnemonic;
+ struct {
+ char *descr;
+ unsigned long flags;
+ unsigned int instr;
+ struct pt_regs regs;
+ } subtests[MAX_SUBTESTS + 1];
+};
+
+static struct compute_test compute_tests[] = {
+ {
+ .mnemonic = "nop",
+ .subtests = {
+ {
+ .descr = "R0 = LONG_MAX",
+ .instr = PPC_INST_NOP,
+ .regs = {
+ .gpr[0] = LONG_MAX,
+ }
+ }
+ }
+ },
+ {
+ .mnemonic = "add",
+ .subtests = {
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MIN",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MIN,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = LONG_MAX, RB = LONG_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MAX,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = ULONG_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = ULONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = 0x1",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MIN",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MIN,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = INT_MAX, RB = INT_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MAX,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = UINT_MAX",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = UINT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = 0x1",
+ .instr = TEST_ADD(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = 0x1,
+ }
+ }
+ }
+ },
+ {
+ .mnemonic = "add.",
+ .subtests = {
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MIN",
+ .flags = IGNORE_CCR,
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MIN,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MAX",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = LONG_MAX, RB = LONG_MAX",
+ .flags = IGNORE_CCR,
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MAX,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = ULONG_MAX",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = ULONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = 0x1",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MIN",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MIN,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MAX",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = INT_MAX, RB = INT_MAX",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MAX,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = UINT_MAX",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = UINT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = 0x1",
+ .instr = TEST_ADD_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = 0x1,
+ }
+ }
+ }
+ },
+ {
+ .mnemonic = "addc",
+ .subtests = {
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MIN",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MIN,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = LONG_MAX, RB = LONG_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MAX,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = ULONG_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = ULONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = 0x1",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MIN",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MIN,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = INT_MAX, RB = INT_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MAX,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = UINT_MAX",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = UINT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = 0x1",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN | INT_MIN, RB = LONG_MIN | INT_MIN",
+ .instr = TEST_ADDC(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN | (uint)INT_MIN,
+ .gpr[22] = LONG_MIN | (uint)INT_MIN,
+ }
+ }
+ }
+ },
+ {
+ .mnemonic = "addc.",
+ .subtests = {
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MIN",
+ .flags = IGNORE_CCR,
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MIN,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN, RB = LONG_MAX",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = LONG_MAX, RB = LONG_MAX",
+ .flags = IGNORE_CCR,
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MAX,
+ .gpr[22] = LONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = ULONG_MAX",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = ULONG_MAX,
+ }
+ },
+ {
+ .descr = "RA = ULONG_MAX, RB = 0x1",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = ULONG_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MIN",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MIN,
+ }
+ },
+ {
