2019-05-27 09:55:01 +03:00
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/* SPDX-License-Identifier: GPL-2.0-or-later */
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2017-04-25 16:55:54 +03:00
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/*
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* Split from ftrace_64.S
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*/
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#include <linux/magic.h>
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#include <asm/ppc_asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/ftrace.h>
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#include <asm/ppc-opcode.h>
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#include <asm/export.h>
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#include <asm/thread_info.h>
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#include <asm/bug.h>
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#include <asm/ptrace.h>
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/*
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*
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2018-04-19 10:04:09 +03:00
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* ftrace_caller()/ftrace_regs_caller() is the function that replaces _mcount()
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* when ftrace is active.
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2017-04-25 16:55:54 +03:00
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*
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* We arrive here after a function A calls function B, and we are the trace
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* function for B. When we enter r1 points to A's stack frame, B has not yet
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* had a chance to allocate one yet.
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*
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* Additionally r2 may point either to the TOC for A, or B, depending on
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* whether B did a TOC setup sequence before calling us.
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*
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* On entry the LR points back to the _mcount() call site, and r0 holds the
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* saved LR as it was on entry to B, ie. the original return address at the
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* call site in A.
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*
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* Our job is to save the register state into a struct pt_regs (on the stack)
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* and then arrange for the ftrace function to be called.
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*/
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2018-04-19 10:04:09 +03:00
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_GLOBAL(ftrace_regs_caller)
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2017-04-25 16:55:54 +03:00
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/* Save the original return address in A's stack frame */
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std r0,LRSAVE(r1)
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/* Create our stack frame + pt_regs */
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stdu r1,-SWITCH_FRAME_SIZE(r1)
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/* Save all gprs to pt_regs */
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2017-06-01 13:48:16 +03:00
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SAVE_GPR(0, r1)
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SAVE_10GPRS(2, r1)
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2018-04-19 10:04:00 +03:00
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/* Ok to continue? */
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lbz r3, PACA_FTRACE_ENABLED(r13)
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cmpdi r3, 0
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beq ftrace_no_trace
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2017-06-01 13:48:16 +03:00
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SAVE_10GPRS(12, r1)
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SAVE_10GPRS(22, r1)
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/* Save previous stack pointer (r1) */
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addi r8, r1, SWITCH_FRAME_SIZE
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std r8, GPR1(r1)
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2017-04-25 16:55:54 +03:00
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/* Load special regs for save below */
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mfmsr r8
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mfctr r9
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mfxer r10
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mfcr r11
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/* Get the _mcount() call site out of LR */
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mflr r7
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/* Save it as pt_regs->nip */
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std r7, _NIP(r1)
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/* Save the read LR in pt_regs->link */
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std r0, _LINK(r1)
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/* Save callee's TOC in the ABI compliant location */
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std r2, 24(r1)
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ld r2,PACATOC(r13) /* get kernel TOC in r2 */
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addis r3,r2,function_trace_op@toc@ha
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addi r3,r3,function_trace_op@toc@l
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ld r5,0(r3)
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#ifdef CONFIG_LIVEPATCH
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mr r14,r7 /* remember old NIP */
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#endif
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/* Calculate ip from nip-4 into r3 for call below */
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subi r3, r7, MCOUNT_INSN_SIZE
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/* Put the original return address in r4 as parent_ip */
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mr r4, r0
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/* Save special regs */
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std r8, _MSR(r1)
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std r9, _CTR(r1)
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std r10, _XER(r1)
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std r11, _CCR(r1)
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/* Load &pt_regs in r6 for call below */
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addi r6, r1 ,STACK_FRAME_OVERHEAD
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/* ftrace_call(r3, r4, r5, r6) */
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2018-04-19 10:04:09 +03:00
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.globl ftrace_regs_call
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ftrace_regs_call:
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2017-04-25 16:55:54 +03:00
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bl ftrace_stub
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nop
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2018-06-19 19:07:32 +03:00
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/* Load ctr with the possibly modified NIP */
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ld r3, _NIP(r1)
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mtctr r3
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2017-04-25 16:55:54 +03:00
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#ifdef CONFIG_LIVEPATCH
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2018-06-19 19:07:32 +03:00
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cmpd r14, r3 /* has NIP been altered? */
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2017-04-25 16:55:54 +03:00
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#endif
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/* Restore gprs */
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2017-06-01 13:48:16 +03:00
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REST_GPR(0,r1)
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REST_10GPRS(2,r1)
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REST_10GPRS(12,r1)
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REST_10GPRS(22,r1)
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2017-04-25 16:55:54 +03:00
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/* Restore possibly modified LR */
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ld r0, _LINK(r1)
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mtlr r0
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/* Restore callee's TOC */
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ld r2, 24(r1)
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/* Pop our stack frame */
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addi r1, r1, SWITCH_FRAME_SIZE
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#ifdef CONFIG_LIVEPATCH
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2018-06-19 19:07:32 +03:00
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/* Based on the cmpd above, if the NIP was altered handle livepatch */
