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author | 2015-01-15 00:53:17 -0500 | |
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committer | 2015-01-15 00:53:17 -0500 | |
commit | 3f3558bb512e0762d5a4573a4aaf038d7a616e92 (patch) | |
tree | 1e2b43d410093e949209ca33614f5cdfdd16e80e /arch/x86/kernel/perf_regs.c | |
parent | ipv6:icmp:remove unnecessary brackets (diff) | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff) | |
download | linux-3f3558bb512e0762d5a4573a4aaf038d7a616e92.tar.gz linux-3f3558bb512e0762d5a4573a4aaf038d7a616e92.tar.bz2 linux-3f3558bb512e0762d5a4573a4aaf038d7a616e92.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
drivers/net/xen-netfront.c
Minor overlapping changes in xen-netfront.c, mostly to do
with some buffer management changes alongside the split
of stats into TX and RX.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/kernel/perf_regs.c')
-rw-r--r-- | arch/x86/kernel/perf_regs.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c index e309cc5c276e..781861cc5ee8 100644 --- a/arch/x86/kernel/perf_regs.c +++ b/arch/x86/kernel/perf_regs.c @@ -78,6 +78,14 @@ u64 perf_reg_abi(struct task_struct *task) { return PERF_SAMPLE_REGS_ABI_32; } + +void perf_get_regs_user(struct perf_regs *regs_user, + struct pt_regs *regs, + struct pt_regs *regs_user_copy) +{ + regs_user->regs = task_pt_regs(current); + regs_user->abi = perf_reg_abi(current); +} #else /* CONFIG_X86_64 */ #define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \ (1ULL << PERF_REG_X86_ES) | \ @@ -102,4 +110,86 @@ u64 perf_reg_abi(struct task_struct *task) else return PERF_SAMPLE_REGS_ABI_64; } + +void perf_get_regs_user(struct perf_regs *regs_user, + struct pt_regs *regs, + struct pt_regs *regs_user_copy) +{ + struct pt_regs *user_regs = task_pt_regs(current); + + /* + * If we're in an NMI that interrupted task_pt_regs setup, then + * we can't sample user regs at all. This check isn't really + * sufficient, though, as we could be in an NMI inside an interrupt + * that happened during task_pt_regs setup. + */ + if (regs->sp > (unsigned long)&user_regs->r11 && + regs->sp <= (unsigned long)(user_regs + 1)) { + regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; + regs_user->regs = NULL; + return; + } + + /* + * RIP, flags, and the argument registers are usually saved. + * orig_ax is probably okay, too. + */ + regs_user_copy->ip = user_regs->ip; + regs_user_copy->cx = user_regs->cx; + regs_user_copy->dx = user_regs->dx; + regs_user_copy->si = user_regs->si; + regs_user_copy->di = user_regs->di; + regs_user_copy->r8 = user_regs->r8; + regs_user_copy->r9 = user_regs->r9; + regs_user_copy->r10 = user_regs->r10; + regs_user_copy->r11 = user_regs->r11; + regs_user_copy->orig_ax = user_regs->orig_ax; + regs_user_copy->flags = user_regs->flags; + + /* + * Don't even try to report the "rest" regs. + */ + regs_user_copy->bx = -1; + regs_user_copy->bp = -1; + regs_user_copy->r12 = -1; + regs_user_copy->r13 = -1; + regs_user_copy->r14 = -1; + regs_user_copy->r15 = -1; + + /* + * For this to be at all useful, we need a reasonable guess for + * sp and the ABI. Be careful: we're in NMI context, and we're + * considering current to be the current task, so we should + * be careful not to look at any other percpu variables that might + * change during context switches. + */ + if (IS_ENABLED(CONFIG_IA32_EMULATION) && + task_thread_info(current)->status & TS_COMPAT) { + /* Easy case: we're in a compat syscall. */ + regs_user->abi = PERF_SAMPLE_REGS_ABI_32; + regs_user_copy->sp = user_regs->sp; + regs_user_copy->cs = user_regs->cs; + regs_user_copy->ss = user_regs->ss; + } else if (user_regs->orig_ax != -1) { + /* + * We're probably in a 64-bit syscall. + * Warning: this code is severely racy. At least it's better + * than just blindly copying user_regs. + */ + regs_user->abi = PERF_SAMPLE_REGS_ABI_64; + regs_user_copy->sp = this_cpu_read(old_rsp); + regs_user_copy->cs = __USER_CS; + regs_user_copy->ss = __USER_DS; + regs_user_copy->cx = -1; /* usually contains garbage */ + } else { + /* We're probably in an interrupt or exception. */ + regs_user->abi = user_64bit_mode(user_regs) ? + PERF_SAMPLE_REGS_ABI_64 : PERF_SAMPLE_REGS_ABI_32; + regs_user_copy->sp = user_regs->sp; + regs_user_copy->cs = user_regs->cs; + regs_user_copy->ss = user_regs->ss; + } + + regs_user->regs = regs_user_copy; +} #endif /* CONFIG_X86_32 */ |