diff options
Diffstat (limited to 'arch/ia64/kernel/unwind.c')
-rw-r--r-- | arch/ia64/kernel/unwind.c | 2320 |
1 files changed, 2320 insertions, 0 deletions
diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c new file mode 100644 index 0000000000..6bd64c35e6 --- /dev/null +++ b/arch/ia64/kernel/unwind.c @@ -0,0 +1,2320 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 1999-2004 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * Copyright (C) 2003 Fenghua Yu <fenghua.yu@intel.com> + * - Change pt_regs_off() to make it less dependent on pt_regs structure. + */ +/* + * This file implements call frame unwind support for the Linux + * kernel. Parsing and processing the unwind information is + * time-consuming, so this implementation translates the unwind + * descriptors into unwind scripts. These scripts are very simple + * (basically a sequence of assignments) and efficient to execute. + * They are cached for later re-use. Each script is specific for a + * given instruction pointer address and the set of predicate values + * that the script depends on (most unwind descriptors are + * unconditional and scripts often do not depend on predicates at + * all). This code is based on the unwind conventions described in + * the "IA-64 Software Conventions and Runtime Architecture" manual. + * + * SMP conventions: + * o updates to the global unwind data (in structure "unw") are serialized + * by the unw.lock spinlock + * o each unwind script has its own read-write lock; a thread must acquire + * a read lock before executing a script and must acquire a write lock + * before modifying a script + * o if both the unw.lock spinlock and a script's read-write lock must be + * acquired, then the read-write lock must be acquired first. + */ +#include <linux/module.h> +#include <linux/memblock.h> +#include <linux/elf.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <asm/unwind.h> + +#include <asm/delay.h> +#include <asm/page.h> +#include <asm/ptrace.h> +#include <asm/ptrace_offsets.h> +#include <asm/rse.h> +#include <asm/sections.h> +#include <linux/uaccess.h> + +#include "entry.h" +#include "unwind_i.h" + +#define UNW_LOG_CACHE_SIZE 7 /* each unw_script is ~256 bytes in size */ +#define UNW_CACHE_SIZE (1 << UNW_LOG_CACHE_SIZE) + +#define UNW_LOG_HASH_SIZE (UNW_LOG_CACHE_SIZE + 1) +#define UNW_HASH_SIZE (1 << UNW_LOG_HASH_SIZE) + +#define UNW_STATS 0 /* WARNING: this disabled interrupts for long time-spans!! */ + +#ifdef UNW_DEBUG + static unsigned int unw_debug_level = UNW_DEBUG; +# define UNW_DEBUG_ON(n) unw_debug_level >= n + /* Do not code a printk level, not all debug lines end in newline */ +# define UNW_DPRINT(n, ...) if (UNW_DEBUG_ON(n)) printk(__VA_ARGS__) +# undef inline +# define inline +#else /* !UNW_DEBUG */ +# define UNW_DEBUG_ON(n) 0 +# define UNW_DPRINT(n, ...) +#endif /* UNW_DEBUG */ + +#if UNW_STATS +# define STAT(x...) x +#else +# define STAT(x...) +#endif + +#define alloc_reg_state() kmalloc(sizeof(struct unw_reg_state), GFP_ATOMIC) +#define free_reg_state(usr) kfree(usr) +#define alloc_labeled_state() kmalloc(sizeof(struct unw_labeled_state), GFP_ATOMIC) +#define free_labeled_state(usr) kfree(usr) + +typedef unsigned long unw_word; +typedef unsigned char unw_hash_index_t; + +static struct { + spinlock_t lock; /* spinlock for unwind data */ + + /* list of unwind tables (one per load-module) */ + struct unw_table *tables; + + unsigned long r0; /* constant 0 for r0 */ + + /* table of registers that prologues can save (and order in which they're saved): */ + const unsigned char save_order[8]; + + /* maps a preserved register index (preg_index) to corresponding switch_stack offset: */ + unsigned short sw_off[sizeof(struct unw_frame_info) / 8]; + + unsigned short lru_head; /* index of lead-recently used script */ + unsigned short lru_tail; /* index of most-recently used script */ + + /* index into unw_frame_info for preserved register i */ + unsigned short preg_index[UNW_NUM_REGS]; + + short pt_regs_offsets[32]; + + /* unwind table for the kernel: */ + struct unw_table kernel_table; + + /* unwind table describing the gate page (kernel code that is mapped into user space): */ + size_t gate_table_size; + unsigned long *gate_table; + + /* hash table that maps instruction pointer to script index: */ + unsigned short hash[UNW_HASH_SIZE]; + + /* script cache: */ + struct unw_script cache[UNW_CACHE_SIZE]; + +# ifdef UNW_DEBUG + const char *preg_name[UNW_NUM_REGS]; +# endif +# if UNW_STATS + struct { + struct { + int lookups; + int hinted_hits; + int normal_hits; + int collision_chain_traversals; + } cache; + struct { + unsigned long build_time; + unsigned long run_time; + unsigned long parse_time; + int builds; + int news; + int collisions; + int runs; + } script; + struct { + unsigned long init_time; + unsigned long unwind_time; + int inits; + int unwinds; + } api; + } stat; +# endif +} unw = { + .tables = &unw.kernel_table, + .lock = __SPIN_LOCK_UNLOCKED(unw.lock), + .save_order = { + UNW_REG_RP, UNW_REG_PFS, UNW_REG_PSP, UNW_REG_PR, + UNW_REG_UNAT, UNW_REG_LC, UNW_REG_FPSR, UNW_REG_PRI_UNAT_GR + }, + .preg_index = { + offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_GR */ + offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_MEM */ + offsetof(struct unw_frame_info, bsp_loc)/8, + offsetof(struct unw_frame_info, bspstore_loc)/8, + offsetof(struct unw_frame_info, pfs_loc)/8, + offsetof(struct unw_frame_info, rnat_loc)/8, + offsetof(struct unw_frame_info, psp)/8, + offsetof(struct unw_frame_info, rp_loc)/8, + offsetof(struct unw_frame_info, r4)/8, + offsetof(struct unw_frame_info, r5)/8, + offsetof(struct unw_frame_info, r6)/8, + offsetof(struct unw_frame_info, r7)/8, + offsetof(struct unw_frame_info, unat_loc)/8, + offsetof(struct unw_frame_info, pr_loc)/8, + offsetof(struct unw_frame_info, lc_loc)/8, + offsetof(struct unw_frame_info, fpsr_loc)/8, + offsetof(struct unw_frame_info, b1_loc)/8, + offsetof(struct unw_frame_info, b2_loc)/8, + offsetof(struct unw_frame_info, b3_loc)/8, + offsetof(struct unw_frame_info, b4_loc)/8, + offsetof(struct unw_frame_info, b5_loc)/8, + offsetof(struct unw_frame_info, f2_loc)/8, + offsetof(struct unw_frame_info, f3_loc)/8, + offsetof(struct unw_frame_info, f4_loc)/8, + offsetof(struct unw_frame_info, f5_loc)/8, + offsetof(struct unw_frame_info, fr_loc[16 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[17 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[18 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[19 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[20 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[21 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[22 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[23 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[24 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[25 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[26 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[27 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[28 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[29 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[30 - 16])/8, + offsetof(struct unw_frame_info, fr_loc[31 - 16])/8, + }, + .pt_regs_offsets = { + [0] = -1, + offsetof(struct pt_regs, r1), + offsetof(struct pt_regs, r2), + offsetof(struct pt_regs, r3), + [4] = -1, [5] = -1, [6] = -1, [7] = -1, + offsetof(struct pt_regs, r8), + offsetof(struct pt_regs, r9), + offsetof(struct pt_regs, r10), + offsetof(struct pt_regs, r11), + offsetof(struct pt_regs, r12), + offsetof(struct pt_regs, r13), + offsetof(struct pt_regs, r14), + offsetof(struct pt_regs, r15), + offsetof(struct pt_regs, r16), + offsetof(struct pt_regs, r17), + offsetof(struct pt_regs, r18), + offsetof(struct pt_regs, r19), + offsetof(struct pt_regs, r20), + offsetof(struct pt_regs, r21), + offsetof(struct pt_regs, r22), + offsetof(struct pt_regs, r23), + offsetof(struct pt_regs, r24), + offsetof(struct pt_regs, r25), + offsetof(struct pt_regs, r26), + offsetof(struct pt_regs, r27), + offsetof(struct pt_regs, r28), + offsetof(struct pt_regs, r29), + offsetof(struct pt_regs, r30), + offsetof(struct pt_regs, r31), + }, + .hash = { [0 ... UNW_HASH_SIZE - 1] = -1 }, +#ifdef UNW_DEBUG + .preg_name = { + "pri_unat_gr", "pri_unat_mem", "bsp", "bspstore", "ar.pfs", "ar.rnat", "psp", "rp", + "r4", "r5", "r6", "r7", + "ar.unat", "pr", "ar.lc", "ar.fpsr", + "b1", "b2", "b3", "b4", "b5", + "f2", "f3", "f4", "f5", + "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", + "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31" + } +#endif +}; + +static inline int +read_only (void *addr) +{ + return (unsigned long) ((char *) addr - (char *) &unw.r0) < sizeof(unw.r0); +} + +/* + * Returns offset of rREG in struct pt_regs. + */ +static inline unsigned long +pt_regs_off (unsigned long reg) +{ + short off = -1; + + if (reg < ARRAY_SIZE(unw.pt_regs_offsets)) + off = unw.pt_regs_offsets[reg]; + + if (off < 0) { + UNW_DPRINT(0, "unwind.