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2017-04-25 16:55:54 +03:00
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bne- livepatch_handler
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#endif
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2018-04-19 10:04:09 +03:00
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ftrace_caller_common:
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2017-04-25 16:55:54 +03:00
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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.globl ftrace_graph_call
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ftrace_graph_call:
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b ftrace_graph_stub
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_GLOBAL(ftrace_graph_stub)
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#endif
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bctr /* jump after _mcount site */
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_GLOBAL(ftrace_stub)
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blr
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2018-04-19 10:04:00 +03:00
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ftrace_no_trace:
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mflr r3
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mtctr r3
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REST_GPR(3, r1)
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addi r1, r1, SWITCH_FRAME_SIZE
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mtlr r0
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bctr
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2018-04-19 10:04:09 +03:00
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_GLOBAL(ftrace_caller)
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/* Save the original return address in A's stack frame */
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std r0, LRSAVE(r1)
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/* Create our stack frame + pt_regs */
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stdu r1, -SWITCH_FRAME_SIZE(r1)
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/* Save all gprs to pt_regs */
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SAVE_8GPRS(3, r1)
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lbz r3, PACA_FTRACE_ENABLED(r13)
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cmpdi r3, 0
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beq ftrace_no_trace
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/* Get the _mcount() call site out of LR */
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mflr r7
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std r7, _NIP(r1)
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/* Save callee's TOC in the ABI compliant location */
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std r2, 24(r1)
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ld r2, PACATOC(r13) /* get kernel TOC in r2 */
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addis r3, r2, function_trace_op@toc@ha
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addi r3, r3, function_trace_op@toc@l
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ld r5, 0(r3)
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/* Calculate ip from nip-4 into r3 for call below */
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subi r3, r7, MCOUNT_INSN_SIZE
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/* Put the original return address in r4 as parent_ip */
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mr r4, r0
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/* Set pt_regs to NULL */
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li r6, 0
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/* ftrace_call(r3, r4, r5, r6) */
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.globl ftrace_call
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ftrace_call:
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bl ftrace_stub
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nop
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ld r3, _NIP(r1)
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mtctr r3
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/* Restore gprs */
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REST_8GPRS(3,r1)
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/* Restore callee's TOC */
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ld r2, 24(r1)
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/* Pop our stack frame */
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addi r1, r1, SWITCH_FRAME_SIZE
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/* Reload original LR */
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ld r0, LRSAVE(r1)
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mtlr r0
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/* Handle function_graph or go back */
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b ftrace_caller_common
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2017-04-25 16:55:54 +03:00
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#ifdef CONFIG_LIVEPATCH
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/*
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* This function runs in the mcount context, between two functions. As
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* such it can only clobber registers which are volatile and used in
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* function linkage.
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*
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* We get here when a function A, calls another function B, but B has
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* been live patched with a new function C.
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*
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* On entry:
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* - we have no stack frame and can not allocate one
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* - LR points back to the original caller (in A)
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* - CTR holds the new NIP in C
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powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
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* - r0, r11 & r12 are free
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2017-04-25 16:55:54 +03:00
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*/
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livepatch_handler:
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2019-01-12 12:55:50 +03:00
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ld r12, PACA_THREAD_INFO(r13)
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2017-04-25 16:55:54 +03:00
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/* Allocate 3 x 8 bytes */
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powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
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ld r11, TI_livepatch_sp(r12)
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addi r11, r11, 24
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std r11, TI_livepatch_sp(r12)
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2017-04-25 16:55:54 +03:00
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/* Save toc & real LR on livepatch stack */
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powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
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std r2, -24(r11)
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2017-04-25 16:55:54 +03:00
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mflr r12
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powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
std r12, -16(r11)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
|
|
|
|
/* Store stack end marker */
|
|
|
|
|
lis r12, STACK_END_MAGIC@h
|
|
|
|
|
ori r12, r12, STACK_END_MAGIC@l
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
std r12, -8(r11)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
|
|
|
|
/* Put ctr in r12 for global entry and branch there */
|
|
|
|
|
mfctr r12
|
|
|
|
|
bctrl
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Now we are returning from the patched function to the original
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
* caller A. We are free to use r11, r12 and we can use r2 until we
|
2017-04-25 16:55:54 +03:00
|
|
|
* restore it.
|
|
|
|
|
*/
|
|
|
|
|
|
2019-01-12 12:55:50 +03:00
|
|
|
ld r12, PACA_THREAD_INFO(r13)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
ld r11, TI_livepatch_sp(r12)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
|
|
|
|
/* Check stack marker hasn't been trashed */
|
|
|
|
|
lis r2, STACK_END_MAGIC@h
|
|
|
|
|
ori r2, r2, STACK_END_MAGIC@l
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
ld r12, -8(r11)
|
2017-04-25 16:55:54 +03:00
|
|
|
1: tdne r12, r2
|
|
|
|
|
EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0
|
|
|
|
|
|
|
|
|
|
/* Restore LR & toc from livepatch stack */
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
ld r12, -16(r11)
|
2017-04-25 16:55:54 +03:00
|
|
|
mtlr r12
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
ld r2, -24(r11)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
|
|
|
|
/* Pop livepatch stack frame */
|
2019-01-12 12:55:50 +03:00
|
|
|
ld r12, PACA_THREAD_INFO(r13)
|
powerpc/livepatch: Fix livepatch stack access
While running stress test with livepatch module loaded, kernel bug was
triggered.
