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authorAlex Bennée <alex.bennee@linaro.org>2019-05-30 15:35:14 +0100
committerAlex Bennée <alex.bennee@linaro.org>2019-06-12 17:53:22 +0100
commit78e24848f6a2923f356d15d8751c644f94a39fd8 (patch)
treef9a6d5636870a08f820e9186ade7738dd656487f
parent3ace9be6d267b2f876ebb34096fe5d9b64a82d9a (diff)
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semihosting: split console_out into string and char versions
This is ostensibly to avoid the weirdness of len looking like it might come from a guest and sometimes being used. While we are at it fix up the error checking for the arm-linux-user implementation of the API which got flagged up by Coverity (CID 1401700). Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
-rw-r--r--hw/semihosting/console.c34
-rw-r--r--include/hw/semihosting/console.h25
-rw-r--r--linux-user/arm/semihost.c31
-rw-r--r--target/arm/arm-semi.c4
4 files changed, 74 insertions, 20 deletions
diff --git a/hw/semihosting/console.c b/hw/semihosting/console.c
index 4ab7533..b4b17c8 100644
--- a/hw/semihosting/console.c
+++ b/hw/semihosting/console.c
@@ -36,26 +36,24 @@ int qemu_semihosting_log_out(const char *s, int len)
/*
* A re-implementation of lock_user_string that we can use locally
* instead of relying on softmmu-semi. Hopefully we can deprecate that
- * in time. We either copy len bytes if specified or until we find a NULL.
+ * in time. Copy string until we find a 0 or address error.
*/
-static GString *copy_user_string(CPUArchState *env, target_ulong addr, int len)
+static GString *copy_user_string(CPUArchState *env, target_ulong addr)
{
CPUState *cpu = env_cpu(env);
- GString *s = g_string_sized_new(len ? len : 128);
+ GString *s = g_string_sized_new(128);
uint8_t c;
- bool done;
do {
if (cpu_memory_rw_debug(cpu, addr++, &c, 1, 0) == 0) {
s = g_string_append_c(s, c);
- done = len ? s->len == len : c == 0;
} else {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: passed inaccessible address " TARGET_FMT_lx,
__func__, addr);
- done = true;
+ break;
}
- } while (!done);
+ } while (c!=0);
return s;
}
@@ -68,9 +66,9 @@ static void semihosting_cb(CPUState *cs, target_ulong ret, target_ulong err)
}
}
-int qemu_semihosting_console_out(CPUArchState *env, target_ulong addr, int len)
+int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr)
{
- GString *s = copy_user_string(env, addr, len);
+ GString *s = copy_user_string(env, addr);
int out = s->len;
if (use_gdb_syscalls()) {
@@ -82,3 +80,21 @@ int qemu_semihosting_console_out(CPUArchState *env, target_ulong addr, int len)
g_string_free(s, true);
return out;
}
+
+void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr)
+{
+ CPUState *cpu = env_cpu(env);
+ uint8_t c;
+
+ if (cpu_memory_rw_debug(cpu, addr, &c, 1, 0) == 0) {
+ if (use_gdb_syscalls()) {
+ gdb_do_syscall(semihosting_cb, "write,2,%x,%x", addr, 1);
+ } else {
+ qemu_semihosting_log_out((const char *) &c, 1);
+ }
+ } else {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: passed inaccessible address " TARGET_FMT_lx,
+ __func__, addr);
+ }
+}
diff --git a/include/hw/semihosting/console.h b/include/hw/semihosting/console.h
index 9eb45b7..cfab572 100644
--- a/include/hw/semihosting/console.h
+++ b/include/hw/semihosting/console.h
@@ -10,17 +10,30 @@
#define SEMIHOST_CONSOLE_H
/**
- * qemu_semihosting_console_out:
+ * qemu_semihosting_console_outs:
* @env: CPUArchState
- * @s: host address of guest string
- * @len: length of string or 0 (string is null terminated)
+ * @s: host address of null terminated guest string
*
- * Send a guest string to the debug console. This may be the remote
- * gdb session if a softmmu guest is currently being debugged.
+ * Send a null terminated guest string to the debug console. This may
+ * be the remote gdb session if a softmmu guest is currently being
+ * debugged.
*
* Returns: number of bytes written.
*/
-int qemu_semihosting_console_out(CPUArchState *env, target_ulong s, int len);
+int qemu_semihosting_console_outs(CPUArchState *env, target_ulong s);
+
+/**
+ * qemu_semihosting_console_outc:
+ * @env: CPUArchState
+ * @s: host address of null terminated guest string
+ *
+ * Send single character from guest memory to the debug console. This
+ * may be the remote gdb session if a softmmu guest is currently being
+ * debugged.
+ *
+ * Returns: nothing
+ */
+void qemu_semihosting_console_outc(CPUArchState *env, target_ulong c);
/**
* qemu_semihosting_log_out:
diff --git a/linux-user/arm/semihost.c b/linux-user/arm/semihost.c
index 9554102..a16b525 100644
--- a/linux-user/arm/semihost.c
+++ b/linux-user/arm/semihost.c
@@ -15,10 +15,35 @@
#include "hw/semihosting/console.h"
#include "qemu.h"
-int qemu_semihosting_console_out(CPUArchState *env, target_ulong addr, int len)
+int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr)
{
- void *s = lock_user_string(addr);
- len = write(STDERR_FILENO, s, len ? len : strlen(s));
+ int len = target_strlen(addr);
+ void *s;
+ if (len < 0){
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: passed inaccessible address " TARGET_FMT_lx,
+ __func__, addr);
+ return 0;
+ }
+ s = lock_user(VERIFY_READ, addr, (long)(len + 1), 1);
+ g_assert(s); /* target_strlen has already verified this will work */
+ len = write(STDERR_FILENO, s, len);
unlock_user(s, addr, 0);
return len;
}
+
+void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr)
+{
+ char c;
+
+ if (get_user_u8(c, addr)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: passed inaccessible address " TARGET_FMT_lx,
+ __func__, addr);
+ } else {
+ if (write(STDERR_FILENO, &c, 1) != 1) {
+ qemu_log_mask(LOG_UNIMP, "%s: unexpected write to stdout failure",
+ __func__);
+ }
+ }
+}
diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
index bca9a25..90423a3 100644
--- a/target/arm/arm-semi.c
+++ b/target/arm/arm-semi.c
@@ -314,10 +314,10 @@ target_ulong do_arm_semihosting(CPUARMState *env)
return set_swi_errno(ts, close(arg0));
}
case TARGET_SYS_WRITEC:
- qemu_semihosting_console_out(env, args, 1);
+ qemu_semihosting_console_outc(env, args);
return 0xdeadbeef;
case TARGET_SYS_WRITE0:
- return qemu_semihosting_console_out(env, args, 0);
+ return qemu_semihosting_console_outs(env, args);
case TARGET_SYS_WRITE:
GET_ARG(0);
GET_ARG(1);