diff options
author | Helge Deller <deller@gmx.de> | 2018-08-05 00:03:29 +0200 |
---|---|---|
committer | Helge Deller <deller@gmx.de> | 2018-08-13 09:54:17 +0200 |
commit | c8921d72e390cb6fca3fb2b0c2badfda851647eb (patch) | |
tree | 8c6aec1a9405da9caad70088a7dfd910b71b6675 /arch/parisc/kernel | |
parent | 3b885ac1dc35b87a39ee176a6c7e2af9c789d8b8 (diff) | |
download | linux-stable-c8921d72e390cb6fca3fb2b0c2badfda851647eb.tar.gz linux-stable-c8921d72e390cb6fca3fb2b0c2badfda851647eb.tar.bz2 linux-stable-c8921d72e390cb6fca3fb2b0c2badfda851647eb.zip |
parisc: Fix and improve kernel stack unwinding
This patchset fixes and improves stack unwinding a lot:
1. Show backward stack traces with up to 30 callsites
2. Add callinfo to ENTRY_CFI() such that every assembler function will get an
entry in the unwind table
3. Use constants instead of numbers in call_on_stack()
4. Do not depend on CONFIG_KALLSYMS to generate backtraces.
5. Speed up backtrace generation
Make sure you have this patch to GNU as installed:
https://sourceware.org/ml/binutils/2018-07/msg00474.html
Without this patch, unwind info in the kernel is often wrong for various
functions.
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/kernel')
-rw-r--r-- | arch/parisc/kernel/entry.S | 53 | ||||
-rw-r--r-- | arch/parisc/kernel/pacache.S | 125 | ||||
-rw-r--r-- | arch/parisc/kernel/process.c | 2 | ||||
-rw-r--r-- | arch/parisc/kernel/real2.S | 6 | ||||
-rw-r--r-- | arch/parisc/kernel/traps.c | 2 | ||||
-rw-r--r-- | arch/parisc/kernel/unwind.c | 89 |
6 files changed, 72 insertions, 205 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 1b4732e20137..c7508f5717fb 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -766,7 +766,6 @@ END(fault_vector_11) #endif /* Fault vector is separately protected and *must* be on its own page */ .align PAGE_SIZE -ENTRY(end_fault_vector) .import handle_interruption,code .import do_cpu_irq_mask,code @@ -778,7 +777,6 @@ ENTRY(end_fault_vector) */ ENTRY_CFI(ret_from_kernel_thread) - /* Call schedule_tail first though */ BL schedule_tail, %r2 nop @@ -817,8 +815,9 @@ ENTRY_CFI(_switch_to) LDREG TASK_THREAD_INFO(%r25), %r25 bv %r0(%r2) mtctl %r25,%cr30 +ENDPROC_CFI(_switch_to) -_switch_to_ret: +ENTRY_CFI(_switch_to_ret) mtctl %r0, %cr0 /* Needed for single stepping */ callee_rest callee_rest_float @@ -826,7 +825,7 @@ _switch_to_ret: LDREG -RP_OFFSET(%r30), %r2 bv %r0(%r2) copy %r26, %r28 -ENDPROC_CFI(_switch_to) +ENDPROC_CFI(_switch_to_ret) /* * Common rfi return path for interruptions, kernel execve, and @@ -887,12 +886,14 @@ ENTRY_CFI(syscall_exit_rfi) STREG %r19,PT_SR5(%r16) STREG %r19,PT_SR6(%r16) STREG %r19,PT_SR7(%r16) +ENDPROC_CFI(syscall_exit_rfi) -intr_return: +ENTRY_CFI(intr_return) /* check for reschedule */ mfctl %cr30,%r1 LDREG TI_FLAGS(%r1),%r19 /* sched.h: TIF_NEED_RESCHED */ bb,<,n %r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */ +ENDPROC_CFI(intr_return) .import do_notify_resume,code intr_check_sig: @@ -1048,7 +1049,6 @@ intr_extint: b do_cpu_irq_mask ldo R%intr_return(%r2), %r2 /* return to intr_return, not here */ -ENDPROC_CFI(syscall_exit_rfi) /* Generic interruptions (illegal insn, unaligned, page fault, etc) */ @@ -1999,12 +1999,9 @@ ENDPROC_CFI(syscall_exit) .align L1_CACHE_BYTES .globl mcount .type mcount, @function -ENTRY(mcount) +ENTRY_CFI(mcount, caller) _mcount: .export _mcount,data - .proc - .callinfo caller,frame=0 - .entry /* * The 64bit mcount() function pointer needs 4 dwords, of which the * first two are free. We optimize it here and put 2 instructions for @@ -2026,18 +2023,13 @@ ftrace_stub: .dword mcount .dword 0 /* code in head.S puts value of global gp here */ #endif - .exit - .procend -ENDPROC(mcount) +ENDPROC_CFI(mcount) #ifdef CONFIG_FUNCTION_GRAPH_TRACER .align 8 .globl return_to_handler .type return_to_handler, @function -ENTRY_CFI(return_to_handler) - .proc - .callinfo caller,frame=FRAME_SIZE - .entry +ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE) .export parisc_return_to_handler,data parisc_return_to_handler: copy %r3,%r1 @@ -2076,8 +2068,6 @@ parisc_return_to_handler: bv %r0(%rp) #endif LDREGM -FRAME_SIZE(%sp),%r3 - .exit - .procend ENDPROC_CFI(return_to_handler) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ @@ -2087,31 +2077,30 @@ ENDPROC_CFI(return_to_handler) #ifdef CONFIG_IRQSTACKS /* void call_on_stack(unsigned long param1, void *func, unsigned long new_stack) */ -ENTRY_CFI(call_on_stack) +ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP) copy %sp, %r1 /* Regarding the HPPA calling conventions for function pointers, we assume the PIC register is not changed across call. For CONFIG_64BIT, the argument pointer is left to point at the argument region allocated for the call to call_on_stack. */ + + /* Switch to new stack. We allocate two frames. */ + ldo 2*FRAME_SIZE(%arg2), %sp # ifdef CONFIG_64BIT - /* Switch to new stack. We allocate two 128 byte frames. */ - ldo 256(%arg2), %sp /* Save previous stack pointer and return pointer in frame marker */ - STREG %rp, -144(%sp) + STREG %rp, -FRAME_SIZE-RP_OFFSET(%sp) /* Calls always use function descriptor */ LDREG 16(%arg1), %arg1 bve,l (%arg1), %rp - STREG %r1, -136(%sp) - LDREG -144(%sp), %rp + STREG %r1, -FRAME_SIZE-REG_SZ(%sp) + LDREG -FRAME_SIZE-RP_OFFSET(%sp), %rp bve (%rp) - LDREG -136(%sp), %sp + LDREG -FRAME_SIZE-REG_SZ(%sp), %sp # else - /* Switch to new stack. We allocate two 64 byte frames. */ - ldo 128(%arg2), %sp /* Save previous stack pointer and return pointer in frame marker */ - STREG %r1, -68(%sp) - STREG %rp, -84(%sp) + STREG %r1, -FRAME_SIZE-REG_SZ(%sp) + STREG %rp, -FRAME_SIZE-RP_OFFSET(%sp) /* Calls use function descriptor if PLABEL bit is set */ bb,>=,n %arg1, 30, 1f depwi 0,31,2, %arg1 @@ -2119,9 +2108,9 @@ ENTRY_CFI(call_on_stack) 1: be,l 0(%sr4,%arg1), %sr0, %r31 copy %r31, %rp - LDREG -84(%sp), %rp + LDREG -FRAME_SIZE-RP_OFFSET(%sp), %rp bv (%rp) - LDREG -68(%sp), %sp + LDREG -FRAME_SIZE-REG_SZ(%sp), %sp # endif /* CONFIG_64BIT */ ENDPROC_CFI(call_on_stack) #endif /* CONFIG_IRQSTACKS */ diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S index 97451e67d35b..f33bf2d306d6 100644 --- a/arch/parisc/kernel/pacache.S +++ b/arch/parisc/kernel/pacache.S @@ -44,10 +44,6 @@ .align 16 ENTRY_CFI(flush_tlb_all_local) - .proc - .callinfo NO_CALLS - .entry - /* * The pitlbe and pdtlbe instructions should only be used to * flush the entire tlb. Also, there needs to be no intervening @@ -189,18 +185,11 @@ fdtdone: 2: bv %r0(%r2) nop - - .exit - .procend ENDPROC_CFI(flush_tlb_all_local) .import cache_info,data ENTRY_CFI(flush_instruction_cache_local) - .proc - .callinfo NO_CALLS - .entry - load32 