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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-05 13:20:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-05 13:20:43 -0700
commit2d1eb87ae1e6f3999e77989fd2f831b134270787 (patch)
treeadf505adb17c96929c797920613afa3dc5731650 /arch/arm/kernel/uprobes-arm.c
parent2f997759dffe5458446075a58734df39d8035e6e (diff)
parentbce5669be3a8946952258a064ef26defeb887138 (diff)
downloadblackbird-op-linux-2d1eb87ae1e6f3999e77989fd2f831b134270787.tar.gz
blackbird-op-linux-2d1eb87ae1e6f3999e77989fd2f831b134270787.zip
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM changes from Russell King: - Perf updates from Will Deacon: - Support for Qualcomm Krait processors (run perf on your phone!) - Support for Cortex-A12 (run perf stat on your FPGA!) - Support for perf_sample_event_took, allowing us to automatically decrease the sample rate if we can't handle the PMU interrupts quickly enough (run perf record on your FPGA!). - Basic uprobes support from David Long: This patch series adds basic uprobes support to ARM. It is based on patches developed earlier by Rabin Vincent. That approach of adding hooks into the kprobes instruction parsing code was not well received. This approach separates the ARM instruction parsing code in kprobes out into a separate set of functions which can be used by both kprobes and uprobes. Both kprobes and uprobes then provide their own semantic action tables to process the results of the parsing. - ARMv7M (microcontroller) updates from Uwe Kleine-König - OMAP DMA updates (recently added Vinod's Ack even though they've been sitting in linux-next for a few months) to reduce the reliance of omap-dma on the code in arch/arm. - SA11x0 changes from Dmitry Eremin-Solenikov and Alexander Shiyan - Support for Cortex-A12 CPU - Align support for ARMv6 with ARMv7 so they can cooperate better in a single zImage. - Addition of first AT_HWCAP2 feature bits for ARMv8 crypto support. - Removal of IRQ_DISABLED from various ARM files - Improved efficiency of virt_to_page() for single zImage - Patch from Ulf Hansson to permit runtime PM callbacks to be available for AMBA devices for suspend/resume as well. - Finally kill asm/system.h on ARM. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (89 commits) dmaengine: omap-dma: more consolidation of CCR register setup dmaengine: omap-dma: move IRQ handling to omap-dma dmaengine: omap-dma: move register read/writes into omap-dma.c ARM: omap: dma: get rid of 'p' allocation and clean up ARM: omap: move dma channel allocation into plat-omap code ARM: omap: dma: get rid of errata global ARM: omap: clean up DMA register accesses ARM: omap: remove almost-const variables ARM: omap: remove references to disable_irq_lch dmaengine: omap-dma: cleanup errata 3.3 handling dmaengine: omap-dma: provide register read/write functions dmaengine: omap-dma: use cached CCR value when enabling DMA dmaengine: omap-dma: move barrier to omap_dma_start_desc() dmaengine: omap-dma: move clnk_ctrl setting to preparation functions dmaengine: omap-dma: improve efficiency loading C.SA/C.EI/C.FI registers dmaengine: omap-dma: consolidate clearing channel status register dmaengine: omap-dma: move CCR buffering disable errata out of the fast path dmaengine: omap-dma: provide register definitions dmaengine: omap-dma: consolidate setup of CCR dmaengine: omap-dma: consolidate setup of CSDP ...
Diffstat (limited to 'arch/arm/kernel/uprobes-arm.c')
-rw-r--r--arch/arm/kernel/uprobes-arm.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/arch/arm/kernel/uprobes-arm.c b/arch/arm/kernel/uprobes-arm.c
new file mode 100644
index 000000000000..d3b655ff17da
--- /dev/null
+++ b/arch/arm/kernel/uprobes-arm.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2012 Rabin Vincent <rabin at rab.in>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/wait.h>
+#include <linux/uprobes.h>
+#include <linux/module.h>
+
+#include "probes.h"
+#include "probes-arm.h"
+#include "uprobes.h"
+
+static int uprobes_substitute_pc(unsigned long *pinsn, u32 oregs)
+{
+ probes_opcode_t insn = __mem_to_opcode_arm(*pinsn);
+ probes_opcode_t temp;
+ probes_opcode_t mask;
+ int freereg;
+ u32 free = 0xffff;
+ u32 regs;
+
+ for (regs = oregs; regs; regs >>= 4, insn >>= 4) {
+ if ((regs & 0xf) == REG_TYPE_NONE)
+ continue;
+
+ free &= ~(1 << (insn & 0xf));
+ }
+
+ /* No PC, no problem */
+ if (free & (1 << 15))
+ return 15;
+
+ if (!free)
+ return -1;
+
+ /*
+ * fls instead of ffs ensures that for "ldrd r0, r1, [pc]" we would
+ * pick LR instead of R1.
