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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-02 12:54:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-02 12:54:34 -0700
commit019b3fd94ba73d3ac615f0537440b81f129821f6 (patch)
tree09657e8fd2ff04295381e9c6492553fe16c58ab4 /arch/powerpc/kernel/kprobes.c
parent4cad67197989c81417810b89f09a3549b75a2441 (diff)
parent4ebbbaa4ce8524b853dd6febf0176a6efa3482d7 (diff)
Merge tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman: - A big series refactoring parts of our KVM code, and converting some to C. - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on some CPUs. - Support for the Microwatt soft-core. - Optimisations to our interrupt return path on 64-bit. - Support for userspace access to the NX GZIP accelerator on PowerVM on Power10. - Enable KUAP and KUEP by default on 32-bit Book3S CPUs. - Other smaller features, fixes & cleanups. Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand, Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe, Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei. * tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits) powerpc: Only build restart_table.c for 64s powerpc/64s: move ret_from_fork etc above __end_soft_masked powerpc/64s/interrupt: clean up interrupt return labels powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols powerpc/64: enable MSR[EE] in irq replay pt_regs powerpc/64s/interrupt: preserve regs->softe for NMI interrupts powerpc/64s: add a table of implicit soft-masked addresses powerpc/64e: remove implicit soft-masking and interrupt exit restart logic powerpc/64e: fix CONFIG_RELOCATABLE build warnings powerpc/64s: fix hash page fault interrupt handler powerpc/4xx: Fix setup_kuep() on SMP powerpc/32s: Fix setup_{kuap/kuep}() on SMP powerpc/interrupt: Use names in check_return_regs_valid() powerpc/interrupt: Also use exit_must_hard_disable() on PPC32 powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE powerpc/ptrace: Refactor regs_set_return_{msr/ip} powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip} powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() powerpc/pseries/vas: Include irqdomain.h powerpc: mark local variables around longjmp as volatile ...
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
-rw-r--r--arch/powerpc/kernel/kprobes.c61
1 files changed, 40 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index c64a5feaebbe..cbc28d1a2e1b 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -19,11 +19,13 @@
#include <linux/extable.h>
#include <linux/kdebug.h>
#include <linux/slab.h>
+#include <linux/moduleloader.h>
#include <asm/code-patching.h>
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/sections.h>
#include <asm/inst.h>
+#include <asm/set_memory.h>
#include <linux/uaccess.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -103,28 +105,42 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
return addr;
}
+void *alloc_insn_page(void)
+{
+ void *page;
+
+ page = module_alloc(PAGE_SIZE);
+ if (!page)
+ return NULL;
+
+ if (strict_module_rwx_enabled()) {
+ set_memory_ro((unsigned long)page, 1);
+ set_memory_x((unsigned long)page, 1);
+ }
+ return page;
+}
+
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
struct kprobe *prev;
- struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr);
+ struct ppc_inst insn = ppc_inst_read(p->addr);
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
ret = -EINVAL;
- } else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) {
- printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n");
+ } else if (IS_MTMSRD(insn) || IS_RFID(insn)) {
+ printk("Cannot register a kprobe on mtmsr[d]/rfi[d]\n");
ret = -EINVAL;
} else if ((unsigned long)p->addr & ~PAGE_MASK &&
- ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)(p->addr - 1)))) {
+ ppc_inst_prefixed(ppc_inst_read(p->addr - 1))) {
printk("Cannot register a kprobe on the second word of prefixed instruction\n");