%s: bad scratch reg r%lu\n", __func__, reg); + off = 0; + } + return (unsigned long) off; +} + +static inline struct pt_regs * +get_scratch_regs (struct unw_frame_info *info) +{ + if (!info->pt) { + /* This should not happen with valid unwind info. */ + UNW_DPRINT(0, "unwind.%s: bad unwind info: resetting info->pt\n", __func__); + if (info->flags & UNW_FLAG_INTERRUPT_FRAME) + info->pt = (unsigned long) ((struct pt_regs *) info->psp - 1); + else + info->pt = info->sp - 16; + } + UNW_DPRINT(3, "unwind.%s: sp 0x%lx pt 0x%lx\n", __func__, info->sp, info->pt); + return (struct pt_regs *) info->pt; +} + +/* Unwind accessors. */ + +int +unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char *nat, int write) +{ + unsigned long *addr, *nat_addr, nat_mask = 0, dummy_nat; + struct unw_ireg *ireg; + struct pt_regs *pt; + + if ((unsigned) regnum - 1 >= 127) { + if (regnum == 0 && !write) { + *val = 0; /* read r0 always returns 0 */ + *nat = 0; + return 0; + } + UNW_DPRINT(0, "unwind.%s: trying to access non-existent r%u\n", + __func__, regnum); + return -1; + } + + if (regnum < 32) { + if (regnum >= 4 && regnum <= 7) { + /* access a preserved register */ + ireg = &info->r4 + (regnum - 4); + addr = ireg->loc; + if (addr) { + nat_addr = addr + ireg->nat.off; + switch (ireg->nat.type) { + case UNW_NAT_VAL: + /* simulate getf.sig/setf.sig */ + if (write) { + if (*nat) { + /* write NaTVal and be done with it */ + addr[0] = 0; + addr[1] = 0x1fffe; + return 0; + } + addr[1] = 0x1003e; + } else { + if (addr[0] == 0 && addr[1] == 0x1ffe) { + /* return NaT and be done with it */ + *val = 0; + *nat = 1; + return 0; + } + } + fallthrough; + case UNW_NAT_NONE: + dummy_nat = 0; + nat_addr = &dummy_nat; + break; + + case UNW_NAT_MEMSTK: + nat_mask = (1UL << ((long) addr & 0x1f8)/8); + break; + + case UNW_NAT_REGSTK: + nat_addr = ia64_rse_rnat_addr(addr); + if ((unsigned long) addr < info->regstk.limit + || (unsigned long) addr >= info->regstk.top) + { + UNW_DPRINT(0, "unwind.%s: %p outside of regstk " + "[0x%lx-0x%lx)\n", + __func__, (void *) addr, + info->regstk.limit, + info->regstk.top); + return -1; + } + if ((unsigned long) nat_addr >= info->regstk.top) + nat_addr = &info->sw->ar_rnat; + nat_mask = (1UL << ia64_rse_slot_num(addr)); + break; + } + } else { + addr = &info->sw->r4 + (regnum - 4); + nat_addr = &info->sw->ar_unat; + nat_mask = (1UL << ((long) addr & 0x1f8)/8); + } + } else { + /* access a scratch register */ + pt = get_scratch_regs(info); + addr = (unsigned long *) ((unsigned long)pt + pt_regs_off(regnum)); + if (info->pri_unat_loc) + nat_addr = info->pri_unat_loc; + else + nat_addr = &info->sw->caller_unat; + nat_mask = (1UL << ((long) addr & 0x1f8)/8); + } + } else { + /* access a stacked register */ + addr = ia64_rse_skip_regs((unsigned long *) info->bsp, regnum - 32); + nat_addr = ia64_rse_rnat_addr(addr); + if ((unsigned long) addr < info->regstk.limit + || (unsigned long) addr >= info->regstk.top) + { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to access register outside " + "of rbs\n", __func__); + return -1; + } + if ((unsigned long) nat_addr >= info->regstk.top) + nat_addr = &info->sw->ar_rnat; + nat_mask = (1UL << ia64_rse_slot_num(addr)); + } + + if (write) { + if (read_only(addr)) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n", + __func__); + } else { + *addr = *val; + if (*nat) + *nat_addr |= nat_mask; + else + *nat_addr &= ~nat_mask; + } + } else { + if ((*nat_addr & nat_mask) == 0) { + *val = *addr; + *nat = 0; + } else { + *val = 0; /* if register is a NaT, *addr may contain kernel data! */ + *nat = 1; + } + } + return 0; +} +EXPORT_SYMBOL(unw_access_gr); + +int +unw_access_br (struct unw_frame_info *info, int regnum, unsigned long *val, int write) +{ + unsigned long *addr; + struct pt_regs *pt; + + switch (regnum) { + /* scratch: */ + case 0: pt = get_scratch_regs(info); addr = &pt->b0; break; + case 6: pt = get_scratch_regs(info); addr = &pt->b6; break; + case 7: pt = get_scratch_regs(info); addr = &pt->b7; break; + + /* preserved: */ + case 1: case 2: case 3: case 4: case 5: + addr = *(&info->b1_loc + (regnum - 1)); + if (!addr) + addr = &info->sw->b1 + (regnum - 1); + break; + + default: + UNW_DPRINT(0, "unwind.%s: trying to access non-existent b%u\n", + __func__, regnum); + return -1; + } + if (write) + if (read_only(addr)) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n", + __func__); + } else + *addr = *val; + else + *val = *addr; + return 0; +} +EXPORT_SYMBOL(unw_access_br); + +int +unw_access_fr (struct unw_frame_info *info, int regnum, struct ia64_fpreg *val, int write) +{ + struct ia64_fpreg *addr = NULL; + struct pt_regs *pt; + + if ((unsigned) (regnum - 2) >= 126) { + UNW_DPRINT(0, "unwind.%s: trying to access non-existent f%u\n", + __func__, regnum); + return -1; + } + + if (regnum <= 5) { + addr = *(&info->f2_loc + (regnum - 2)); + if (!addr) + addr = &info->sw->f2 + (regnum - 2); + } else if (regnum <= 15) { + if (regnum <= 11) { + pt = get_scratch_regs(info); + addr = &pt->f6 + (regnum - 6); + } + else + addr = &info->sw->f12 + (regnum - 12); + } else if (regnum <= 31) { + addr = info->fr_loc[regnum - 16]; + if (!addr) + addr = &info->sw->f16 + (regnum - 16); + } else { + struct task_struct *t = info->task; + + if (write) + ia64_sync_fph(t); + else + ia64_flush_fph(t); + addr = t->thread.fph + (regnum - 32); + } + + if (write) + if (read_only(addr)) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n", + __func__); + } else + *addr = *val; + else + *val = *addr; + return 0; +} +EXPORT_SYMBOL(unw_access_fr); + +int +unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, int write) +{ + unsigned long *addr; + struct pt_regs *pt; + + switch (regnum) { + case UNW_AR_BSP: + addr = info->bsp_loc; + if (!addr) + addr = &info->sw->ar_bspstore; + break; + + case UNW_AR_BSPSTORE: + addr = info->bspstore_loc; + if (!addr) + addr = &info->sw->ar_bspstore; + break; + + case UNW_AR_PFS: + addr = info->pfs_loc; + if (!addr) + addr = &info->sw->ar_pfs; + break; + + case UNW_AR_RNAT: + addr = info->rnat_loc; + if (!addr) + addr = &info->sw->ar_rnat; + break; + + case UNW_AR_UNAT: + addr = info->unat_loc; + if (!addr) + addr = &info->sw->caller_unat; + break; + + case UNW_AR_LC: + addr = info->lc_loc; + if (!addr) + addr = &info->sw->ar_lc; + break; + + case UNW_AR_EC: + if (!info->cfm_loc) + return -1; + if (write) + *info->cfm_loc = + (*info->cfm_loc & ~(0x3fUL << 52)) | ((*val & 0x3f) << 52); + else + *val = (*info->cfm_loc >> 52) & 0x3f; + return 0; + + case UNW_AR_FPSR: + addr = info->fpsr_loc; + if (!addr) + addr = &info->sw->ar_fpsr; + break; + + case UNW_AR_RSC: + pt = get_scratch_regs(info); + addr = &pt->ar_rsc; + break; + + case UNW_AR_CCV: + pt = get_scratch_regs(info); + addr = &pt->ar_ccv; + break; + + case UNW_AR_CSD: + pt = get_scratch_regs(info); + addr = &pt->ar_csd; + break; + + case UNW_AR_SSD: + pt = get_scratch_regs(info); + addr = &pt->ar_ssd; + break; + + default: + UNW_DPRINT(0, "unwind.