cpu 0x5: Vector: 400 (Instruction Access) at [c0000000eb9d3b60]
5:mon> t
[c0000000eb9d3de0] c0000000eb9d3e30 (unreliable)
[c0000000eb9d3e30] c000000000008ab4 hardware_interrupt_common+0x114/0x120
--- Exception: 501 (Hardware Interrupt) at c000000000053040 livepatch_handler+0x4c/0x74
[c0000000eb9d4120] 0000000057ac6e9d (unreliable)
[d0000000089d9f78] 2e0965747962382e
SP (965747962342e09) is in userspace
When an interrupt occurs during the livepatch_handler execution, it's
possible for the livepatch_stack and/or thread_info to be corrupted.
eg:
Task A Interrupt Handler
========= =================
livepatch_handler:
mr r0, r1
ld r1, TI_livepatch_sp(r12)
hardware_interrupt_common:
do_IRQ+0x8:
mflr r0 <- saved stack pointer is overwritten
bl _mcount
...
std r27,-40(r1) <- overwrite of thread_info()
lis r2, STACK_END_MAGIC@h
ori r2, r2, STACK_END_MAGIC@l
ld r12, -8(r1)
Fix the corruption by using r11 register for livepatch stack
manipulation, instead of shuffling task stack and livepatch stack into
r1 register. Using r11 register also avoids disabling/enabling irq's
while setting up the livepatch stack.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:19:51 +03:00
|
|
|
subi r11, r11, 24
|
|
|
|
|
std r11, TI_livepatch_sp(r12)
|
2017-04-25 16:55:54 +03:00
|
|
|
|
|
|
|
|
/* Return to original caller of live patched function */
|
|
|
|
|
blr
|
|
|
|
|
#endif /* CONFIG_LIVEPATCH */
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
|
_GLOBAL(ftrace_graph_caller)
|
|
|
|
|
stdu r1, -112(r1)
|
|
|
|
|
/* with -mprofile-kernel, parameter regs are still alive at _mcount */
|
|
|
|
|
std r10, 104(r1)
|
|
|
|
|
std r9, 96(r1)
|
|
|
|
|
std r8, 88(r1)
|
|
|
|
|
std r7, 80(r1)
|
|
|
|
|
std r6, 72(r1)
|
|
|
|
|
std r5, 64(r1)
|
|
|
|
|
std r4, 56(r1)
|
|
|
|
|
std r3, 48(r1)
|
|
|
|
|
|
|
|
|
|
/* Save callee's TOC in the ABI compliant location */
|
|
|
|
|
std r2, 24(r1)
|
|
|
|
|
ld r2, PACATOC(r13) /* get kernel TOC in r2 */
|
|
|
|
|
|
2019-09-05 21:20:29 +03:00
|
|
|
addi r5, r1, 112
|
2017-04-25 16:55:54 +03:00
|
|
|
mfctr r4 /* ftrace_caller has moved local addr here */
|
|
|
|
|
std r4, 40(r1)
|
|
|
|
|
mflr r3 /* ftrace_caller has restored LR from stack */
|
|
|
|
|
subi r4, r4, MCOUNT_INSN_SIZE
|
|
|
|
|
|
|
|
|
|
bl prepare_ftrace_return
|
|
|
|
|
nop
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* prepare_ftrace_return gives us the address we divert to.
|
|
|
|
|
* Change the LR to this.
|
|
|
|
|
*/
|
|
|
|
|
mtlr r3
|
|
|
|
|
|
|
|
|
|
ld r0, 40(r1)
|
|
|
|
|
mtctr r0
|
|
|
|
|
ld r10, 104(r1)
|
|
|
|
|
ld r9, 96(r1)
|
|
|
|
|
ld r8, 88(r1)
|
|
|
|
|
ld r7, 80(r1)
|
|
|
|
|
ld r6, 72(r1)
|
|
|
|
|
ld r5, 64(r1)
|
|
|
|
|
ld r4, 56(r1)
|
|
|
|
|
ld r3, 48(r1)
|
|
|
|
|
|
|
|
|
|
/* Restore callee's TOC */
|
|
|
|
|
ld r2, 24(r1)
|
|
|
|
|
|
|
|
|
|
addi r1, r1, 112
|
|
|
|
|
mflr r0
|
|
|
|
|
std r0, LRSAVE(r1)
|
|
|
|
|
bctr
|
|
|
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