cache_info, %r1 /* Flush Instruction Cache */ @@ -256,18 +245,11 @@ fisync: mtsm %r22 /* restore I-bit */ bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_instruction_cache_local) .import cache_info, data ENTRY_CFI(flush_data_cache_local) - .proc - .callinfo NO_CALLS - .entry - load32 cache_info, %r1 /* Flush Data Cache */ @@ -324,9 +306,6 @@ fdsync: mtsm %r22 /* restore I-bit */ bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_data_cache_local) /* Macros to serialize TLB purge operations on SMP. */ @@ -362,10 +341,6 @@ ENDPROC_CFI(flush_data_cache_local) /* Clear page using kernel mapping. */ ENTRY_CFI(clear_page_asm) - .proc - .callinfo NO_CALLS - .entry - #ifdef CONFIG_64BIT /* Unroll the loop. */ @@ -424,18 +399,11 @@ ENTRY_CFI(clear_page_asm) #endif bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(clear_page_asm) /* Copy page using kernel mapping. */ ENTRY_CFI(copy_page_asm) - .proc - .callinfo NO_CALLS - .entry - #ifdef CONFIG_64BIT /* PA8x00 CPUs can consume 2 loads or 1 store per cycle. * Unroll the loop by hand and arrange insn appropriately. @@ -542,9 +510,6 @@ ENTRY_CFI(copy_page_asm) #endif bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(copy_page_asm) /* @@ -598,10 +563,6 @@ ENDPROC_CFI(copy_page_asm) */ ENTRY_CFI(copy_user_page_asm) - .proc - .callinfo NO_CALLS - .entry - /* Convert virtual `to' and `from' addresses to physical addresses. Move `from' physical address to non shadowed register. */ ldil L%(__PAGE_OFFSET), %r1 @@ -750,16 +711,9 @@ ENTRY_CFI(copy_user_page_asm) bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(copy_user_page_asm) ENTRY_CFI(clear_user_page_asm) - .proc - .callinfo NO_CALLS - .entry - tophys_r1 %r26 ldil L%(TMPALIAS_MAP_START), %r28 @@ -836,16 +790,9 @@ ENTRY_CFI(clear_user_page_asm) bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(clear_user_page_asm) ENTRY_CFI(flush_dcache_page_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%(TMPALIAS_MAP_START), %r28 #ifdef CONFIG_64BIT #if (TMPALIAS_MAP_START >= 0x80000000) @@ -903,16 +850,9 @@ ENTRY_CFI(flush_dcache_page_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_dcache_page_asm) ENTRY_CFI(flush_icache_page_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%(TMPALIAS_MAP_START), %r28 #ifdef CONFIG_64BIT #if (TMPALIAS_MAP_START >= 0x80000000) @@ -977,16 +917,9 @@ ENTRY_CFI(flush_icache_page_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_icache_page_asm) ENTRY_CFI(flush_kernel_dcache_page_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%dcache_stride, %r1 ldw R%dcache_stride(%r1), %r23 @@ -1020,16 +953,9 @@ ENTRY_CFI(flush_kernel_dcache_page_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_kernel_dcache_page_asm) ENTRY_CFI(purge_kernel_dcache_page_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%dcache_stride, %r1 ldw R%dcache_stride(%r1), %r23 @@ -1062,16 +988,9 @@ ENTRY_CFI(purge_kernel_dcache_page_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(purge_kernel_dcache_page_asm) ENTRY_CFI(flush_user_dcache_range_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%dcache_stride, %r1 ldw R%dcache_stride(%r1), %r23 ldo -1(%r23), %r21 @@ -1083,16 +1002,9 @@ ENTRY_CFI(flush_user_dcache_range_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_user_dcache_range_asm) ENTRY_CFI(flush_kernel_dcache_range_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%dcache_stride, %r1 