%s: trying to access non-existent ar%u\n", + __func__, regnum); + return -1; + } + + if (write) { + if (read_only(addr)) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n", + __func__); + } else + *addr = *val; + } else + *val = *addr; + return 0; +} +EXPORT_SYMBOL(unw_access_ar); + +int +unw_access_pr (struct unw_frame_info *info, unsigned long *val, int write) +{ + unsigned long *addr; + + addr = info->pr_loc; + if (!addr) + addr = &info->sw->pr; + + if (write) { + if (read_only(addr)) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n", + __func__); + } else + *addr = *val; + } else + *val = *addr; + return 0; +} +EXPORT_SYMBOL(unw_access_pr); + + +/* Routines to manipulate the state stack. */ + +static inline void +push (struct unw_state_record *sr) +{ + struct unw_reg_state *rs; + + rs = alloc_reg_state(); + if (!rs) { + printk(KERN_ERR "unwind: cannot stack reg state!\n"); + return; + } + memcpy(rs, &sr->curr, sizeof(*rs)); + sr->curr.next = rs; +} + +static void +pop (struct unw_state_record *sr) +{ + struct unw_reg_state *rs = sr->curr.next; + + if (!rs) { + printk(KERN_ERR "unwind: stack underflow!\n"); + return; + } + memcpy(&sr->curr, rs, sizeof(*rs)); + free_reg_state(rs); +} + +/* Make a copy of the state stack. Non-recursive to avoid stack overflows. */ +static struct unw_reg_state * +dup_state_stack (struct unw_reg_state *rs) +{ + struct unw_reg_state *copy, *prev = NULL, *first = NULL; + + while (rs) { + copy = alloc_reg_state(); + if (!copy) { + printk(KERN_ERR "unwind.dup_state_stack: out of memory\n"); + return NULL; + } + memcpy(copy, rs, sizeof(*copy)); + if (first) + prev->next = copy; + else + first = copy; + rs = rs->next; + prev = copy; + } + return first; +} + +/* Free all stacked register states (but not RS itself). */ +static void +free_state_stack (struct unw_reg_state *rs) +{ + struct unw_reg_state *p, *next; + + for (p = rs->next; p != NULL; p = next) { + next = p->next; + free_reg_state(p); + } + rs->next = NULL; +} + +/* Unwind decoder routines */ + +static enum unw_register_index __attribute_const__ +decode_abreg (unsigned char abreg, int memory) +{ + switch (abreg) { + case 0x04 ... 0x07: return UNW_REG_R4 + (abreg - 0x04); + case 0x22 ... 0x25: return UNW_REG_F2 + (abreg - 0x22); + case 0x30 ... 0x3f: return UNW_REG_F16 + (abreg - 0x30); + case 0x41 ... 0x45: return UNW_REG_B1 + (abreg - 0x41); + case 0x60: return UNW_REG_PR; + case 0x61: return UNW_REG_PSP; + case 0x62: return memory ? UNW_REG_PRI_UNAT_MEM : UNW_REG_PRI_UNAT_GR; + case 0x63: return UNW_REG_RP; + case 0x64: return UNW_REG_BSP; + case 0x65: return UNW_REG_BSPSTORE; + case 0x66: return UNW_REG_RNAT; + case 0x67: return UNW_REG_UNAT; + case 0x68: return UNW_REG_FPSR; + case 0x69: return UNW_REG_PFS; + case 0x6a: return UNW_REG_LC; + default: + break; + } + UNW_DPRINT(0, "unwind.%s: bad abreg=0x%x\n", __func__, abreg); + return UNW_REG_LC; +} + +static void +set_reg (struct unw_reg_info *reg, enum unw_where where, int when, unsigned long val) +{ + reg->val = val; + reg->where = where; + if (reg->when == UNW_WHEN_NEVER) + reg->when = when; +} + +static void +alloc_spill_area (unsigned long *offp, unsigned long regsize, + struct unw_reg_info *lo, struct unw_reg_info *hi) +{ + struct unw_reg_info *reg; + + for (reg = hi; reg >= lo; --reg) { + if (reg->where == UNW_WHERE_SPILL_HOME) { + reg->where = UNW_WHERE_PSPREL; + *offp -= regsize; + reg->val = *offp; + } + } +} + +static inline void +spill_next_when (struct unw_reg_info **regp, struct unw_reg_info *lim, unw_word t) +{ + struct unw_reg_info *reg; + + for (reg = *regp; reg <= lim; ++reg) { + if (reg->where == UNW_WHERE_SPILL_HOME) { + reg->when = t; + *regp = reg + 1; + return; + } + } + UNW_DPRINT(0, "unwind.%s: excess spill!\n", __func__); +} + +static inline void +finish_prologue (struct unw_state_record *sr) +{ + struct unw_reg_info *reg; + unsigned long off; + int i; + + /* + * First, resolve implicit register save locations (see Section "11.4.2.3 Rules + * for Using Unwind Descriptors", rule 3): + */ + for (i = 0; i < (int) ARRAY_SIZE(unw.save_order); ++i) { + reg = sr->curr.reg + unw.save_order[i]; + if (reg->where == UNW_WHERE_GR_SAVE) { + reg->where = UNW_WHERE_GR; + reg->val = sr->gr_save_loc++; + } + } + + /* + * Next, compute when the fp, general, and branch registers get + * saved. This must come before alloc_spill_area() because + * we need to know which registers are spilled to their home + * locations. + */ + if (sr->imask) { + unsigned char kind, mask = 0, *cp = sr->imask; + int t; + static const unsigned char limit[3] = { + UNW_REG_F31, UNW_REG_R7, UNW_REG_B5 + }; + struct unw_reg_info *(regs[3]); + + regs[0] = sr->curr.reg + UNW_REG_F2; + regs[1] = sr->curr.reg + UNW_REG_R4; + regs[2] = sr->curr.reg + UNW_REG_B1; + + for (t = 0; t < sr->region_len; ++t) { + if ((t & 3) == 0) + mask = *cp++; + kind = (mask >> 2*(3-(t & 3))) & 3; + if (kind > 0) + spill_next_when(®s[kind - 1], sr->curr.reg + limit[kind - 1], + sr->region_start + t); + } + } + /* + * Next, lay out the memory stack spill area: + */ + if (sr->any_spills) { + off = sr->spill_offset; + alloc_spill_area(&off, 16, sr->curr.reg + UNW_REG_F2, sr->curr.reg + UNW_REG_F31); + alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_B1, sr->curr.reg + UNW_REG_B5); + alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_R4, sr->curr.reg + UNW_REG_R7); + } +} + +/* + * Region header descriptors. + */ + +static void +desc_prologue (int body, unw_word rlen, unsigned char mask, unsigned char grsave, + struct unw_state_record *sr) +{ + int i, region_start; + + if (!(sr->in_body || sr->first_region)) + finish_prologue(sr); + sr->first_region = 0; + + /* check if we're done: */ + if (sr->when_target < sr->region_start + sr->region_len) { + sr->done = 1; + return; + } + + region_start = sr->region_start + sr->region_len; + + for (i = 0; i < sr->epilogue_count; ++i) + pop(sr); + sr->epilogue_count = 0; + sr->epilogue_start = UNW_WHEN_NEVER; + + sr->region_start = region_start; + sr->region_len = rlen; + sr->in_body = body; + + if (!body) { + push(sr); + + for (i = 0; i < 4; ++i) { + if (mask & 0x8) + set_reg(sr->curr.reg + unw.save_order[i], UNW_WHERE_GR, + sr->region_start + sr->region_len - 1, grsave++); + mask <<= 1; + } + sr->gr_save_loc = grsave; + sr->any_spills = 0; + sr->imask = NULL; + sr->spill_offset = 0x10; /* default to psp+16 */ + } +} + +/* + * Prologue descriptors. + */ + +static inline void +desc_abi (unsigned char abi, unsigned char context, struct unw_state_record *sr) +{ + if (abi == 3 && context == 'i') { + sr->flags |= UNW_FLAG_INTERRUPT_FRAME; + UNW_DPRINT(3, "unwind.%s: interrupt frame\n", __func__); + } + else + UNW_DPRINT(0, "unwind%s: ignoring unwabi(abi=0x%x,context=0x%x)\n", + __func__, abi, context); +} + +static inline void +desc_br_gr (unsigned char brmask, unsigned char gr, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 5; ++i) { + if (brmask & 1) + set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_GR, + sr->region_start + sr->region_len - 1, gr++); + brmask >>= 1; + } +} + +static inline void +desc_br_mem (unsigned char brmask, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 5; ++i) { + if (brmask & 1) { + set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_SPILL_HOME, + sr->region_start + sr->region_len - 1, 0); + sr->any_spills = 1; + } + brmask >>= 1; + } +} + +static inline void +desc_frgr_mem (unsigned char grmask, unw_word frmask, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 4; ++i) { + if ((grmask & 1) != 0) { + set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME, + sr->region_start + sr->region_len - 1, 0); + sr->any_spills = 1; + } + grmask >>= 1; + } + for (i = 0; i < 20; ++i) { + if ((frmask & 1) != 0) { + int base = (i < 4) ? UNW_REG_F2 : UNW_REG_F16 - 4; + set_reg(sr->curr.reg + base + i, UNW_WHERE_SPILL_HOME, + sr->region_start + sr->region_len - 1, 0); + sr->any_spills = 1; + } + frmask >>= 1; + } +} + +static inline void +desc_fr_mem (unsigned char frmask, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 4; ++i) { + if ((frmask & 1) != 0) { + set_reg(sr->curr.reg + UNW_REG_F2 + i, UNW_WHERE_SPILL_HOME, + sr->region_start + sr->region_len - 1, 0); + sr->any_spills = 1; + } + frmask >>= 1; + } +} + +static inline void +desc_gr_gr (unsigned char grmask, unsigned char gr, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 4; ++i) { + if ((grmask & 1) != 0) + set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_GR, + sr->region_start + sr->region_len - 1, gr++); + grmask >>= 1; + } +} + +static inline void +desc_gr_mem (unsigned char grmask, struct unw_state_record *sr) +{ + int i; + + for (i = 0; i < 4; ++i) { + if ((grmask & 1) != 0) { + set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME, + sr->region_start + sr->region_len - 1, 0); + sr->any_spills = 1; + } + grmask >>= 1; + } +} + +static inline void +desc_mem_stack_f (unw_word t, unw_word size, struct unw_state_record *sr) +{ + set_reg(sr->curr.reg + UNW_REG_PSP, UNW_WHERE_NONE, + sr->region_start + min_t(int, t, sr->region_len - 1), 16*size); +} + +static inline void +desc_mem_stack_v (unw_word t, struct unw_state_record *sr) +{ + sr->curr.reg[UNW_REG_PSP].when = sr->region_start + min_t(int, t, sr->region_len - 1); +} + +static inline void +desc_reg_gr (unsigned char reg, unsigned char dst, struct unw_state_record *sr) +{ + set_reg(sr->curr.reg + reg, UNW_WHERE_GR, sr->region_start + sr->region_len - 1, dst); +} + +static inline void +desc_reg_psprel (unsigned char reg, unw_word pspoff, struct unw_state_record *sr) +{ + set_reg(sr->curr.reg + reg, UNW_WHERE_PSPREL, sr->region_start + sr->region_len - 1, + 0x10 - 4*pspoff); +} + +static inline void +desc_reg_sprel (unsigned char reg, unw_word spoff, struct unw_state_record *sr) +{ + set_reg(sr->curr.reg + reg, UNW_WHERE_SPREL, sr->region_start + sr->region_len - 1, + 4*spoff); +} + +static inline void +desc_rp_br (unsigned char dst, struct unw_state_record *sr) +{ + sr->return_link_reg = dst; +} + +static inline void +desc_reg_when (unsigned char regnum, unw_word t, struct unw_state_record *sr) +{ + struct unw_reg_info *reg = sr->curr.reg + regnum; + + if (reg->where == UNW_WHERE_NONE) + reg->where = UNW_WHERE_GR_SAVE; + reg->when = sr->region_start + min_t(int, t, sr->region_len - 1); +} + +static inline void +desc_spill_base (unw_word pspoff, struct unw_state_record *sr) +{ + sr->spill_offset = 0x10 - 4*pspoff; +} + +static inline unsigned char * +desc_spill_mask (unsigned char *imaskp, struct unw_state_record *sr) +{ + sr->imask = imaskp; + return imaskp + (2*sr->region_len + 7)/8; +} + +/* + * Body descriptors. + */ +static inline void +desc_epilogue (unw_word t, unw_word ecount, struct unw_state_record *sr) +{ + sr->epilogue_start = sr->region_start + sr->region_len - 1 - t; + sr->epilogue_count = ecount + 1; +} + +static inline void +desc_copy_state (unw_word label, struct unw_state_record *sr) +{ + struct unw_labeled_state *ls; + + for (ls = sr->labeled_states; ls; ls = ls->next) { + if (ls->label == label) { + free_state_stack(&sr->curr); + memcpy(&sr->curr, &ls->saved_state, sizeof(sr->curr)); + sr->curr.next = dup_state_stack(ls->saved_state.next); + return; + } + } + printk(KERN_ERR "unwind: failed to find state labeled 0x%lx\n", label); +} + +static inline void +desc_label_state (unw_word label, struct unw_state_record *sr) +{ + struct unw_labeled_state *ls; + + ls = alloc_labeled_state(); + if (!ls) { + printk(KERN_ERR "unwind.desc_label_state(): out of memory\n"); + return; + } + ls->label = label; + memcpy(&ls->saved_state, &sr->curr, sizeof(ls->saved_state)); + ls->saved_state.next = dup_state_stack(sr->curr.next); + + /* insert into list of labeled states: */ + ls->next = sr->labeled_states; + sr->labeled_states = ls; +} + +/* + * General descriptors. + */ + +static inline int +desc_is_active (unsigned char qp, unw_word t, struct unw_state_record *sr) +{ + if (sr->when_target <= sr->region_start + min_t(int, t, sr->region_len - 1)) + return 0; + if (qp > 0) { + if ((sr->pr_val & (1UL << qp)) == 0) + return 0; + sr->pr_mask |= (1UL << qp); + } + return 1; +} + +static inline void +desc_restore_p (unsigned char qp, unw_word t, unsigned char abreg, struct unw_state_record *sr) +{ + struct unw_reg_info *r; + + if (!desc_is_active(qp, t, sr)) + return; + + r = sr->curr.reg + decode_abreg(abreg, 0); + r->where = UNW_WHERE_NONE; + r->when = UNW_WHEN_NEVER; + r->val = 0; +} + +static inline void +desc_spill_reg_p (unsigned char qp, unw_word t, unsigned char abreg, unsigned char x, + unsigned char ytreg, struct unw_state_record *sr) +{ + enum unw_where where = UNW_WHERE_GR; + struct unw_reg_info *r; + + if (!desc_is_active(qp, t, sr)) + return; + + if (x) + where = UNW_WHERE_BR; + else if (ytreg & 0x80) + where = UNW_WHERE_FR; + + r = sr->curr.reg + decode_abreg(abreg, 0); + r->where = where; + r->when = sr->region_start + min_t(int, t, sr->region_len - 1); + r->val = (ytreg & 0x7f); +} + +static inline void +desc_spill_psprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word pspoff, + struct unw_state_record *sr) +{ + struct unw_reg_info *r; + + if (!desc_is_active(qp, t, sr)) + return; + + r = sr->curr.reg + decode_abreg(abreg, 1); + r->where = UNW_WHERE_PSPREL; + r->when = sr->region_start + min_t(int, t, sr->region_len - 1); + r->val = 0x10 - 4*pspoff; +} + +static inline void +desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word spoff, + struct unw_state_record *sr) +{ + struct unw_reg_info *r; + + if (!desc_is_active(qp, t, sr)) + return; + + r = sr->curr.reg + decode_abreg(abreg, 1); + r->where = UNW_WHERE_SPREL; + r->when = sr->region_start + min_t(int, t, sr->region_len - 1); + r->val = 4*spoff; +} + +#define UNW_DEC_BAD_CODE(code) printk(KERN_ERR "unwind: unknown code 0x%02x\n", \ + code); + +/* + * region headers: + */ +#define UNW_DEC_PROLOGUE_GR(fmt,r,m,gr,arg) desc_prologue(0,r,m,gr,arg) +#define UNW_DEC_PROLOGUE(fmt,b,r,arg) desc_prologue(b,r,0,32,arg) +/* + * prologue descriptors: + */ +#define UNW_DEC_ABI(fmt,a,c,arg) desc_abi(a,c,arg) +#define UNW_DEC_BR_GR(fmt,b,g,arg) desc_br_gr(b,g,arg) +#define UNW_DEC_BR_MEM(fmt,b,arg) desc_br_mem(b,arg) +#define UNW_DEC_FRGR_MEM(fmt,g,f,arg) desc_frgr_mem(g,f,arg) +#define UNW_DEC_FR_MEM(fmt,f,arg) desc_fr_mem(f,arg) +#define UNW_DEC_GR_GR(fmt,m,g,arg) desc_gr_gr(m,g,arg) +#define UNW_DEC_GR_MEM(fmt,m,arg) desc_gr_mem(m,arg) +#define UNW_DEC_MEM_STACK_F(fmt,t,s,arg) desc_mem_stack_f(t,s,arg) +#define UNW_DEC_MEM_STACK_V(fmt,t,arg) desc_mem_stack_v(t,arg) +#define UNW_DEC_REG_GR(fmt,r,d,arg) desc_reg_gr(r,d,arg) +#define UNW_DEC_REG_PSPREL(fmt,r,o,arg) desc_reg_psprel(r,o,arg) +#define UNW_DEC_REG_SPREL(fmt,r,o,arg) desc_reg_sprel(r,o,arg) +#define UNW_DEC_REG_WHEN(fmt,r,t,arg) desc_reg_when(r,t,arg) +#define UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_GR,t,arg) +#define UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_MEM,t,arg) +#define UNW_DEC_PRIUNAT_GR(fmt,r,arg) desc_reg_gr(UNW_REG_PRI_UNAT_GR,r,arg) +#define UNW_DEC_PRIUNAT_PSPREL(fmt,o,arg) desc_reg_psprel(UNW_REG_PRI_UNAT_MEM,o,arg) +#define UNW_DEC_PRIUNAT_SPREL(fmt,o,arg) desc_reg_sprel(UNW_REG_PRI_UNAT_MEM,o,arg) +#define UNW_DEC_RP_BR(fmt,d,arg) desc_rp_br(d,arg) +#define UNW_DEC_SPILL_BASE(fmt,o,arg) desc_spill_base(o,arg) +#define UNW_DEC_SPILL_MASK(fmt,m,arg) (m = desc_spill_mask(m,arg)) +/* + * body descriptors: + */ +#define UNW_DEC_EPILOGUE(fmt,t,c,arg) desc_epilogue(t,c,arg) +#define UNW_DEC_COPY_STATE(fmt,l,arg) desc_copy_state(l,arg) +#define UNW_DEC_LABEL_STATE(fmt,l,arg) desc_label_state(l,arg) +/* + * general unwind descriptors: + */ +#define UNW_DEC_SPILL_REG_P(f,p,t,a,x,y,arg) desc_spill_reg_p(p,t,a,x,y,arg) +#define UNW_DEC_SPILL_REG(f,t,a,x,y,arg) desc_spill_reg_p(0,t,a,x,y,arg) +#define UNW_DEC_SPILL_PSPREL_P(f,p,t,a,o,arg) desc_spill_psprel_p(p,t,a,o,arg) +#define UNW_DEC_SPILL_PSPREL(f,t,a,o,arg) desc_spill_psprel_p(0,t,a,o,arg) +#define