ret = -EINVAL;
}
preempt_disable();
prev = get_kprobe(p->addr - 1);
preempt_enable_no_resched();
- if (prev &&
- ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) {
+ if (prev && ppc_inst_prefixed(ppc_inst_read(prev->ainsn.insn))) {
printk("Cannot register a kprobe on the second word of prefixed instruction\n");
ret = -EINVAL;
}
@@ -138,7 +154,7 @@ int arch_prepare_kprobe(struct kprobe *p)
}
if (!ret) {
- patch_instruction((struct ppc_inst *)p->ainsn.insn, insn);
+ patch_instruction(p->ainsn.insn, insn);
p->opcode = ppc_inst_val(insn);
}
@@ -149,13 +165,13 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe);
void arch_arm_kprobe(struct kprobe *p)
{
- patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION));
+ WARN_ON_ONCE(patch_instruction(p->addr, ppc_inst(BREAKPOINT_INSTRUCTION)));
}
NOKPROBE_SYMBOL(arch_arm_kprobe);
void arch_disarm_kprobe(struct kprobe *p)
{
- patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode));
+ WARN_ON_ONCE(patch_instruction(p->addr, ppc_inst(p->opcode)));
}
NOKPROBE_SYMBOL(arch_disarm_kprobe);
@@ -178,7 +194,7 @@ static nokprobe_inline void prepare_singlestep(struct kprobe *p, struct pt_regs
* variant as values in regs could play a part in
* if the trap is taken or not
*/
- regs->nip = (unsigned long)p->ainsn.insn;
+ regs_set_return_ip(regs, (unsigned long)p->ainsn.insn);
}
static nokprobe_inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -228,7 +244,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
{
int ret;
- struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
+ struct ppc_inst insn = ppc_inst_read(p->ainsn.insn);
/* regs->nip is also adjusted if emulate_step returns 1 */
ret = emulate_step(regs, insn);
@@ -319,8 +335,9 @@ int kprobe_handler(struct pt_regs *regs)
kprobe_opcode_t insn = *p->ainsn.insn;
if (kcb->kprobe_status == KPROBE_HIT_SS && is_trap(insn)) {
/* Turn off 'trace' bits */
- regs->msr &= ~MSR_SINGLESTEP;
- regs->msr |= kcb->kprobe_saved_msr;
+ regs_set_return_msr(regs,
+ (regs->msr & ~MSR_SINGLESTEP) |
+ kcb->kprobe_saved_msr);
goto no_kprobe;
}
@@ -415,7 +432,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* we end up emulating it in kprobe_handler(), which increments the nip
* again.
*/
- regs->nip = orig_ret_address - 4;
+ regs_set_return_ip(regs, orig_ret_address - 4);
regs->link = orig_ret_address;
return 0;
@@ -439,7 +456,7 @@ int kprobe_post_handler(struct pt_regs *regs)
if (!cur || user_mode(regs))
return 0;
- len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn));
+ len = ppc_inst_len(ppc_inst_read(cur->ainsn.insn));
/* make sure we got here for instruction we have a kprobe on */
if (((unsigned long)cur->ainsn.insn + len) != regs->nip)
return 0;
@@ -450,8 +467,8 @@ int kprobe_post_handler(struct pt_regs *regs)
}
/* Adjust nip to after the single-stepped instruction */
- regs->nip = (unsigned long)cur->addr + len;
- regs->msr |= kcb->kprobe_saved_msr;
+ regs_set_return_ip(regs, (unsigned long)cur->addr + len);
+ regs_set_return_msr(regs, regs->msr | kcb->kprobe_saved_msr);
/*Restore back the original saved kprobes variables and continue. */
if (kcb->kprobe_status == KPROBE_REENTER) {
@@ -490,9 +507,11 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* and allow the page fault handler to continue as a
* normal page fault.
*/
- regs->nip = (unsigned long)cur->addr;
- regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
- regs->msr |= kcb->kprobe_saved_msr;
+ regs_set_return_ip(regs, (unsigned long)cur->addr);
+ /* Turn off 'trace' bits */
+ regs_set_return_msr(regs,
+ (regs->msr & ~MSR_SINGLESTEP) |
+ kcb->kprobe_saved_msr);
if (kcb->kprobe_status == KPROBE_REENTER)
restore_previous_kprobe(kcb);
else
@@ -506,7 +525,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* zero, try to fix up.
*/
if ((entry = search_exception_tables(regs->nip)) != NULL) {
- regs->nip = extable_fixup(entry);
+ regs_set_return_ip(regs, extable_fixup(entry));
return 1;
}