ldw R%dcache_stride(%r1), %r23 ldo -1(%r23), %r21 @@ -1105,16 +1017,9 @@ ENTRY_CFI(flush_kernel_dcache_range_asm) syncdma bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_kernel_dcache_range_asm) ENTRY_CFI(purge_kernel_dcache_range_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%dcache_stride, %r1 ldw R%dcache_stride(%r1), %r23 ldo -1(%r23), %r21 @@ -1127,16 +1032,9 @@ ENTRY_CFI(purge_kernel_dcache_range_asm) syncdma bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(purge_kernel_dcache_range_asm) ENTRY_CFI(flush_user_icache_range_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%icache_stride, %r1 ldw R%icache_stride(%r1), %r23 ldo -1(%r23), %r21 @@ -1148,16 +1046,9 @@ ENTRY_CFI(flush_user_icache_range_asm) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_user_icache_range_asm) ENTRY_CFI(flush_kernel_icache_page) - .proc - .callinfo NO_CALLS - .entry - ldil L%icache_stride, %r1 ldw R%icache_stride(%r1), %r23 @@ -1191,16 +1082,9 @@ ENTRY_CFI(flush_kernel_icache_page) sync bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(flush_kernel_icache_page) ENTRY_CFI(flush_kernel_icache_range_asm) - .proc - .callinfo NO_CALLS - .entry - ldil L%icache_stride, %r1 ldw R%icache_stride(%r1), %r23 ldo -1(%r23), %r21 @@ -1212,8 +1096,6 @@ ENTRY_CFI(flush_kernel_icache_range_asm) sync bv %r0(%r2) nop - .exit - .procend ENDPROC_CFI(flush_kernel_icache_range_asm) __INIT @@ -1223,10 +1105,6 @@ ENDPROC_CFI(flush_kernel_icache_range_asm) */ .align 256 ENTRY_CFI(disable_sr_hashing_asm) - .proc - .callinfo NO_CALLS - .entry - /* * Switch to real mode */ @@ -1308,9 +1186,6 @@ srdis_done: 2: bv %r0(%r2) nop - .exit - - .procend ENDPROC_CFI(disable_sr_hashing_asm) .end diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index b931745815e0..eb39e7e380d7 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -302,7 +302,7 @@ get_wchan(struct task_struct *p) ip = info.ip; if (!in_sched_functions(ip)) return ip; - } while (count++ < 16); + } while (count++ < MAX_UNWIND_ENTRIES); return 0; } diff --git a/arch/parisc/kernel/real2.S b/arch/parisc/kernel/real2.S index cc9963421a19..2b16d8d6598f 100644 --- a/arch/parisc/kernel/real2.S +++ b/arch/parisc/kernel/real2.S @@ -35,12 +35,6 @@ real32_stack: real64_stack: .block 8192 -#ifdef CONFIG_64BIT -# define REG_SZ 8 -#else -# define REG_SZ 4 -#endif - #define N_SAVED_REGS 9 save_cr_space: diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index 4309ad31a874..318815212518 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -172,7 +172,7 @@ static void do_show_stack(struct unwind_frame_info *info) int i = 1; printk(KERN_CRIT "Backtrace:\n"); - while (i <= 16) { + while (i <= MAX_UNWIND_ENTRIES) { if (unwind_once(info) < 0 || info->ip == 0) break; diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c index a4b430f440a9..5cdf13069dd9 100644 --- a/arch/parisc/kernel/unwind.c +++ b/arch/parisc/kernel/unwind.c @@ -13,7 +13,6 @@ #include <linux/init.h> #include <linux/sched.h> #include <linux/slab.h> -#include <linux/kallsyms.h> #include <linux/sort.h> #include <linux/uaccess.h> @@ -117,7 +116,8 @@ unwind_table_init(struct unwind_table *table, const char *name, for (; start <= end; start++) { if (start < end && start->region_end > (start+1)->region_start) { - printk("WARNING: Out of order unwind entry! %p and %p\n", start, start+1); + pr_warn("Out of order unwind entry! %px and %px\n", + start, start+1); } start->region_start += base_addr; @@ -203,25 +203,60 @@ int __init unwind_init(void) return 0; } -#ifdef CONFIG_64BIT -#define get_func_addr(fptr) fptr[2] -#else -#define get_func_addr(fptr) fptr[0] -#endif - static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int frame_size) { - extern void handle_interruption(int, struct pt_regs *); - static unsigned long *hi = (unsigned long *)&handle_interruption; - - if (pc == get_func_addr(hi)) { + /* + * We have to use void * instead of a function pointer, because + * function pointers aren't a pointer to the function on 64-bit. + * Make them const so the compiler knows they live in .text + */ + extern void * const handle_interruption; + extern void * const ret_from_kernel_thread; + extern void * const syscall_exit; + extern void * const intr_return; + extern void * const _switch_to_ret; +#ifdef CONFIG_IRQSTACKS + extern void * const call_on_stack; +#endif /* CONFIG_IRQSTACKS */ + + if (pc == (unsigned long) &handle_interruption) { struct pt_regs *regs = (struct pt_regs *)(info->sp - frame_size - PT_SZ_ALGN); dbg("Unwinding through handle_interruption()\n"); info->prev_sp = regs->gr[30]; info->prev_ip = regs->iaoq[0]; + return 1; + } + + if (pc == (unsigned long) &ret_from_kernel_thread || + pc == (unsigned long) &syscall_exit) { + info->prev_sp = info->prev_ip = 0; + return 1; + } + + if (pc == (unsigned long) &intr_return) { + struct pt_regs *regs; + + dbg("Found intr_return()\n"); + regs = (struct pt_regs *)(info->sp - PT_SZ_ALGN); + info->prev_sp = regs->gr[30]; + info->prev_ip = regs->iaoq[0]; + info->rp = regs->gr[2]; + return 1; + } + + if (pc == (unsigned long) &_switch_to_ret) { + info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE; + info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET); + return 1; + } +#ifdef CONFIG_IRQSTACKS + if (pc == (unsigned long) &call_on_stack) { + info->prev_sp = *(unsigned long *)(info->sp - FRAME_SIZE - REG_SZ); + info->prev_ip = *(unsigned long *)(info->sp - FRAME_SIZE - RP_OFFSET); return 1; } +#endif return 0; } @@ -238,34 +273,8 @@ static void unwind_frame_regs(struct unwind_frame_info *info) if (e == NULL) { unsigned long sp; - dbg("Cannot find unwind entry for 0x%lx; forced unwinding\n", info->ip); - -#ifdef CONFIG_KALLSYMS - /* Handle some frequent special cases.... */ - { - char symname[KSYM_NAME_LEN]; - char *modname; - - kallsyms_lookup(info->ip, NULL, NULL, &modname, - symname); - - dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname); - - if (strcmp(symname, "_switch_to_ret") == 0) { - info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE; - info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET); - dbg("_switch_to_ret @ %lx - setting " - "prev_sp=%lx prev_ip=%lx\n", - info->ip, info->prev_sp, - info->prev_ip); - return; - } else if (strcmp(symname, "ret_from_kernel_thread") == 0 || - strcmp(symname, "syscall_exit") == 0) { - info->prev_ip = info->prev_sp = 0; - return; - } - } -#endif + dbg("Cannot find unwind entry for %pS; forced unwinding\n", + (void *) info->ip); /* Since we are doing the unwinding blind, we don't know if we are adjusting the stack correctly or extracting the rp |