UNW_DEC_SPILL_SPREL_P(f,p,t,a,o,arg) desc_spill_sprel_p(p,t,a,o,arg) +#define UNW_DEC_SPILL_SPREL(f,t,a,o,arg) desc_spill_sprel_p(0,t,a,o,arg) +#define UNW_DEC_RESTORE_P(f,p,t,a,arg) desc_restore_p(p,t,a,arg) +#define UNW_DEC_RESTORE(f,t,a,arg) desc_restore_p(0,t,a,arg) + +#include "unwind_decoder.c" + + +/* Unwind scripts. */ + +static inline unw_hash_index_t +hash (unsigned long ip) +{ + /* magic number = ((sqrt(5)-1)/2)*2^64 */ + static const unsigned long hashmagic = 0x9e3779b97f4a7c16UL; + + return (ip >> 4) * hashmagic >> (64 - UNW_LOG_HASH_SIZE); +} + +static inline long +cache_match (struct unw_script *script, unsigned long ip, unsigned long pr) +{ + read_lock(&script->lock); + if (ip == script->ip && ((pr ^ script->pr_val) & script->pr_mask) == 0) + /* keep the read lock... */ + return 1; + read_unlock(&script->lock); + return 0; +} + +static inline struct unw_script * +script_lookup (struct unw_frame_info *info) +{ + struct unw_script *script = unw.cache + info->hint; + unsigned short index; + unsigned long ip, pr; + + if (UNW_DEBUG_ON(0)) + return NULL; /* Always regenerate scripts in debug mode */ + + STAT(++unw.stat.cache.lookups); + + ip = info->ip; + pr = info->pr; + + if (cache_match(script, ip, pr)) { + STAT(++unw.stat.cache.hinted_hits); + return script; + } + + index = unw.hash[hash(ip)]; + if (index >= UNW_CACHE_SIZE) + return NULL; + + script = unw.cache + index; + while (1) { + if (cache_match(script, ip, pr)) { + /* update hint; no locking required as single-word writes are atomic */ + STAT(++unw.stat.cache.normal_hits); + unw.cache[info->prev_script].hint = script - unw.cache; + return script; + } + if (script->coll_chain >= UNW_HASH_SIZE) + return NULL; + script = unw.cache + script->coll_chain; + STAT(++unw.stat.cache.collision_chain_traversals); + } +} + +/* + * On returning, a write lock for the SCRIPT is still being held. + */ +static inline struct unw_script * +script_new (unsigned long ip) +{ + struct unw_script *script, *prev, *tmp; + unw_hash_index_t index; + unsigned short head; + + STAT(++unw.stat.script.news); + + /* + * Can't (easily) use cmpxchg() here because of ABA problem + * that is intrinsic in cmpxchg()... + */ + head = unw.lru_head; + script = unw.cache + head; + unw.lru_head = script->lru_chain; + + /* + * We'd deadlock here if we interrupted a thread that is holding a read lock on + * script->lock. Thus, if the write_trylock() fails, we simply bail out. The + * alternative would be to disable interrupts whenever we hold a read-lock, but + * that seems silly. + */ + if (!write_trylock(&script->lock)) + return NULL; + + /* re-insert script at the tail of the LRU chain: */ + unw.cache[unw.lru_tail].lru_chain = head; + unw.lru_tail = head; + + /* remove the old script from the hash table (if it's there): */ + if (script->ip) { + index = hash(script->ip); + tmp = unw.cache + unw.hash[index]; + prev = NULL; + while (1) { + if (tmp == script) { + if (prev) + prev->coll_chain = tmp->coll_chain; + else + unw.hash[index] = tmp->coll_chain; + break; + } else + prev = tmp; + if (tmp->coll_chain >= UNW_CACHE_SIZE) + /* old script wasn't in the hash-table */ + break; + tmp = unw.cache + tmp->coll_chain; + } + } + + /* enter new script in the hash table */ + index = hash(ip); + script->coll_chain = unw.hash[index]; + unw.hash[index] = script - unw.cache; + + script->ip = ip; /* set new IP while we're holding the locks */ + + STAT(if (script->coll_chain < UNW_CACHE_SIZE) ++unw.stat.script.collisions); + + script->flags = 0; + script->hint = 0; + script->count = 0; + return script; +} + +static void +script_finalize (struct unw_script *script, struct unw_state_record *sr) +{ + script->pr_mask = sr->pr_mask; + script->pr_val = sr->pr_val; + /* + * We could down-grade our write-lock on script->lock here but + * the rwlock API doesn't offer atomic lock downgrading, so + * we'll just keep the write-lock and release it later when + * we're done using the script. + */ +} + +static inline void +script_emit (struct unw_script *script, struct unw_insn insn) +{ + if (script->count >= UNW_MAX_SCRIPT_LEN) { + UNW_DPRINT(0, "unwind.%s: script exceeds maximum size of %u instructions!\n", + __func__, UNW_MAX_SCRIPT_LEN); + return; + } + script->insn[script->count++] = insn; +} + +static inline void +emit_nat_info (struct unw_state_record *sr, int i, struct unw_script *script) +{ + struct unw_reg_info *r = sr->curr.reg + i; + enum unw_insn_opcode opc; + struct unw_insn insn; + unsigned long val = 0; + + switch (r->where) { + case UNW_WHERE_GR: + if (r->val >= 32) { + /* register got spilled to a stacked register */ + opc = UNW_INSN_SETNAT_TYPE; + val = UNW_NAT_REGSTK; + } else + /* register got spilled to a scratch register */ + opc = UNW_INSN_SETNAT_MEMSTK; + break; + + case UNW_WHERE_FR: + opc = UNW_INSN_SETNAT_TYPE; + val = UNW_NAT_VAL; + break; + + case UNW_WHERE_BR: + opc = UNW_INSN_SETNAT_TYPE; + val = UNW_NAT_NONE; + break; + + case UNW_WHERE_PSPREL: + case UNW_WHERE_SPREL: + opc = UNW_INSN_SETNAT_MEMSTK; + break; + + default: + UNW_DPRINT(0, "unwind.%s: don't know how to emit nat info for where = %u\n", + __func__, r->where); + return; + } + insn.opc = opc; + insn.dst = unw.preg_index[i]; + insn.val = val; + script_emit(script, insn); +} + +static void +compile_reg (struct unw_state_record *sr, int i, struct unw_script *script) +{ + struct unw_reg_info *r = sr->curr.reg + i; + enum unw_insn_opcode opc; + unsigned long val, rval; + struct unw_insn insn; + long need_nat_info; + + if (r->where == UNW_WHERE_NONE || r->when >= sr->when_target) + return; + + opc = UNW_INSN_MOVE; + val = rval = r->val; + need_nat_info = (i >= UNW_REG_R4 && i <= UNW_REG_R7); + + switch (r->where) { + case UNW_WHERE_GR: + if (rval >= 32) { + opc = UNW_INSN_MOVE_STACKED; + val = rval - 32; + } else if (rval >= 4 && rval <= 7) { + if (need_nat_info) { + opc = UNW_INSN_MOVE2; + need_nat_info = 0; + } + val = unw.preg_index[UNW_REG_R4 + (rval - 4)]; + } else if (rval == 0) { + opc = UNW_INSN_MOVE_CONST; + val = 0; + } else { + /* register got spilled to a scratch register */ + opc = UNW_INSN_MOVE_SCRATCH; + val = pt_regs_off(rval); + } + break; + + case UNW_WHERE_FR: + if (rval <= 5) + val = unw.preg_index[UNW_REG_F2 + (rval - 2)]; + else if (rval >= 16 && rval <= 31) + val = unw.preg_index[UNW_REG_F16 + (rval - 16)]; + else { + opc = UNW_INSN_MOVE_SCRATCH; + if (rval <= 11) + val = offsetof(struct pt_regs, f6) + 16*(rval - 6); + else + UNW_DPRINT(0, "unwind.%s: kernel may not touch f%lu\n", + __func__, rval); + } + break; + + case UNW_WHERE_BR: + if (rval >= 1 && rval <= 5) + val = unw.preg_index[UNW_REG_B1 + (rval - 1)]; + else { + opc = UNW_INSN_MOVE_SCRATCH; + if (rval == 0) + val = offsetof(struct pt_regs, b0); + else if (rval == 6) + val = offsetof(struct pt_regs, b6); + else + val = offsetof(struct pt_regs, b7); + } + break; + + case UNW_WHERE_SPREL: + opc = UNW_INSN_ADD_SP; + break; + + case UNW_WHERE_PSPREL: + opc = UNW_INSN_ADD_PSP; + break; + + default: + UNW_DPRINT(0, "unwind%s: register %u has unexpected `where' value of %u\n", + __func__, i, r->where); + break; + } + insn.opc = opc; + insn.dst = unw.preg_index[i]; + insn.val = val; + script_emit(script, insn); + if (need_nat_info) + emit_nat_info(sr, i, script); + + if (i == UNW_REG_PSP) { + /* + * info->psp must contain the _value_ of the previous + * sp, not it's save location. We get this by + * dereferencing the value we just stored in + * info->psp: + */ + insn.opc = UNW_INSN_LOAD; + insn.dst = insn.val = unw.preg_index[UNW_REG_PSP]; + script_emit(script, insn); + } +} + +static inline const struct unw_table_entry * +lookup (struct unw_table *table, unsigned long rel_ip) +{ + const struct unw_table_entry *e = NULL; + unsigned long lo, hi, mid; + + /* do a binary search for right entry: */ + for (lo = 0, hi = table->length; lo < hi; ) { + mid = (lo + hi) / 2; + e = &table->array[mid]; + if (rel_ip < e->start_offset) + hi = mid; + else if (rel_ip >= e->end_offset) + lo = mid + 1; + else + break; + } + if (rel_ip < e->start_offset || rel_ip >= e->end_offset) + return NULL; + return e; +} + +/* + * Build an unwind script that unwinds from state OLD_STATE to the + * entrypoint of the function that called OLD_STATE. + */ +static inline struct unw_script * +build_script (struct unw_frame_info *info) +{ + const struct unw_table_entry *e = NULL; + struct unw_script *script = NULL; + struct unw_labeled_state *ls, *next; + unsigned long ip = info->ip; + struct unw_state_record sr; + struct unw_table *table, *prev; + struct unw_reg_info *r; + struct unw_insn insn; + u8 *dp, *desc_end; + u64 hdr; + int i; + STAT(unsigned long start, parse_start;) + + STAT(++unw.stat.script.builds; start = ia64_get_itc()); + + /* build state record */ + memset(&sr, 0, sizeof(sr)); + for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) + r->when = UNW_WHEN_NEVER; + sr.pr_val = info->pr; + + UNW_DPRINT(3, "unwind.