+ */
+ freereg = free = fls(free) - 1;
+
+ temp = __mem_to_opcode_arm(*pinsn);
+ insn = temp;
+ regs = oregs;
+ mask = 0xf;
+
+ for (; regs; regs >>= 4, mask <<= 4, free <<= 4, temp >>= 4) {
+ if ((regs & 0xf) == REG_TYPE_NONE)
+ continue;
+
+ if ((temp & 0xf) != 15)
+ continue;
+
+ insn &= ~mask;
+ insn |= free & mask;
+ }
+
+ *pinsn = __opcode_to_mem_arm(insn);
+ return freereg;
+}
+
+static void uprobe_set_pc(struct arch_uprobe *auprobe,
+ struct arch_uprobe_task *autask,
+ struct pt_regs *regs)
+{
+ u32 pcreg = auprobe->pcreg;
+
+ autask->backup = regs->uregs[pcreg];
+ regs->uregs[pcreg] = regs->ARM_pc + 8;
+}
+
+static void uprobe_unset_pc(struct arch_uprobe *auprobe,
+ struct arch_uprobe_task *autask,
+ struct pt_regs *regs)
+{
+ /* PC will be taken care of by common code */
+ regs->uregs[auprobe->pcreg] = autask->backup;
+}
+
+static void uprobe_aluwrite_pc(struct arch_uprobe *auprobe,
+ struct arch_uprobe_task *autask,
+ struct pt_regs *regs)
+{
+ u32 pcreg = auprobe->pcreg;
+
+ alu_write_pc(regs->uregs[pcreg], regs);
+ regs->uregs[pcreg] = autask->backup;
+}
+
+static void uprobe_write_pc(struct arch_uprobe *auprobe,
+ struct arch_uprobe_task *autask,
+ struct pt_regs *regs)
+{
+ u32 pcreg = auprobe->pcreg;
+
+ load_write_pc(regs->uregs[pcreg], regs);
+ regs->uregs[pcreg] = autask->backup;
+}
+
+enum probes_insn
+decode_pc_ro(probes_opcode_t insn, struct arch_probes_insn *asi,
+ const struct decode_header *d)
+{
+ struct arch_uprobe *auprobe = container_of(asi, struct arch_uprobe,
+ asi);
+ struct decode_emulate *decode = (struct decode_emulate *) d;
+ u32 regs = decode->header.type_regs.bits >> DECODE_TYPE_BITS;
+ int reg;
+
+ reg = uprobes_substitute_pc(&auprobe->ixol[0], regs);
+ if (reg == 15)
+ return INSN_GOOD;
+
+ if (reg == -1)
+ return INSN_REJECTED;
+
+ auprobe->pcreg = reg;
+ auprobe->prehandler = uprobe_set_pc;
+ auprobe->posthandler = uprobe_unset_pc;
+
+ return INSN_GOOD;
+}
+
+enum probes_insn
+decode_wb_pc(probes_opcode_t insn, struct arch_probes_insn *asi,
+ const struct decode_header *d, bool alu)
+{
+ struct arch_uprobe *auprobe = container_of(asi, struct arch_uprobe,
+ asi);
+ enum probes_insn ret = decode_pc_ro(insn, asi, d);
+
+ if (((insn >> 12) & 0xf) == 15)
+ auprobe->posthandler = alu ? uprobe_aluwrite_pc
+ : uprobe_write_pc;
+
+ return ret;
+}
+
+enum probes_insn
+decode_rd12rn16rm0rs8_rwflags(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *d)
+{
+ return decode_wb_pc(insn, asi, d, true);
+}
+
+enum probes_insn
+decode_ldr(probes_opcode_t insn, struct arch_probes_insn *asi,
+ const struct decode_header *d)
+{
+ return decode_wb_pc(insn, asi, d, false);
+}
+
+enum probes_insn
