diff options
| author | Arun Sharma <asharma@fb.com> | 2012-04-21 00:41:35 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-06-06 17:08:01 +0200 |
| commit | bc6ca7b342d5ae15c3ba3081fd40271b8039fb25 (patch) | |
| tree | c2fbb2f922b48a450df5b66c0dca13ba6fd51f98 | |
| parent | perf: Limit callchains to 127 (diff) | |
| download | linux-bc6ca7b342d5ae15c3ba3081fd40271b8039fb25.tar.xz linux-bc6ca7b342d5ae15c3ba3081fd40271b8039fb25.zip | |
perf/x86: Check if user fp is valid
Signed-off-by: Arun Sharma <asharma@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1334961696-19580-4-git-send-email-asharma@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 12 |
2 files changed, 18 insertions, 6 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 04cd6882308e..e1f3a17034fc 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -33,9 +33,8 @@ #define segment_eq(a, b) ((a).seg == (b).seg) #define user_addr_max() (current_thread_info()->addr_limit.seg) -#define __addr_ok(addr) \ - ((unsigned long __force)(addr) < \ - (current_thread_info()->addr_limit.seg)) +#define __addr_ok(addr) \ + ((unsigned long __force)(addr) < user_addr_max()) /* * Test whether a block of memory is a valid user space address. @@ -47,14 +46,14 @@ * This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry... */ -#define __range_not_ok(addr, size) \ +#define __range_not_ok(addr, size, limit) \ ({ \ unsigned long flag, roksum; \ __chk_user_ptr(addr); \ asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0" \ : "=&r" (flag), "=r" (roksum) \ : "1" (addr), "g" ((long)(size)), \ - "rm" (current_thread_info()->addr_limit.seg)); \ + "rm" (limit)); \ flag; \ }) @@ -77,7 +76,8 @@ * checks that the pointer is in the user space range - after calling * this function, memory access functions may still return -EFAULT. */ -#define access_ok(type, addr, size) (likely(__range_not_ok(addr, size) == 0)) +#define access_ok(type, addr, size) \ + (likely(__range_not_ok(addr, size, user_addr_max()) == 0)) /* * The exception table consists of pairs of addresses relative to the diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index e78bc256aea8..c4706cf9c011 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1757,6 +1757,12 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); } +static inline int +valid_user_frame(const void __user *fp, unsigned long size) +{ + return (__range_not_ok(fp, size, TASK_SIZE) == 0); +} + #ifdef CONFIG_COMPAT #include <asm/compat.h> @@ -1781,6 +1787,9 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) if (bytes != sizeof(frame)) break; + if (!valid_user_frame(fp, sizeof(frame))) + break; + perf_callchain_store(entry, frame.return_address); fp = compat_ptr(frame.next_frame); } @@ -1824,6 +1833,9 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) if (bytes != sizeof(frame)) break; + if (!valid_user_frame(fp, sizeof(frame))) + break; + perf_callchain_store(entry, frame.return_address); fp = frame.next_frame; } |