%s: ip 0x%lx\n", __func__, ip); + script = script_new(ip); + if (!script) { + UNW_DPRINT(0, "unwind.%s: failed to create unwind script\n", __func__); + STAT(unw.stat.script.build_time += ia64_get_itc() - start); + return NULL; + } + unw.cache[info->prev_script].hint = script - unw.cache; + + /* search the kernels and the modules' unwind tables for IP: */ + + STAT(parse_start = ia64_get_itc()); + + prev = NULL; + for (table = unw.tables; table; table = table->next) { + if (ip >= table->start && ip < table->end) { + /* + * Leave the kernel unwind table at the very front, + * lest moving it breaks some assumption elsewhere. + * Otherwise, move the matching table to the second + * position in the list so that traversals can benefit + * from commonality in backtrace paths. + */ + if (prev && prev != unw.tables) { + /* unw is safe - we're already spinlocked */ + prev->next = table->next; + table->next = unw.tables->next; + unw.tables->next = table; + } + e = lookup(table, ip - table->segment_base); + break; + } + prev = table; + } + if (!e) { + /* no info, return default unwinder (leaf proc, no mem stack, no saved regs) */ + UNW_DPRINT(1, "unwind.%s: no unwind info for ip=0x%lx (prev ip=0x%lx)\n", + __func__, ip, unw.cache[info->prev_script].ip); + sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR; + sr.curr.reg[UNW_REG_RP].when = -1; + sr.curr.reg[UNW_REG_RP].val = 0; + compile_reg(&sr, UNW_REG_RP, script); + script_finalize(script, &sr); + STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start); + STAT(unw.stat.script.build_time += ia64_get_itc() - start); + return script; + } + + sr.when_target = (3*((ip & ~0xfUL) - (table->segment_base + e->start_offset))/16 + + (ip & 0xfUL)); + hdr = *(u64 *) (table->segment_base + e->info_offset); + dp = (u8 *) (table->segment_base + e->info_offset + 8); + desc_end = dp + 8*UNW_LENGTH(hdr); + + while (!sr.done && dp < desc_end) + dp = unw_decode(dp, sr.in_body, &sr); + + if (sr.when_target > sr.epilogue_start) { + /* + * sp has been restored and all values on the memory stack below + * psp also have been restored. + */ + sr.curr.reg[UNW_REG_PSP].val = 0; + sr.curr.reg[UNW_REG_PSP].where = UNW_WHERE_NONE; + sr.curr.reg[UNW_REG_PSP].when = UNW_WHEN_NEVER; + for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) + if ((r->where == UNW_WHERE_PSPREL && r->val <= 0x10) + || r->where == UNW_WHERE_SPREL) + { + r->val = 0; + r->where = UNW_WHERE_NONE; + r->when = UNW_WHEN_NEVER; + } + } + + script->flags = sr.flags; + + /* + * If RP did't get saved, generate entry for the return link + * register. + */ + if (sr.curr.reg[UNW_REG_RP].when >= sr.when_target) { + sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR; + sr.curr.reg[UNW_REG_RP].when = -1; + sr.curr.reg[UNW_REG_RP].val = sr.return_link_reg; + UNW_DPRINT(1, "unwind.%s: using default for rp at ip=0x%lx where=%d val=0x%lx\n", + __func__, ip, sr.curr.reg[UNW_REG_RP].where, + sr.curr.reg[UNW_REG_RP].val); + } + +#ifdef UNW_DEBUG + UNW_DPRINT(1, "unwind.%s: state record for func 0x%lx, t=%u:\n", + __func__, table->segment_base + e->start_offset, sr.when_target); + for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) { + if (r->where != UNW_WHERE_NONE || r->when != UNW_WHEN_NEVER) { + UNW_DPRINT(1, " %s <- ", unw.preg_name[r - sr.curr.reg]); + switch (r->where) { + case UNW_WHERE_GR: UNW_DPRINT(1, "r%lu", r->val); break; + case UNW_WHERE_FR: UNW_DPRINT(1, "f%lu", r->val); break; + case UNW_WHERE_BR: UNW_DPRINT(1, "b%lu", r->val); break; + case UNW_WHERE_SPREL: UNW_DPRINT(1, "[sp+0x%lx]", r->val); break; + case UNW_WHERE_PSPREL: UNW_DPRINT(1, "[psp+0x%lx]", r->val); break; + case UNW_WHERE_NONE: + UNW_DPRINT(1, "%s+0x%lx", unw.preg_name[r - sr.curr.reg], r->val); + break; + + default: + UNW_DPRINT(1, "BADWHERE(%d)", r->where); + break; + } + UNW_DPRINT(1, "\t\t%d\n", r->when); + } + } +#endif + + STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start); + + /* translate state record into unwinder instructions: */ + + /* + * First, set psp if we're dealing with a fixed-size frame; + * subsequent instructions may depend on this value. + */ + if (sr.when_target > sr.curr.reg[UNW_REG_PSP].when + && (sr.curr.reg[UNW_REG_PSP].where == UNW_WHERE_NONE) + && sr.curr.reg[UNW_REG_PSP].val != 0) { + /* new psp is sp plus frame size */ + insn.opc = UNW_INSN_ADD; + insn.dst = offsetof(struct unw_frame_info, psp)/8; + insn.val = sr.curr.reg[UNW_REG_PSP].val; /* frame size */ + script_emit(script, insn); + } + + /* determine where the primary UNaT is: */ + if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_GR].when) + i = UNW_REG_PRI_UNAT_MEM; + else if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when) + i = UNW_REG_PRI_UNAT_GR; + else if (sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when > sr.curr.reg[UNW_REG_PRI_UNAT_GR].when) + i = UNW_REG_PRI_UNAT_MEM; + else + i = UNW_REG_PRI_UNAT_GR; + + compile_reg(&sr, i, script); + + for (i = UNW_REG_BSP; i < UNW_NUM_REGS; ++i) + compile_reg(&sr, i, script); + + /* free labeled register states & stack: */ + + STAT(parse_start = ia64_get_itc()); + for (ls = sr.labeled_states; ls; ls = next) { + next = ls->next; + free_state_stack(&ls->saved_state); + free_labeled_state(ls); + } + free_state_stack(&sr.curr); + STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start); + + script_finalize(script, &sr); + STAT(unw.stat.script.build_time += ia64_get_itc() - start); + return script; +} + +/* + * Apply the unwinding actions represented by OPS and update SR to + * reflect the state that existed upon entry to the function that this + * unwinder represents. + */ +static inline void +run_script (struct unw_script *script, struct unw_frame_info *state) +{ + struct unw_insn *ip, *limit, next_insn; + unsigned long opc, dst, val, off; + unsigned long *s = (unsigned long *) state; + STAT(unsigned long start;) + + STAT(++unw.stat.script.runs; start = ia64_get_itc()); + state->flags = script->flags; + ip = script->insn; + limit = script->insn + script->count; + next_insn = *ip; + + while (ip++ < limit) { + opc = next_insn.opc; + dst = next_insn.dst; + val = next_insn.val; + next_insn = *ip; + + redo: + switch (opc) { + case UNW_INSN_ADD: + s[dst] += val; + break; + + case UNW_INSN_MOVE2: + if (!s[val]) + goto lazy_init; + s[dst+1] = s[val+1]; + s[dst] = s[val]; + break; + + case UNW_INSN_MOVE: + if (!s[val]) + goto lazy_init; + s[dst] = s[val]; + break; + + case UNW_INSN_MOVE_SCRATCH: + if (state->pt) { + s[dst] = (unsigned long) get_scratch_regs(state) + val; + } else { + s[dst] = 0; + UNW_DPRINT(0, "unwind.%s: no state->pt, dst=%ld, val=%ld\n", + __func__, dst, val); + } + break; + + case UNW_INSN_MOVE_CONST: + if (val == 0) + s[dst] = (unsigned long) &unw.r0; + else { + s[dst] = 0; + UNW_DPRINT(0, "unwind.%s: UNW_INSN_MOVE_CONST bad val=%ld\n", + __func__, val); + } + break; + + + case UNW_INSN_MOVE_STACKED: + s[dst] = (unsigned long) ia64_rse_skip_regs((unsigned long *)state->bsp, + val); + break; + + case UNW_INSN_ADD_PSP: + s[dst] = state->psp + val; + break; + + case UNW_INSN_ADD_SP: + s[dst] = state->sp + val; + break; + + case UNW_INSN_SETNAT_MEMSTK: + if (!state->pri_unat_loc) + state->pri_unat_loc = &state->sw->caller_unat; + /* register off. is a multiple of 8, so the least 3 bits (type) are 0 */ + s[dst+1] = ((unsigned long) state->pri_unat_loc - s[dst]) | UNW_NAT_MEMSTK; + break; + + case UNW_INSN_SETNAT_TYPE: + s[dst+1] = val; + break; + + case UNW_INSN_LOAD: +#ifdef UNW_DEBUG + if ((s[val] & (local_cpu_data->unimpl_va_mask | 0x7)) != 0 + || s[val] < TASK_SIZE) + { + UNW_DPRINT(0, "unwind.%s: rejecting bad psp=0x%lx\n", + __func__, s[val]); + break; + } +#endif + s[dst] = *(unsigned long *) s[val]; + break; + } + } + STAT(unw.stat.script.run_time += ia64_get_itc() - start); + return; + + lazy_init: + off = unw.sw_off[val]; + s[val] = (unsigned long) state->sw + off; + if (off >= offsetof(struct switch_stack, r4) && off <= offsetof(struct switch_stack, r7)) + /* + * We're initializing a general register: init NaT info, too. Note that + * the offset is a multiple of 8 which gives us the 3 bits needed for + * the type field. + */ + s[val+1] = (offsetof(struct switch_stack, ar_unat) - off) | UNW_NAT_MEMSTK; + goto redo; +} + +static int +find_save_locs (struct unw_frame_info *info) +{ + int have_write_lock = 0; + struct unw_script *scr; + unsigned long flags = 0; + + if ((info->ip & (local_cpu_data->unimpl_va_mask | 0xf)) || info->ip < TASK_SIZE) { + /* don't let obviously bad addresses pollute the cache */ + /* FIXME: should really be level 0 but it occurs too often. KAO */ + UNW_DPRINT(1, "unwind.%s: rejecting bad ip=0x%lx\n", __func__, info->ip); + info->rp_loc = NULL; + return -1; + } + + scr = script_lookup(info); + if (!scr) { + spin_lock_irqsave(&unw.lock, flags); + scr = build_script(info); + if (!scr) { + spin_unlock_irqrestore(&unw.lock, flags); + UNW_DPRINT(0, + "unwind.%s: failed to locate/build unwind script for ip %lx\n", + __func__, info->ip); + return -1; + } + have_write_lock = 1; + } + info->hint = scr->hint; + info->prev_script = scr - unw.cache; + + run_script(scr, info); + + if (have_write_lock) { + write_unlock(&scr->lock); + spin_unlock_irqrestore(&unw.lock, flags); + } else + read_unlock(&scr->lock); + return 0; +} + +static int +unw_valid(const struct unw_frame_info *info, unsigned long* p) +{ + unsigned long loc = (unsigned long)p; + return (loc >= info->regstk.limit && loc < info->regstk.top) || + (loc >= info->memstk.top && loc < info->memstk.limit); +} + +int +unw_unwind (struct unw_frame_info *info) +{ + unsigned long prev_ip, prev_sp, prev_bsp; + unsigned long ip, pr, num_regs; + STAT(unsigned long start, flags;) + int retval; + + STAT(local_irq_save(flags); ++unw.stat.api.unwinds; start = ia64_get_itc()); + + prev_ip = info->ip; + prev_sp = info->sp; + prev_bsp = info->bsp; + + /* validate the return IP pointer */ + if (!unw_valid(info, info->rp_loc)) { + /* FIXME: should really be level 0 but it occurs too often. KAO */ + UNW_DPRINT(1, "unwind.%s: failed to locate return link (ip=0x%lx)!\n", + __func__, info->ip); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + /* restore the ip */ + ip = info->ip = *info->rp_loc; + if (ip < GATE_ADDR) { + UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", __func__, ip); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + + /* validate the previous stack frame pointer */ + if (!unw_valid(info, info->pfs_loc)) { + UNW_DPRINT(0, "unwind.%s: failed to locate ar.pfs!\n", __func__); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + /* restore the cfm: */ + info->cfm_loc = info->pfs_loc; + + /* restore the bsp: */ + pr = info->pr; + num_regs = 0; + if ((info->flags & UNW_FLAG_INTERRUPT_FRAME)) { + info->pt = info->sp + 16; + if ((pr & (1UL << PRED_NON_SYSCALL)) != 0) + num_regs = *info->cfm_loc & 0x7f; /* size of frame */ + info->pfs_loc = + (unsigned long *) (info->pt + offsetof(struct pt_regs, ar_pfs)); + UNW_DPRINT(3, "unwind.%s: interrupt_frame pt 0x%lx\n", __func__, info->pt); + } else + num_regs = (*info->cfm_loc >> 7) & 0x7f; /* size of locals */ + info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->bsp, -num_regs); + if (info->bsp < info->regstk.limit || info->bsp > info->regstk.top) { + UNW_DPRINT(0, "unwind.%s: bsp (0x%lx) out of range [0x%lx-0x%lx]\n", + __func__, info->bsp, info->regstk.limit, info->regstk.top); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + + /* restore the sp: */ + info->sp = info->psp; + if (info->sp < info->memstk.top || info->sp > info->memstk.limit) { + UNW_DPRINT(0, "unwind.%s: sp (0x%lx) out of range [0x%lx-0x%lx]\n", + __func__, info->sp, info->memstk.top, info->memstk.limit); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + + if (info->ip == prev_ip && info->sp == prev_sp && info->bsp == prev_bsp) { + UNW_DPRINT(0, "unwind.%s: ip, sp, bsp unchanged; stopping here (ip=0x%lx)\n", + __func__, ip); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return -1; + } + + /* as we unwind, the saved ar.unat becomes the primary unat: */ + info->pri_unat_loc = info->unat_loc; + + /* finally, restore the predicates: */ + unw_get_pr(info, &info->pr); + + retval = find_save_locs(info); + STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags)); + return retval; +} +EXPORT_SYMBOL(unw_unwind); + +int +unw_unwind_to_user (struct unw_frame_info *info) +{ + unsigned long ip, sp, pr = info->pr; + + do { + unw_get_sp(info, &sp); + if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp) + < IA64_PT_REGS_SIZE) { + UNW_DPRINT(0, "unwind.%s: ran off the top of the kernel stack\n", + __func__); + break; + } + if (unw_is_intr_frame(info) && + (pr & (1UL << PRED_USER_STACK))) + return 0; + if (unw_get_pr (info, &pr) < 0) { + unw_get_rp(info, &ip); + UNW_DPRINT(0, "unwind.%s: failed to read " + "predicate register (ip=0x%lx)\n", + __func__, ip); + return -1; + } + } while (unw_unwind(info) >= 0); + unw_get_ip(info, &ip); + UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n", + __func__, ip); + return -1; +} +EXPORT_SYMBOL(unw_unwind_to_user); + +static void +init_frame_info (struct unw_frame_info *info, struct task_struct *t, + struct switch_stack *sw, unsigned long stktop) +{ + unsigned long rbslimit, rbstop, stklimit; + STAT(unsigned long start, flags;) + + STAT(local_irq_save(flags); ++unw.stat.api.inits; start = ia64_get_itc()); + + /* + * Subtle stuff here: we _could_ unwind through the switch_stack frame but we + * don't want to do that because it would be slow as each preserved register would + * have to be processed. Instead, what we do here is zero out the frame info and + * start the unwind process at the function that created the switch_stack frame. + * When a preserved value in switch_stack needs to be accessed, run_script() will + * initialize the appropriate pointer on demand. + */ + memset(info, 0, sizeof(*info)); + + rbslimit = (unsigned long) t + IA64_RBS_OFFSET; + stklimit = (unsigned long) t + IA64_STK_OFFSET; + + rbstop = sw->ar_bspstore; + if (rbstop > stklimit || rbstop < rbslimit) + rbstop = rbslimit; + + if (stktop <= rbstop) + stktop = rbstop; + if (stktop > stklimit) + stktop = stklimit; + + info->regstk.limit = rbslimit; + info->regstk.top = rbstop; + info->memstk.limit = stklimit; + info->memstk.top = stktop; + info->task = t; + info->sw = sw; + info->sp = info->psp = stktop; + info->pr = sw->pr; + UNW_DPRINT(3, "unwind.%s:\n" + " task 0x%lx\n" + " rbs = [0x%lx-0x%lx)\n" + " stk = [0x%lx-0x%lx)\n" + " pr 0x%lx\n" + " sw 0x%lx\n" + " sp 0x%lx\n", + __func__, (unsigned long) t, rbslimit, rbstop, stktop, stklimit, + info->pr, (unsigned long) info->sw, info->sp); + STAT(unw.stat.api.init_time += ia64_get_itc() - start; local_irq_restore(flags)); +} + +void +unw_init_frame_info (struct unw_frame_info *info, struct task_struct *t, struct switch_stack *sw) +{ + unsigned long sol; + + init_frame_info(info, t, sw, (unsigned long) (sw + 1) - 16); + info->cfm_loc = &sw->ar_pfs; + sol = (*info->cfm_loc >> 7) & 0x7f; + info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->regstk.top, -sol); + info->ip = sw->b0; + UNW_DPRINT(3, "unwind.