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authorRichard Henderson <rth@twiddle.net>2017-07-18 10:02:33 -1000
committerAurelien Jarno <aurelien@aurel32.net>2017-07-18 23:39:16 +0200
commitb0e4f0edf575f72d8d76717ecbefa9c748ab467b (patch)
tree1f77bfb4b132ee85a7e875da73c27174713cbbb4 /linux-user
parentd6a6cffdd3d861c2cdd09253369bba50f9e3d891 (diff)
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linux-user/sh4: Notice gUSA regions during signal delivery
We translate gUSA regions atomically in a parallel context. But in a serial context a gUSA region may be interrupted. In that case, restart the region as the kernel would. Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Richard Henderson <rth@twiddle.net> Message-Id: <20170718200255.31647-9-rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/signal.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 3d18d1b..c8b0733 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -3471,6 +3471,30 @@ static abi_ulong get_sigframe(struct target_sigaction *ka,
return (sp - frame_size) & -8ul;
}
+/* Notice when we're in the middle of a gUSA region and reset.
+ Note that this will only occur for !parallel_cpus, as we will
+ translate such sequences differently in a parallel context. */
+static void unwind_gusa(CPUSH4State *regs)
+{
+ /* If the stack pointer is sufficiently negative, and we haven't
+ completed the sequence, then reset to the entry to the region. */
+ /* ??? The SH4 kernel checks for and address above 0xC0000000.
+ However, the page mappings in qemu linux-user aren't as restricted
+ and we wind up with the normal stack mapped above 0xF0000000.
+ That said, there is no reason why the kernel should be allowing
+ a gUSA region that spans 1GB. Use a tighter check here, for what
+ can actually be enabled by the immediate move. */
+ if (regs->gregs[15] >= -128u && regs->pc < regs->gregs[0]) {
+ /* Reset the PC to before the gUSA region, as computed from
+ R0 = region end, SP = -(region size), plus one more for the
+ insn that actually initializes SP to the region size. */
+ regs->pc = regs->gregs[0] + regs->gregs[15] - 2;
+
+ /* Reset the SP to the saved version in R1. */
+ regs->gregs[15] = regs->gregs[1];
+ }
+}
+
static void setup_sigcontext(struct target_sigcontext *sc,
CPUSH4State *regs, unsigned long mask)
{
@@ -3534,6 +3558,8 @@ static void setup_frame(int sig, struct target_sigaction *ka,
abi_ulong frame_addr;
int i;
+ unwind_gusa(regs);
+
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
@@ -3583,6 +3609,8 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka,
abi_ulong frame_addr;
int i;
+ unwind_gusa(regs);
+
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_rt_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {