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authorTakashi Iwai <tiwai@suse.de>2017-07-03 20:51:42 +0300
committerTakashi Iwai <tiwai@suse.de>2017-07-03 20:51:42 +0300
commit818a23e3882b1bf65d1719e407be04716e69a4d5 (patch)
tree6e4267b570541f779e7d85c11eb14312fa86fbb1 /arch/x86/kernel/unwind_frame.c
parenta178232ddab55048e347b43b697bfa5013ef819e (diff)
parentb821d298f8864dc3c3d42643812df43289159507 (diff)
downloadlinux-818a23e3882b1bf65d1719e407be04716e69a4d5.tar.xz
Merge tag 'asoc-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v4.13 The big news with this release is the of-graph card, this provides a replacement for simple-card that is much more flexibile and scalable, allowing many more systems to use a generic sound card than was possible before: - The of-graph card, finally merged after a long and dedicated effort by Morimoto-san. - New widget types intended mainly for use with DSPs. - New drivers for Allwinner V3s SoCs, Ensonic ES8316, several classes of x86 machine, Rockchip PDM controllers, STM32 I2S and S/PDIF controllers and ZTE AUD96P22 CODECs.
Diffstat (limited to 'arch/x86/kernel/unwind_frame.c')
-rw-r--r--arch/x86/kernel/unwind_frame.c49
1 files changed, 40 insertions, 9 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index 82c6d7f1fd73..b9389d72b2f7 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c
@@ -104,6 +104,11 @@ static inline unsigned long *last_frame(struct unwind_state *state)
return (unsigned long *)task_pt_regs(state->task) - 2;
}
+static bool is_last_frame(struct unwind_state *state)
+{
+ return state->bp == last_frame(state);
+}
+
#ifdef CONFIG_X86_32
#define GCC_REALIGN_WORDS 3
#else
@@ -115,16 +120,15 @@ static inline unsigned long *last_aligned_frame(struct unwind_state *state)
return last_frame(state) - GCC_REALIGN_WORDS;
}
-static bool is_last_task_frame(struct unwind_state *state)
+static bool is_last_aligned_frame(struct unwind_state *state)
{
unsigned long *last_bp = last_frame(state);
unsigned long *aligned_bp = last_aligned_frame(state);
/*
- * We have to check for the last task frame at two different locations
- * because gcc can occasionally decide to realign the stack pointer and
- * change the offset of the stack frame in the prologue of a function
- * called by head/entry code. Examples:
+ * GCC can occasionally decide to realign the stack pointer and change
+ * the offset of the stack frame in the prologue of a function called
+ * by head/entry code. Examples:
*
* <start_secondary>:
* push %edi
@@ -141,11 +145,38 @@ static bool is_last_task_frame(struct unwind_state *state)
* push %rbp
* mov %rsp,%rbp
*
- * Note that after aligning the stack, it pushes a duplicate copy of
- * the return address before pushing the frame pointer.
+ * After aligning the stack, it pushes a duplicate copy of the return
+ * address before pushing the frame pointer.
+ */
+ return (state->bp == aligned_bp && *(aligned_bp + 1) == *(last_bp + 1));
+}
+
+static bool is_last_ftrace_frame(struct unwind_state *state)
+{
+ unsigned long *last_bp = last_frame(state);
+ unsigned long *last_ftrace_bp = last_bp - 3;
+
+ /*
+ * When unwinding from an ftrace handler of a function called by entry
+ * code, the stack layout of the last frame is:
+ *
+ * bp
+ * parent ret addr
+ * bp
+ * function ret addr
+ * parent ret addr
+ * pt_regs
+ * -----------------
*/
- return (state->bp == last_bp ||
- (state->bp == aligned_bp && *(aligned_bp+1) == *(last_bp+1)));
+ return (state->bp == last_ftrace_bp &&
+ *state->bp == *(state->bp + 2) &&
+ *(state->bp + 1) == *(state->bp + 4));
+}
+
+static bool is_last_task_frame(struct unwind_state *state)
+{
+ return is_last_frame(state) || is_last_aligned_frame(state) ||
+ is_last_ftrace_frame(state);
}
/*