%s:\n" + " bsp 0x%lx\n" + " sol 0x%lx\n" + " ip 0x%lx\n", + __func__, info->bsp, sol, info->ip); + find_save_locs(info); +} + +EXPORT_SYMBOL(unw_init_frame_info); + +void +unw_init_from_blocked_task (struct unw_frame_info *info, struct task_struct *t) +{ + struct switch_stack *sw = (struct switch_stack *) (t->thread.ksp + 16); + + UNW_DPRINT(1, "unwind.%s\n", __func__); + unw_init_frame_info(info, t, sw); +} +EXPORT_SYMBOL(unw_init_from_blocked_task); + +static void +init_unwind_table (struct unw_table *table, const char *name, unsigned long segment_base, + unsigned long gp, const void *table_start, const void *table_end) +{ + const struct unw_table_entry *start = table_start, *end = table_end; + + table->name = name; + table->segment_base = segment_base; + table->gp = gp; + table->start = segment_base + start[0].start_offset; + table->end = segment_base + end[-1].end_offset; + table->array = start; + table->length = end - start; +} + +void * +unw_add_unwind_table (const char *name, unsigned long segment_base, unsigned long gp, + const void *table_start, const void *table_end) +{ + const struct unw_table_entry *start = table_start, *end = table_end; + struct unw_table *table; + unsigned long flags; + + if (end - start <= 0) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to insert empty unwind table\n", + __func__); + return NULL; + } + + table = kmalloc(sizeof(*table), GFP_USER); + if (!table) + return NULL; + + init_unwind_table(table, name, segment_base, gp, table_start, table_end); + + spin_lock_irqsave(&unw.lock, flags); + { + /* keep kernel unwind table at the front (it's searched most commonly): */ + table->next = unw.tables->next; + unw.tables->next = table; + } + spin_unlock_irqrestore(&unw.lock, flags); + + return table; +} + +void +unw_remove_unwind_table (void *handle) +{ + struct unw_table *table, *prev; + struct unw_script *tmp; + unsigned long flags; + long index; + + if (!handle) { + UNW_DPRINT(0, "unwind.%s: ignoring attempt to remove non-existent unwind table\n", + __func__); + return; + } + + table = handle; + if (table == &unw.kernel_table) { + UNW_DPRINT(0, "unwind.%s: sorry, freeing the kernel's unwind table is a " + "no-can-do!\n", __func__); + return; + } + + spin_lock_irqsave(&unw.lock, flags); + { + /* first, delete the table: */ + + for (prev = (struct unw_table *) &unw.tables; prev; prev = prev->next) + if (prev->next == table) + break; + if (!prev) { + UNW_DPRINT(0, "unwind.%s: failed to find unwind table %p\n", + __func__, (void *) table); + spin_unlock_irqrestore(&unw.lock, flags); + return; + } + prev->next = table->next; + } + spin_unlock_irqrestore(&unw.lock, flags); + + /* next, remove hash table entries for this table */ + + for (index = 0; index < UNW_HASH_SIZE; ++index) { + tmp = unw.cache + unw.hash[index]; + if (unw.hash[index] >= UNW_CACHE_SIZE + || tmp->ip < table->start || tmp->ip >= table->end) + continue; + + write_lock(&tmp->lock); + { + if (tmp->ip >= table->start && tmp->ip < table->end) { + unw.hash[index] = tmp->coll_chain; + tmp->ip = 0; + } + } + write_unlock(&tmp->lock); + } + + kfree(table); +} + +static int __init +create_gate_table (void) +{ + const struct unw_table_entry *entry, *start, *end; + unsigned long *lp, segbase = GATE_ADDR; + size_t info_size, size; + char *info; + Elf64_Phdr *punw = NULL, *phdr = (Elf64_Phdr *) (GATE_ADDR + GATE_EHDR->e_phoff); + int i; + + for (i = 0; i < GATE_EHDR->e_phnum; ++i, ++phdr) + if (phdr->p_type == PT_IA_64_UNWIND) { + punw = phdr; + break; + } + + if (!punw) { + printk("%s: failed to find gate DSO's unwind table!\n", __func__); + return 0; + } + + start = (const struct unw_table_entry *) punw->p_vaddr; + end = (struct unw_table_entry *) ((char *) start + punw->p_memsz); + size = 0; + + unw_add_unwind_table("linux-gate.so", segbase, 0, start, end); + + for (entry = start; entry < end; ++entry) + size += 3*8 + 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset)); + size += 8; /* reserve space for "end of table" marker */ + + unw.gate_table = kmalloc(size, GFP_KERNEL); + if (!unw.gate_table) { + unw.gate_table_size = 0; + printk(KERN_ERR "%s: unable to create unwind data for gate page!\n", __func__); + return 0; + } + unw.gate_table_size = size; + + lp = unw.gate_table; + info = (char *) unw.gate_table + size; + + for (entry = start; entry < end; ++entry, lp += 3) { + info_size = 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset)); + info -= info_size; + memcpy(info, (char *) segbase + entry->info_offset, info_size); + + lp[0] = segbase + entry->start_offset; /* start */ + lp[1] = segbase + entry->end_offset; /* end */ + lp[2] = info - (char *) unw.gate_table; /* info */ + } + *lp = 0; /* end-of-table marker */ + return 0; +} + +__initcall(create_gate_table); + +void __init +unw_init (void) +{ + extern char __gp[]; + extern void unw_hash_index_t_is_too_narrow (void); + long i, off; + + if (8*sizeof(unw_hash_index_t) < UNW_LOG_HASH_SIZE) + unw_hash_index_t_is_too_narrow(); + + unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(CALLER_UNAT); + unw.sw_off[unw.preg_index[UNW_REG_BSPSTORE]] = SW(AR_BSPSTORE); + unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS); + unw.sw_off[unw.preg_index[UNW_REG_RP]] = SW(B0); + unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(CALLER_UNAT); + unw.sw_off[unw.preg_index[UNW_REG_PR]] = SW(PR); + unw.sw_off[unw.preg_index[UNW_REG_LC]] = SW(AR_LC); + unw.sw_off[unw.preg_index[UNW_REG_FPSR]] = SW(AR_FPSR); + for (i = UNW_REG_R4, off = SW(R4); i <= UNW_REG_R7; ++i, off += 8) + unw.sw_off[unw.preg_index[i]] = off; + for (i = UNW_REG_B1, off = SW(B1); i <= UNW_REG_B5; ++i, off += 8) + unw.sw_off[unw.preg_index[i]] = off; + for (i = UNW_REG_F2, off = SW(F2); i <= UNW_REG_F5; ++i, off += 16) + unw.sw_off[unw.preg_index[i]] = off; + for (i = UNW_REG_F16, off = SW(F16); i <= UNW_REG_F31; ++i, off += 16) + unw.sw_off[unw.preg_index[i]] = off; + + for (i = 0; i < UNW_CACHE_SIZE; ++i) { + if (i > 0) + unw.cache[i].lru_chain = (i - 1); + unw.cache[i].coll_chain = -1; + rwlock_init(&unw.cache[i].lock); + } + unw.lru_head = UNW_CACHE_SIZE - 1; + unw.lru_tail = 0; + + init_unwind_table(&unw.kernel_table, "kernel", KERNEL_START, (unsigned long) __gp, + __start_unwind, __end_unwind); +} + +/* + * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED + * + * This system call has been deprecated. The new and improved way to get + * at the kernel's unwind info is via the gate DSO. The address of the + * ELF header for this DSO is passed to user-level via AT_SYSINFO_EHDR. + * + * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED + * + * This system call copies the unwind data into the buffer pointed to by BUF and returns + * the size of the unwind data. If BUF_SIZE is smaller than the size of the unwind data + * or if BUF is NULL, nothing is copied, but the system call still returns the size of the + * unwind data. + * + * The first portion of the unwind data contains an unwind table and rest contains the + * associated unwind info (in no particular order). The unwind table consists of a table + * of entries of the form: + * + * u64 start; (64-bit address of start of function) + * u64 end; (64-bit address of start of function) + * u64 info; (BUF-relative offset to unwind info) + * + * The end of the unwind table is indicated by an entry with a START address of zero. + * + * Please see the IA-64 Software Conventions and Runtime Architecture manual for details + * on the format of the unwind info. + * + * ERRORS + * EFAULT BUF points outside your accessible address space. + */ +asmlinkage long +sys_getunwind (void __user *buf, size_t buf_size) +{ + if (buf && buf_size >= unw.gate_table_size) + if (copy_to_user(buf, unw.gate_table, unw.gate_table_size) != 0) + return -EFAULT; + return unw.gate_table_size; +} |