+uprobe_decode_ldmstm(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *d)
+{
+ struct arch_uprobe *auprobe = container_of(asi, struct arch_uprobe,
+ asi);
+ unsigned reglist = insn & 0xffff;
+ int rn = (insn >> 16) & 0xf;
+ int lbit = insn & (1 << 20);
+ unsigned used = reglist | (1 << rn);
+
+ if (rn == 15)
+ return INSN_REJECTED;
+
+ if (!(used & (1 << 15)))
+ return INSN_GOOD;
+
+ if (used & (1 << 14))
+ return INSN_REJECTED;
+
+ /* Use LR instead of PC */
+ insn ^= 0xc000;
+
+ auprobe->pcreg = 14;
+ auprobe->ixol[0] = __opcode_to_mem_arm(insn);
+
+ auprobe->prehandler = uprobe_set_pc;
+ if (lbit)
+ auprobe->posthandler = uprobe_write_pc;
+ else
+ auprobe->posthandler = uprobe_unset_pc;
+
+ return INSN_GOOD;
+}
+
+const union decode_action uprobes_probes_actions[] = {
+ [PROBES_EMULATE_NONE] = {.handler = probes_simulate_nop},
+ [PROBES_SIMULATE_NOP] = {.handler = probes_simulate_nop},
+ [PROBES_PRELOAD_IMM] = {.handler = probes_simulate_nop},
+ [PROBES_PRELOAD_REG] = {.handler = probes_simulate_nop},
+ [PROBES_BRANCH_IMM] = {.handler = simulate_blx1},
+ [PROBES_MRS] = {.handler = simulate_mrs},
+ [PROBES_BRANCH_REG] = {.handler = simulate_blx2bx},
+ [PROBES_CLZ] = {.handler = probes_simulate_nop},
+ [PROBES_SATURATING_ARITHMETIC] = {.handler = probes_simulate_nop},
+ [PROBES_MUL1] = {.handler = probes_simulate_nop},
+ [PROBES_MUL2] = {.handler = probes_simulate_nop},
+ [PROBES_SWP] = {.handler = probes_simulate_nop},
+ [PROBES_LDRSTRD] = {.decoder = decode_pc_ro},
+ [PROBES_LOAD_EXTRA] = {.decoder = decode_pc_ro},
+ [PROBES_LOAD] = {.decoder = decode_ldr},
+ [PROBES_STORE_EXTRA] = {.decoder = decode_pc_ro},
+ [PROBES_STORE] = {.decoder = decode_pc_ro},
+ [PROBES_MOV_IP_SP] = {.handler = simulate_mov_ipsp},
+ [PROBES_DATA_PROCESSING_REG] = {
+ .decoder = decode_rd12rn16rm0rs8_rwflags},
+ [PROBES_DATA_PROCESSING_IMM] = {
+ .decoder = decode_rd12rn16rm0rs8_rwflags},
+ [PROBES_MOV_HALFWORD] = {.handler = probes_simulate_nop},
+ [PROBES_SEV] = {.handler = probes_simulate_nop},
+ [PROBES_WFE] = {.handler = probes_simulate_nop},
+ [PROBES_SATURATE] = {.handler = probes_simulate_nop},
+ [PROBES_REV] = {.handler = probes_simulate_nop},
+ [PROBES_MMI] = {.handler = probes_simulate_nop},
+ [PROBES_PACK] = {.handler = probes_simulate_nop},
+ [PROBES_EXTEND] = {.handler = probes_simulate_nop},
+ [PROBES_EXTEND_ADD] = {.handler = probes_simulate_nop},
+ [PROBES_MUL_ADD_LONG] = {.handler = probes_simulate_nop},
+ [PROBES_MUL_ADD] = {.handler = probes_simulate_nop},
+ [PROBES_BITFIELD] = {.handler = probes_simulate_nop},
+ [PROBES_BRANCH] = {.handler = simulate_bbl},
+ [PROBES_LDMSTM] = {.decoder = uprobe_decode_ldmstm}
+};
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