| Message ID | 20200330192157.1335-4-julien@xen.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix build with using OCaml 4.06.1 and -safe-string | expand |
Julien Grall writes ("[PATCH 3/8] tools/libxc: misc: Mark const the parameter 'keys' of xc_send_debug_keys()"):
> From: Julien Grall <jgrall@amazon.com>
>
> OCaml is using a string to describe the parameter 'keys' of
> xc_send_debug_keys(). Since Ocaml 4.06.01, String_val() will return a
> const char * when using -safe-string. This will result to a build
> failure because xc_send_debug_keys() expects a char *.
>
> The function should never modify the parameter 'keys' and therefore the
> parameter should be const. Unfortunately, this is not directly possible
> because DECLARE_HYPERCALL_BOUNCE() is expecting a non-const variable.
>
> A new macro DECLARE_HYPERCALL_BOUNCE_IN() is introduced and will take
> care of const parameter. The first user will be xc_send_debug_keys() but
> this can be used in more place in the future.
>
> Reported-by: Dario Faggioli <dfaggioli@suse.com>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index fc6e57a1a0..d8874eb846 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -1225,7 +1225,7 @@ int xc_readconsolering(xc_interface *xch, unsigned int *pnr_chars, int clear, int incremental, uint32_t *pindex); -int xc_send_debug_keys(xc_interface *xch, char *keys); +int xc_send_debug_keys(xc_interface *xch, const char *keys); int xc_set_parameters(xc_interface *xch, char *params); typedef struct xen_sysctl_physinfo xc_physinfo_t; diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c index 093fa44081..957c03415c 100644 --- a/tools/libxc/xc_misc.c +++ b/tools/libxc/xc_misc.c @@ -167,11 +167,11 @@ int xc_readconsolering(xc_interface *xch, return ret; } -int xc_send_debug_keys(xc_interface *xch, char *keys) +int xc_send_debug_keys(xc_interface *xch, const char *keys) { int ret, len = strlen(keys); DECLARE_SYSCTL; - DECLARE_HYPERCALL_BOUNCE(keys, len, XC_HYPERCALL_BUFFER_BOUNCE_IN); + DECLARE_HYPERCALL_BOUNCE_IN(keys, len); if ( xc_hypercall_bounce_pre(xch, keys) ) return -1; diff --git a/tools/libxc/xc_private.h b/tools/libxc/xc_private.h index adc3b6a571..c77edb3c4c 100644 --- a/tools/libxc/xc_private.h +++ b/tools/libxc/xc_private.h @@ -181,6 +181,14 @@ enum { */ #define DECLARE_HYPERCALL_BOUNCE(_ubuf, _sz, _dir) DECLARE_NAMED_HYPERCALL_BOUNCE(_ubuf, _ubuf, _sz, _dir) +/* + * Declare a bounce buffer shadowing the named user data pointer that + * cannot be modified. + */ +#define DECLARE_HYPERCALL_BOUNCE_IN(_ubuf, _sz) \ + DECLARE_NAMED_HYPERCALL_BOUNCE(_ubuf, (void *)(_ubuf), _sz, \ + XC_HYPERCALL_BUFFER_BOUNCE_IN) + /* * Set the size of data to bounce. Useful when the size is not known * when the bounce buffer is declared.