+ .descr = "RA = INT_MIN, RB = INT_MAX",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MIN,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = INT_MAX, RB = INT_MAX",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = INT_MAX,
+ .gpr[22] = INT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = UINT_MAX",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = UINT_MAX,
+ }
+ },
+ {
+ .descr = "RA = UINT_MAX, RB = 0x1",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = UINT_MAX,
+ .gpr[22] = 0x1,
+ }
+ },
+ {
+ .descr = "RA = LONG_MIN | INT_MIN, RB = LONG_MIN | INT_MIN",
+ .instr = TEST_ADDC_DOT(20, 21, 22),
+ .regs = {
+ .gpr[21] = LONG_MIN | (uint)INT_MIN,
+ .gpr[22] = LONG_MIN | (uint)INT_MIN,
+ }
+ }
+ }
+ }
+};
+
+static int __init emulate_compute_instr(struct pt_regs *regs,
+ unsigned int instr)
+{
+ struct instruction_op op;
+
+ if (!regs || !instr)
+ return -EINVAL;
+
+ if (analyse_instr(&op, regs, instr) != 1 ||
+ GETTYPE(op.type) != COMPUTE) {
+ pr_info("emulation failed, instruction = 0x%08x\n", instr);
+ return -EFAULT;
+ }
+
+ emulate_update_regs(regs, &op);
+ return 0;
+}
+
+static int __init execute_compute_instr(struct pt_regs *regs,
+ unsigned int instr)
+{
+ extern int exec_instr(struct pt_regs *regs);
+ extern s32 patch__exec_instr;
+
+ if (!regs || !instr)
+ return -EINVAL;
+
+ /* Patch the NOP with the actual instruction */
+ patch_instruction_site(&patch__exec_instr, instr);
+ if (exec_instr(regs)) {
+ pr_info("execution failed, instruction = 0x%08x\n", instr);
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+#define gpr_mismatch(gprn, exp, got) \
+ pr_info("GPR%u mismatch, exp = 0x%016lx, got = 0x%016lx\n", \
+ gprn, exp, got)
+
+#define reg_mismatch(name, exp, got) \
+ pr_info("%s mismatch, exp = 0x%016lx, got = 0x%016lx\n", \
+ name, exp, got)
+
+static void __init run_tests_compute(void)
+{
+ unsigned long flags;
+ struct compute_test *test;
+ struct pt_regs *regs, exp, got;
+ unsigned int i, j, k, instr;
+ bool ignore_gpr, ignore_xer, ignore_ccr, passed;
+
+ for (i = 0; i < ARRAY_SIZE(compute_tests); i++) {
+ test = &compute_tests[i];
+
+ for (j = 0; j < MAX_SUBTESTS && test->subtests[j].descr; j++) {
+ instr = test->subtests[j].instr;
+ flags = test->subtests[j].flags;
+ regs = &test->subtests[j].regs;
+ ignore_xer = flags & IGNORE_XER;
+ ignore_ccr = flags & IGNORE_CCR;
+ passed = true;
+
+ memcpy(&exp, regs, sizeof(struct pt_regs));
+ memcpy(&got, regs, sizeof(struct pt_regs));
+
+ /*
+ * Set a compatible MSR value explicitly to ensure
+ * that XER and CR bits are updated appropriately
+ */
+ exp.msr = MSR_KERNEL;
+ got.msr = MSR_KERNEL;
+
+ if (emulate_compute_instr(&got, instr) ||
+ execute_compute_instr(&exp, instr)) {
+ passed = false;
+ goto print;
+ }
+
+ /* Verify GPR values */
+ for (k = 0; k < 32; k++) {
+ ignore_gpr = flags & IGNORE_GPR(k);
+ if (!ignore_gpr && exp.gpr[k] != got.gpr[k]) {
+ passed = false;
+ gpr_mismatch(k, exp.gpr[k], got.gpr[k]);
+ }
+ }
+
+ /* Verify LR value */
+ if (exp.link != got.link) {
+ passed = false;
+ reg_mismatch("LR", exp.link, got.link);
+ }
+
+ /* Verify XER value */
+ if (!ignore_xer && exp.xer != got.xer) {
+ passed = false;
+ reg_mismatch("XER", exp.xer, got.xer);
+ }
+
+ /* Verify CR value */
+ if (!ignore_ccr && exp.ccr != got.ccr) {
+ passed = false;
+ reg_mismatch("CR", exp.ccr, got.ccr);
+ }
+
+print:
+ show_result_with_descr(test->mnemonic,
+ test->subtests[j].descr,
+ passed ? "PASS" : "FAIL");
+ }
+ }
+}
+
+static int __init test_emulate_step(void)
+{
+ printk(KERN_INFO "Running instruction emulation self-tests ...\n");
+ run_tests_load_store();
+ run_tests_compute();
return 0;
}
diff --git a/arch/powerpc/lib/test_emulate_step_exec_instr.S b/arch/powerpc/lib/test_emulate_step_exec_instr.S
new file mode 100644
index 000000000000..1580f34f4f4f
--- /dev/null
+++ b/arch/powerpc/lib/test_emulate_step_exec_instr.S
@@ -0,0 +1,150 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Non-emulated single-stepping support (currently limited to basic integer
+ * computations) used to validate the instruction emulation infrastructure.
+ *
+ * Copyright (C) 2019 IBM Corporation
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/ppc_asm.h>
+#include <asm/code-patching-asm.h>
+#include <linux/errno.h>
+
+/* int exec_instr(struct pt_regs *regs) */
+_GLOBAL(exec_instr)
+
+ /*
+ * Stack frame layout (INT_FRAME_SIZE bytes)
+ * In-memory pt_regs (SP + STACK_FRAME_OVERHEAD)
+ * Scratch space (SP + 8)
+ * Back chain (SP + 0)
+ */
+
+ /*
+ * Allocate a new stack frame with enough space to hold the register
+ * states in an in-memory pt_regs and also create the back chain to
+ * the caller's stack frame.
+ */
+ stdu r1, -INT_FRAME_SIZE(r1)
+
+ /*
+ * Save non-volatile GPRs on stack. This includes TOC pointer (GPR2)
+ * and local variables (GPR14 to GPR31). The register for the pt_regs
+ * parameter (GPR3) is saved additionally to ensure that the resulting
+ * register state can still be saved even if GPR3 gets overwritten
+ * when loading the initial register state for the test instruction.
+ * The stack pointer (GPR1) and the thread pointer (GPR13) are not
+ * saved as these should not be modified anyway.
+ */
+ SAVE_2GPRS(2, r1)
+ SAVE_NVGPRS(r1)
+
+ /*
+ * Save LR on stack to ensure that the return address is available
+ * even if it gets overwritten by the test instruction.
+ */
+ mflr r0
+ std r0, _LINK(r1)
+
+ /*
+ * Save CR on stack. For simplicity, the entire register is saved
+ * even though only fields 2 to 4 are non-volatile.
+ */
+ mfcr r0
+ std r0, _CCR(r1)
+
+ /*
+ * Load register state for the test instruction without touching the
+ * critical non-volatile registers. The register state is passed as a
+ * pointer to a pt_regs instance.
+ */
+ subi r31, r3, GPR0
+
+ /* Load LR from pt_regs */
+ ld r0, _LINK(r31)
+ mtlr r0
+
+ /* Load CR from pt_regs */
+ ld r0, _CCR(r31)
+ mtcr r0
+
+ /* Load XER from pt_regs */
+ ld r0, _XER(r31)
+ mtxer r0
+
+ /* Load GPRs from pt_regs */
+ REST_GPR(0, r31)
+ REST_10GPRS(2, r31)
+ REST_GPR(12, r31)
+ REST_NVGPRS(r31)
+
+ /* Placeholder for the test instruction */
+1: nop
+ patch_site 1b patch__exec_instr
+
+ /*
+ * Since GPR3 is overwritten, temporarily restore it back to its
+ * original state, i.e. the pointer to pt_regs, to ensure that the
+ * resulting register state can be saved. Before doing this, a copy
+ * of it is created in the scratch space which is used later on to
+ * save it to pt_regs.
+ */
+ std r3, 8(r1)
+ REST_GPR(3, r1)
+
+ /* Save resulting GPR state to pt_regs */
+ subi r3, r3, GPR0
+ SAVE_GPR(0, r3)
+ SAVE_GPR(2, r3)
+ SAVE_8GPRS(4, r3)
+ SAVE_GPR(12, r3)
+ SAVE_NVGPRS(r3)
+
+ /* Save resulting LR to pt_regs */
+ mflr r0
+ std r0, _LINK(r3)
+
+ /* Save resulting CR to pt_regs */
+ mfcr r0
+ std r0, _CCR(r3)
+
+ /* Save resulting XER to pt_regs */
+ mfxer r0
+ std r0, _XER(r3)
+
+ /* Restore resulting GPR3 from scratch space and save it to pt_regs */
+ ld r0, 8(r1)
+ std r0, GPR3(r3)
+
+ /* Set return value to denote execution success */
+ li r3, 0
+
+ /* Continue */
+ b 3f
+
+ /* Set return value to denote execution failure */
+2: li r3, -EFAULT
+
+ /* Restore the non-volatile GPRs from stack */
+3: REST_GPR(2, r1)
+ REST_NVGPRS(r1)
+
+ /* Restore LR from stack to be able to return */
+ ld r0, _LINK(r1)
+ mtlr r0
+
+ /* Restore CR from stack */
+ ld r0, _CCR(r1)
+ mtcr r0
+
+ /* Tear down stack frame */
+ addi r1, r1, INT_FRAME_SIZE
+
+ /* Return */
+ blr
+
+ /* Setup exception table */
+ EX_TABLE(1b, 2b)
+
+_ASM_NOKPROBE_SYMBOL(exec_instr)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.