Rename alloc_primary_display() and __alloc_primary_display(), clarify free semantics to make interfaces easier to understand.
Rename alloc_primary_display() to lookup_primary_display() as it does not necessarily allocate. Then rename __alloc_primary_display() to the new alloc_primary_display(). The helper belongs to free_primary_display), so it should be named without underscores. The lookup helper does not necessarily allocate, so the output parameter needs_free to indicate when free should be called. Pass an argument through the calls to track this state. Put the free handling into release_primary_display() for simplificy. Also move the comment fro primary_display.c to efi-stub-entry.c, where it now describes lookup_primary_display(). Signed-off-by: Thomas Zimmermann <[email protected]> --- drivers/firmware/efi/libstub/efi-stub-entry.c | 23 +++++++++++++++++-- drivers/firmware/efi/libstub/efi-stub.c | 22 ++++++++++++------ drivers/firmware/efi/libstub/efistub.h | 2 +- .../firmware/efi/libstub/primary_display.c | 17 +------------- drivers/firmware/efi/libstub/zboot.c | 6 +++-- 5 files changed, 42 insertions(+), 28 deletions(-) diff --git a/drivers/firmware/efi/libstub/efi-stub-entry.c b/drivers/firmware/efi/libstub/efi-stub-entry.c index aa85e910fe59..3077b51fe0b2 100644 --- a/drivers/firmware/efi/libstub/efi-stub-entry.c +++ b/drivers/firmware/efi/libstub/efi-stub-entry.c @@ -14,10 +14,29 @@ static void *kernel_image_addr(void *addr) return addr + kernel_image_offset; } -struct sysfb_display_info *alloc_primary_display(void) +/* + * There are two ways of populating the core kernel's sysfb_primary_display + * via the stub: + * + * - using a configuration table, which relies on the EFI init code to + * locate the table and copy the contents; or + * + * - by linking directly to the core kernel's copy of the global symbol. + * + * The latter is preferred because it makes the EFIFB earlycon available very + * early, but it only works if the EFI stub is part of the core kernel image + * itself. The zboot decompressor can only use the configuration table + * approach. + */ + +struct sysfb_display_info *lookup_primary_display(bool *needs_free) { + *needs_free = true; + if (IS_ENABLED(CONFIG_ARM)) - return __alloc_primary_display(); + return alloc_primary_display(); + + *needs_free = false; if (IS_ENABLED(CONFIG_X86) || IS_ENABLED(CONFIG_EFI_EARLYCON) || diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index 42d6073bcd06..dc545f62c62b 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -51,14 +51,14 @@ static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0); void __weak free_primary_display(struct sysfb_display_info *dpy) { } -static struct sysfb_display_info *setup_primary_display(void) +static struct sysfb_display_info *setup_primary_display(bool *dpy_needs_free) { struct sysfb_display_info *dpy; struct screen_info *screen = NULL; struct edid_info *edid = NULL; efi_status_t status; - dpy = alloc_primary_display(); + dpy = lookup_primary_display(dpy_needs_free); if (!dpy) return NULL; screen = &dpy->screen; @@ -68,15 +68,22 @@ static struct sysfb_display_info *setup_primary_display(void) status = efi_setup_graphics(screen, edid); if (status != EFI_SUCCESS) - goto err_free_primary_display; + goto err___free_primary_display; return dpy; -err_free_primary_display: - free_primary_display(dpy); +err___free_primary_display: + if (*dpy_needs_free) + free_primary_display(dpy); return NULL; } +static void release_primary_display(struct sysfb_display_info *dpy, bool dpy_needs_free) +{ + if (dpy && dpy_needs_free) + free_primary_display(dpy); +} + static void install_memreserve_table(void) { struct linux_efi_memreserve *rsv; @@ -156,13 +163,14 @@ efi_status_t efi_stub_common(efi_handle_t handle, char *cmdline_ptr) { struct sysfb_display_info *dpy; + bool dpy_needs_free; efi_status_t status; status = check_platform_features(); if (status != EFI_SUCCESS) return status; - dpy = setup_primary_display(); + dpy = setup_primary_display(&dpy_needs_free); efi_retrieve_eventlog(); @@ -182,7 +190,7 @@ efi_status_t efi_stub_common(efi_handle_t handle, status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr); - free_primary_display(dpy); + release_primary_display(dpy, dpy_needs_free); return status; } diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 979a21818cc1..1503ffb82903 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -1176,8 +1176,8 @@ efi_enable_reset_attack_mitigation(void) { } void efi_retrieve_eventlog(void); +struct sysfb_display_info *lookup_primary_display(bool *needs_free); struct sysfb_display_info *alloc_primary_display(void); -struct sysfb_display_info *__alloc_primary_display(void); void free_primary_display(struct sysfb_display_info *dpy); void efi_cache_sync_image(unsigned long image_base, diff --git a/drivers/firmware/efi/libstub/primary_display.c b/drivers/firmware/efi/libstub/primary_display.c index cdaebab26514..34c54ac1e02a 100644 --- a/drivers/firmware/efi/libstub/primary_display.c +++ b/drivers/firmware/efi/libstub/primary_display.c @@ -7,24 +7,9 @@ #include "efistub.h" -/* - * There are two ways of populating the core kernel's sysfb_primary_display - * via the stub: - * - * - using a configuration table, which relies on the EFI init code to - * locate the table and copy the contents; or - * - * - by linking directly to the core kernel's copy of the global symbol. - * - * The latter is preferred because it makes the EFIFB earlycon available very - * early, but it only works if the EFI stub is part of the core kernel image - * itself. The zboot decompressor can only use the configuration table - * approach. - */ - static efi_guid_t primary_display_guid = LINUX_EFI_PRIMARY_DISPLAY_TABLE_GUID; -struct sysfb_display_info *__alloc_primary_display(void) +struct sysfb_display_info *alloc_primary_display(void) { struct sysfb_display_info *dpy; efi_status_t status; diff --git a/drivers/firmware/efi/libstub/zboot.c b/drivers/firmware/efi/libstub/zboot.c index 4b76f74c56da..c1fd1fdbcb08 100644 --- a/drivers/firmware/efi/libstub/zboot.c +++ b/drivers/firmware/efi/libstub/zboot.c @@ -26,9 +26,11 @@ void __weak efi_cache_sync_image(unsigned long image_base, // executable code loaded into memory to be safe for execution. } -struct sysfb_display_info *alloc_primary_display(void) +struct sysfb_display_info *lookup_primary_display(bool *needs_free) { - return __alloc_primary_display(); + *needs_free = true; + + return alloc_primary_display(); } asmlinkage efi_status_t __efiapi -- 2.51.1
